Pycom Ation Wi Py 3.0 User Guide

User Manual:

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1.1
1.2
2.1
2.2
2.2.1
2.2.2
2.2.3
2.2.4
2.2.5
2.2.6
2.3
2.3.1
2.3.2
2.3.3
2.4
2.4.1
2.4.2
2.4.3
2.4.4
2.4.4.1
2.4.4.2
2.4.5
2.4.6
2.5
2.5.1
TableofContents
About
Preface
PycomProducts
1.GettingStarted
1.0Introduction
1.1HardwareSetup
1.1.1LoPy
1.1.2LoPy4
1.1.1SiPy
1.1.1GPy
1.1.1FiPy
1.1.1WiPy
1.2Software
1.2.1Drivers
1.2.2UpdatingFirmware
1.2.3Pymakr
1.3Programmingthemodules
1.3.1IntroductiontoMicroPython
1.3.2MicroPythonExamples
1.3.3YourfirstPymakrproject
1.3.4REPL
1.3.4.1SerialUSB
1.3.4.2Telnet
1.3.5FTP
1.3.6Safeboot
1.4DeviceRegistration
1.4.1Sigfox
1
2.5.2
2.5.3
2.5.3.1
2.5.3.2
3.1
3.1.1
3.1.2
3.2
3.3
4.1
4.2
4.2.1
4.2.2
4.2.3
4.3
4.3.1
4.3.2
4.3.3
5.1
5.2
5.2.1
5.2.2
5.2.3
5.2.4
5.2.5
1.4.2Cellular
1.4.3LoRaWAN
1.4.3.2TheThingsNetwork
1.4.3.2Objenious
2.PymakrPlugin
2.1Installation
2.1.1Atom
2.1.2VisualStudioCode
2.2Tools/Features
2.3Settings
3.Pysense&Pytrack
3.1Introduction
3.2InstallingSoftware
3.2.1UpdatingFirmware
3.2.2InstallingDrivers-Windows7
3.2.3InstallingLibraries
3.3APIReference
3.3.1Pytrack
3.3.2Pysense
3.3.3Sleep
4.Tutorials&Examples
4.1Introduction
4.2AllPycomDeviceExamples
4.2.1REPL
4.2.2WLAN
4.2.3Bluetooth
4.2.4HTTPS
4.2.5MQTT
2
5.2.6
5.2.7
5.2.8
5.2.9
5.2.10
5.2.11
5.2.12
5.2.13
5.2.14
5.2.15
5.2.16
5.3
5.3.1
5.3.2
5.3.3
5.3.4
5.3.5
5.3.6
5.3.7
5.4
5.4.1
5.4.2
5.5
5.5.1
5.5.2
5.5.3
5.5.4
5.6
5.7
6.1
6.2
4.2.6AWS
4.2.7ADC
4.2.8I2C
4.2.9OnewireDriver
4.2.10Threading
4.2.11RGBLED
4.2.12Timers
4.2.13PIRSensor
4.2.14Modbus
4.2.15OTAupdate
4.2.16RMT
4.3LoRaExamples
4.3.1LoRa-MAC(RawLoRa)
4.3.2LoRaWANwithOTAA
4.3.3LoRaWANwithABP
4.3.4LoRa-MACNano-Gateway
4.3.5LoPytoLoPy
4.3.6LoRaWANNano-Gateway
4.3.7RN2483toLoPy
4.4SigfoxExamples
4.4.1RegisterDevice
4.4.2DisengageSequenceNumber
4.5LTEExamples
4.5.1CAT-M1
4.5.2NB-IoT
4.5.3ModuleIMEI
4.5.3ModemFirmwareUpdate
4.6PytrackExamples
4.7PysenseExamples
5.Firmware&APIReference
5.1Introduction
5.2PycomModules
3
6.2.1
6.2.1.1
6.2.1.2
6.2.1.3
6.2.1.4
6.2.1.5
6.2.1.6
6.2.1.7
6.2.1.8
6.2.1.9
6.2.1.10
6.2.1.11
6.2.1.12
6.2.1.13
6.2.2
6.2.2.1
6.2.2.2
6.2.2.3
6.2.2.3.1
6.2.2.3.2
6.2.2.3.3
6.2.2.3.4
6.2.2.3.5
6.2.2.3.6
6.2.2.4
6.2.2.5
6.2.2.6
6.2.3
6.2.4
6.3
6.3.1
6.3.2
6.3.3
6.3.4
5.2.1machine
5.2.1.1ADC
5.2.1.2DAC
5.2.1.3I2C
5.2.1.4Pin
5.2.1.5PWM
5.2.1.6RTC
5.2.1.7SPI
5.2.1.8UART
5.2.1.9WDT
5.2.1.10Timer
5.2.1.11SD
5.2.1.12CAN
5.2.1.13RMT
5.2.2network
5.2.2.1WLAN
5.2.2.2Server
5.2.2.3Bluetooth
5.2.2.3.1GATT
5.2.2.3.2GATTCConnection
5.2.2.3.3GATTCService
5.2.2.3.4GATTCCharacteristic
5.2.2.3.5GATTSService
5.2.2.3.6GATTSCharacteristic
5.2.2.4LoRa
5.2.2.5Sigfox
5.2.2.6LTE
5.2.3AES
5.2.4pycom
5.3MicroPythonModules
5.3.1micropython
5.3.2uctypes
5.3.3sys
5.3.4uos
4
6.3.5
6.3.6
6.3.7
6.3.8
6.3.9
6.3.10
6.3.11
6.3.12
6.3.13
6.3.14
6.3.15
6.3.16
6.3.17
6.3.18
6.3.19
6.3.20
7.1
7.2
7.2.1
7.2.2
7.2.3
7.2.4
7.2.5
7.2.6
7.2.7
7.3
7.3.1
7.3.2
7.3.3
7.3.4
5.3.5array
5.3.6cmath
5.3.7math
5.3.8gc
5.3.9ubinascii
5.3.10ujson
5.3.11ure
5.3.12usocket
5.3.13select
5.3.14utime
5.3.15uhashlib
5.3.16ussl
5.3.17ucrypto
5.3.18ustruct
5.3.19_thread
5.3.20Builtin
6.ProductInfo
6.0Introduction
6.1DevelopmentModules
6.1.1WiPy2.0
6.1.2WiPy3.0
6.1.3LoPy
6.1.4LoPy4
6.1.5SiPy
6.1.6GPy
6.1.7FiPy
6.2OEMModules
6.2.1W01
6.2.2L01
6.2.3L04
6.2.4G01
5
7.3.5
7.3.6
7.4
7.4.1
7.4.2
7.4.3
7.4.4
7.4.5
7.4.6
7.4.6.1
7.5
8.1
8.1.1
8.1.2
8.1.3
8.1.4
8.1.5
8.1.6
8.1.7
8.2
8.2.1
8.2.2
8.2.3
8.2.4
8.3
8.3.1
8.3.2
8.3.3
8.3.4
6.2.5L01OEMBaseboardReference
6.2.6UniversalOEMBaseboardReference
6.3ExpansionBoardsandShields
6.3.1ExpansionBoard3.0
6.3.2Pytrack
6.3.3Pysense
6.3.4Pyscan
6.3.5ExpansionBoard2.0
6.3.6DeepSleepShield
6.3.6.1DeepSleepAPI
6.4Notes
7.Datasheets
7.1DevelopmentModules
7.1.1WiPy2.0
7.1.2WiPy3.0
7.1.3LoPy
7.1.4LoPy4
7.1.5SiPy
7.1.6GPy
7.1.7FiPy
7.2OEMModules
7.2.1W01
7.2.2L01
7.2.3L04
7.2.4G01
7.3ExpansionBoardsandShields
7.3.1ExpansionBoard3.0
7.3.2Pytrack
7.3.3Pysense
7.3.4ExpansionBoard2.0
6
9.1
9.2
9.3
9.3.1
9.3.2
9.4
10.1
10.2
10.3
11.1
11.2
11.3
12.1
8.Pybytes
8.1Introduction
8.2GettingStarted
8.3AddadevicetoPybytes
8.3.1ConnecttoPybytes:QuickAdd
8.3.2ConnecttoPybytes:FlashPybyteslibrarymanually
8.4Visualisedatafromyourdevice
9.DocumentationNotes
9.1Introduction
9.2Syntax
9.3REPLvsScripts
10.AdvancedTopics
10.1FirmwareDowngrade
10.2CLIUpdater
10.3SecureBootandEncryption
11.License
11.1License
7
PycomDocumentation
WelcometothePycomdocumentationsite.Thedocumentationissplitinto5sections;we
recommendreadingthroughallthesectionstofamiliariseyourselfwiththevarioustoolsand
featuresavailabletoyoutohelpyoudeveloponyourPycommodule.
Togetstarted,readthroughtheGettingStartedGuidethenfeelfreetojumpstraightintothe
tutorialsandexamplesinTutorials&Examplestobeginbuildingyourprojects.
Products
GettingStarted
Tutorials
Preface
8
ProductInfo
APIDocumentation
Pybytes
Preface
9
PycomProducts
BelowyouwillfindtablesofallPycomproducts.Thesetablesillustratethefunctionalityof
ourvariousproducts,theircompatibilitywitheachother,aswellaswhataccessoriesare
requiredtoutilisecertainfunctionality.
DevelopmentBoards
PycomProducts
10
Module WiFi Bluetooth LoRa Sigfox LTECAT-M1
NB-IoT
WiPy3.0
✔ ✔
SiPy
✔ ✔ ✔
GPy
✔ ✔ ✔
LoPy
✔ ✔ ✔
LoPy4
✔ ✔ ✔ ✔
FiPy
✔ ✔ ✔ ✔ ✔
Antennas
ExternalWiFi/BT
AntennaKit
LoRa&Sigfox
AntennaKit
LTE-M
AntennaKit
Accessories
Accessory
Expansion
PycomProducts
11
Board Pysense Pytrack Pyscan
PyCase
✔
IP67Casefor
ExpansionBoard
✔
IP67Casefor
Pysense/Pytrack/Pyscan
✔✔✔
IP67Case
(universal)
✔ ✔ ✔ ✔
LiPoBattery
(user-supplied)
✔ ✔ ✔ ✔
MicroUSBCable
Required
(user-supplied)
✔ ✔ ✔ ✔
PycomProducts
12
PyscanModules
OLED
Module 2MPCamera Barcode
Reader
Fingerprint
Scanner IRImage
Sensor
✔
OEMModules
PycomProducts
13
OEMModule
L01/W01ReferenceBoard UniversalReferenceBoard
W01
✔ ✔
L01
✔ ✔
L04
✔
G01
✔
PycomProducts
14
GettingStarted
So,you'vedecidedtoorderaPycomdevelopmentmodule.Firstlywewouldliketo
congratulateyouinmakinganexcellentdecision.Ifyouhaven'tyetplacedyourorderwe
highlyrecommendyoucheckouttheproductspagebeforeyouplaceyourordertoensure
youknowwhichaccessoriesyoumightrequire.
Step1:Settingupthehardware
Inthefirstpartofthisgettingstartedguide,wewilltakeyouthroughsettingupyourdevice.
FirstlywewillcoverhowtoconnectthemoduletoyourcomputereitherviaUSBorWiFi.
SecondlywewillexplainhowtoconnectvariousaccessoriessuchasantennasorSIMcards
toyourmodule.
Step2:Settingupyourcomputer
Nowthatyourmoduleissuccessfullyconnected,youwillneedtoinstallsomesoftwareon
yourcomputertointerfacewithit.Thesecondpartofthisguidewillguideyouthrough
installingdrivers;performingfirmwareupdatesforyourmodule/accessoriestoensureyou
havethemoststableandfeaturepackedversion;andhowtosetupthesoftwareuseto
programthedevice.
1.0Introduction
15
Step3:Usingyourmodule
Nowthatyouhaveaconnectedmoduleandalltherequiredsoftwareinstalleditistimeto
beginprogrammingyourdevice.Thispartoftheguidewillgetyoustartedwithabasic
exampleandpointyouintherightdirectionforgettingyourdeviceconnectedtoyourchosen
network.
Step4:Connectingtoanetwork
Nowthatyoufamiliarwithprogrammingyourdeviceyouwillnodoubtbekeentogetit
connectedtooneoftheadvertisedwirelessnetworks.Thisusuallyrequiressome
registration.Thisstepwilldetailhowtogetregisteredandconnectedtovariouswireless
networks.
Youcannavigatethroughthisguideusingthearrowbuttonsontheleftandrightofthe
screen(oratthebottomifyouareusingmobile).
1.0Introduction
16
Settingupthehardware
ThischapterofthedocumentationwillshowyouhowtoconnectyouPycommodule.For
eachdevicetherearedetailedinstructionsonhowtoconnectyourmoduletooneofour
baseboards,aUSBUARTadapterorWiFiaswellaswhatantennasyoumightneedto
connect.Pleaseselectyourmodulebelowtobetakentotheappropriateguide.
1.1HardwareSetup
17
1.1HardwareSetup
18
1.1HardwareSetup
19
LoPy
Basicconnection
ExpBoard2.0
ExpBoard3.0
Pysense/Pytrack/Pyscan
USBUARTAdapter
WiFi
Lookfortheresetbuttononthemodule(locatedatacorneroftheboard,nexttothe
LED).
LocatetheUSBconnectorontheexpansionboard.
InserttheLoPymoduleonthetheexpansionboardwiththeresetbuttonpointing
towardstheUSBconnector.Itshouldfirmlyclickintoplaceandthepinsshouldnowno
longerbevisible.
BeforeconnectingyourmoduletoanExpansionBoard3.0,youshouldupdatethe
firmwareontheExpansionBoard3.0.Instructionsonhowtodothiscanbefoundhere.
Lookfortheresetbuttononthemodule(locatedatacorneroftheboard,nexttothe
LED).
1.1.1LoPy
20
LocatetheUSBconnectorontheexpansionboard.
InserttheLoPymoduleontheExpansionBoardwiththeresetbuttonpointingtowards
theUSBconnector.Itshouldfirmlyclickintoplaceandthepinsshouldnownolonger
bevisible.
BeforeconnectingyourmoduletoaPysense/Pytrack/Pyscanboard,youshouldupdate
thefirmwareonthePysense/Pytrack/Pyscan.Instructionsonhowtodothiscanbe
foundhere.
LookfortheresetbuttonontheLoPymodule(locatedatacorneroftheboard,nextto
theLED).
LocatetheUSBconnectoronthePysense/Pytrack/Pyscan.
InsertthemoduleonthePysense/Pytrack/Pyscanwiththeresetbuttonpointingtowards
theUSBconnector.Itshouldfirmlyclickintoplaceandthepinsshouldnownolonger
bevisible.
1.1.1LoPy
21
Onceyouhavecompletedtheabovestepssuccessfullyyoushouldseetheon-boardLED
blinkingblue.Thisindicatesthedeviceispoweredupandrunning.
FirstlyyouwillneedtoconnectpowertoyourLoPy.Youwillneedtosupply
3.5v-5.5vtothe Vinpin.Note:Donotfeed 3.3vdirectlytothe 3.3vsupplypin,
thiswilldamagetheregulator.
Theconnectthe RXand TXofyourUSBUARTtothe TXand RXoftheLoPy
respectively.Note:PleaseensureyouhavethesignalleveloftheUARTadaptersetto
3.3vbeforeconnectingit.
InordertoputtheLoPyintobootloadermodetoupdatethedevicefirmwareyouwill
needtoconnect P2to GND.Werecommendyouconnectabuttonbetweenthetwoto
makethissimpler.
Note:Thismethodofconnectionisnotrecommendedforfirsttimeusers.Itispossibleto
lockyourselfoutofthedevice,requiringaUSBconnection.
1.1.1LoPy
22
InordertoaccesstheLoPyviaWiFiyouonlyneedtoprovide3.5v- 5.5vonthe
VinpinoftheLoPy:
Bydefault,whentheLoPyboots,itwillcreateaWiFiaccesspointwiththefollowing
credentials:
SSID: lopy-wlan
password: www.pycom.io
OnceconnectedtothisnetworkyouwillbeabletoaccessthetelnetandFTP
serversrunningontheLoPy.Forbothofthesethelogindetailsare:
username: micro
password: python
Antennas
LoRa
IfyouintendonusingtheLoRaconnectivityoftheLoPyyoumustconnectaLoRa
antennatoyourLoPybeforetryingtouseLoRaotherwiseyouriskdamagingthedevice.
1.1.1LoPy
23
TheLoPyonlysupportsLoRaonthe868MHzor915MHzbands.Itdoesnotsupport
433MHz.ForthisyouwillrequireaLoPy4.
FirstlyyouwillneedtoconnecttheU.FLtoSMApigtailtotheLoPyusingtheU.FL
connectoronthesamesideoftheLoPyastheLED.
Ifyouareusingapycase,youwillnextneedtoputtheSMAconnectorthroughthe
antennahole,ensuringyoualigntheflatedgecorrectly,andscrewdowntheconnector
usingtheprovidednut.
FinallyyouwillneedtoscrewontheantennatotheSMAconnector.
WiFi/Bluetooth(optional)
AllPycommodules,includingtheLoPy,comewithaon-boardWiFiantennaaswellasa
U.FLconnectorforanexternalantenna.Theexternalantennaisoptionalandonlyrequiredif
youneedbetterperformanceoraremountingtheLoPyinsuchawaythattheWiFisignalis
1.1.1LoPy
24
blocked.Switchingbetweentheantennasisdoneviasoftware,instructionsforthiscanbe
foundhere.
DeepSleepcurrentissue
TheLoPy,SiPy,andWiPy2.0experienceanissuewherethemodulesmaintainahigh
currentconsumptionindeepsleepmode.Thisissuehasbeenresolvedinallnewer
products.ThecauseforthisissueistheDCtoDCswitchmodeconverterremainsinahigh
performancemodeevenwhenthedeviceisindeepsleep.Theflashmemorychipalsodoes
notpowerdown.Amoredetailedexplanationcanbefoundhere.
1.1.1LoPy
25
LoPy4
Basicconnection
ExpBoard2.0
ExpBoard3.0
Pysense/Pytrack/Pyscan
USBUARTAdapter
WiFi
Lookfortheresetbuttononthemodule(locatedatacorneroftheboard,nexttothe
LED).
LocatetheUSBconnectorontheexpansionboard.
InserttheLoPy4moduleonthetheexpansionboardwiththeresetbuttonpointing
towardstheUSBconnector.Itshouldfirmlyclickintoplaceandthepinsshouldnowno
longerbevisible.
BeforeconnectingyourmoduletoanExpansionBoard3.0,youshouldupdatethe
firmwareontheExpansionBoard3.0.Instructionsonhowtodothiscanbefoundhere.
Lookfortheresetbuttononthemodule(locatedatacorneroftheboard,nexttothe
LED).
1.1.2LoPy4
26
LocatetheUSBconnectorontheexpansionboard.
InserttheLoPy4moduleontheExpansionBoardwiththeresetbuttonpointingtowards
theUSBconnector.Itshouldfirmlyclickintoplaceandthepinsshouldnownolonger
bevisible.
BeforeconnectingyourmoduletoaPysense/Pytrack/Pyscanboard,youshouldupdate
thefirmwareonthePysense/Pytrack/Pyscan.Instructionsonhowtodothiscanbe
foundhere.
LookfortheresetbuttonontheLoPy4module(locatedatacorneroftheboard,nextto
theLED).
LocatetheUSBconnectoronthePysense/Pytrack/Pyscan.
InsertthemoduleonthePysense/Pytrack/Pyscanwiththeresetbuttonpointingtowards
theUSBconnector.Itshouldfirmlyclickintoplaceandthepinsshouldnownolonger
bevisible.
1.1.2LoPy4
27
Onceyouhavecompletedtheabovestepssuccessfullyyoushouldseetheon-boardLED
blinkingblue.Thisindicatesthedeviceispoweredupandrunning.
FirstlyyouwillneedtoconnectpowertoyourLoPy4.Youwillneedtosupply
3.5v-5.5vtothe Vinpin.Note:Donotfeed 3.3vdirectlytothe 3.3vsupplypin,
thiswilldamagetheregulator.
Theconnectthe RXand TXofyourUSBUARTtothe TXand RXoftheLoPy4
respectively.Note:PleaseensureyouhavethesignalleveloftheUARTadaptersetto
3.3vbeforeconnectingit.
InordertoputtheLoPy4intobootloadermodetoupdatethedevicefirmwareyouwill
needtoconnect P2to GND.Werecommendyouconnectabuttonbetweenthetwoto
makethissimpler.
1.1.2LoPy4
28
Note:Thismethodofconnectionisnotrecommendedforfirsttimeusers.Itispossibleto
lockyourselfoutofthedevice,requiringaUSBconnection.
InordertoaccesstheLoPy4viaWiFiyouonlyneedtoprovide 3.5v- 5.5vonthe
VinpinoftheLoPy4:
Bydefault,whentheLoPy4boots,itwillcreateaWiFiaccesspointwiththefollowing
credentials:
SSID: lopy4-wlan
password: www.pycom.io
OnceconnectedtothisnetworkyouwillbeabletoaccessthetelnetandFTP
serversrunningontheLoPy4.Forbothofthesethelogindetailsare:
username: micro
password: python
Antennas
LoRa/Sigfox
IfyouintendonusingtheLoRa/SigfoxconnectivityoftheLoPy4youmustconnecta
LoRa/SigfoxantennatoyourLoPy4beforetryingtouseLoRa/Sigfoxotherwiseyourisk
damagingthedevice.
1.1.2LoPy4
29
FirstlyyouwillneedtoconnecttheU.FLtoSMApigtailtotheLoPy4usingoneofthe
twotheU.FLconnectorsonthesamesideoftheLoPy4astheLED.Theoneontheleft
handsideisfor433MHz(LoRaonly),theoneoftherighthandsideisfor
868MHz/915MHz(LoRa&Sigfox).Note:ThisisdifferentfromtheLoPy.
Ifyouareusingapycase,youwillnextneedtoputtheSMAconnectorthroughthe
antennahole,ensuringyoualigntheflatedgecorrectly,andscrewdowntheconnector
usingtheprovidednut.
FinallyyouwillneedtoscrewontheantennatotheSMAconnector.
WiFi/Bluetooth(optional)
1.1.2LoPy4
30
AllPycommodules,includingtheLoPy4,comewithaon-boardWiFiantennaaswellasa
U.FLconnectorforanexternalantenna.Theexternalantennaisoptionalandonlyrequiredif
youneedbetterperformanceoraremountingtheLoPy4insuchawaythattheWiFisignal
isblocked.Switchingbetweentheantennasisdoneviasoftware,instructionsforthiscanbe
foundhere.
1.1.2LoPy4
31
SiPy
Basicconnection
ExpBoard2.0
ExpBoard3.0
Pysense/Pytrack/Pyscan
USBUARTAdapter
WiFi
Lookfortheresetbuttononthemodule(locatedatacorneroftheboard,nexttothe
LED).
LocatetheUSBconnectorontheexpansionboard.
InserttheSiPymoduleonthetheexpansionboardwiththeresetbuttonpointing
towardstheUSBconnector.Itshouldfirmlyclickintoplaceandthepinsshouldnowno
longerbevisible.
BeforeconnectingyourmoduletoanExpansionBoard3.0,youshouldupdatethe
firmwareontheExpansionBoard3.0.Instructionsonhowtodothiscanbefoundhere.
Lookfortheresetbuttononthemodule(locatedatacorneroftheboard,nexttothe
LED).
1.1.1SiPy
32
LocatetheUSBconnectorontheexpansionboard.
InserttheSiPymoduleontheExpansionBoardwiththeresetbuttonpointingtowards
theUSBconnector.Itshouldfirmlyclickintoplaceandthepinsshouldnownolonger
bevisible.
BeforeconnectingyourmoduletoaPysense/Pytrack/Pyscanboard,youshouldupdate
thefirmwareonthePysense/Pytrack/Pyscan.Instructionsonhowtodothiscanbe
foundhere.
LookfortheresetbuttonontheSiPymodule(locatedatacorneroftheboard,nextto
theLED).
LocatetheUSBconnectoronthePysense/Pytrack/Pyscan.
InsertthemoduleonthePysense/Pytrack/Pyscanwiththeresetbuttonpointingtowards
theUSBconnector.Itshouldfirmlyclickintoplaceandthepinsshouldnownolonger
bevisible.
1.1.1SiPy
33
Onceyouhavecompletedtheabovestepssuccessfullyyoushouldseetheon-boardLED
blinkingblue.Thisindicatesthedeviceispoweredupandrunning.
FirstlyyouwillneedtoconnectpowertoyourSiPy.Youwillneedtosupply 3.5v-5.5v
tothe Vinpin.Note:Donotfeed 3.3vdirectlytothe 3.3vsupplypin,thiswill
damagetheregulator.
Theconnectthe RXand TXofyourUSBUARTtothe TXand RXoftheSiPy
respectively.Note:PleaseensureyouhavethesignalleveloftheUARTadaptersetto
3.3vbeforeconnectingit.
InordertoputtheSiPyintobootloadermodetoupdatethedevicefirmwareyouwill
needtoconnect P2to GND.Werecommendyouconnectabuttonbetweenthetwoto
makethissimpler.
Note:Thismethodofconnectionisnotrecommendedforfirsttimeusers.Itispossibleto
lockyourselfoutofthedevice,requiringaUSBconnection.
1.1.1SiPy
34
InordertoaccesstheSiPyviaWiFiyouonlyneedtoprovide 3.5v- 5.5vonthe
VinpinoftheSiPy:
Bydefault,whentheSiPyboots,itwillcreateaWiFiaccesspointwiththefollowing
credentials:
SSID: sipy-wlan
password: www.pycom.io
OnceconnectedtothisnetworkyouwillbeabletoaccessthetelnetandFTP
serversrunningontheSiPy.Forbothofthesethelogindetailsare:
username: micro
password: python
Antennas
Sigfox
IfyouintendonusingtheSigfoxconnectivityoftheSiPyyoumustconnectaSigfox
antennatoyourSiPybeforetryingtouseSigfoxotherwiseyouriskdamagingthe
device.
FirstlyyouwillneedtoconnecttheU.FLtoSMApigtailtotheSiPyusingtheU.FL
1.1.1SiPy
35
connectoronthesamesideoftheSiPyastheLED.
Ifyouareusingapycase,youwillnextneedtoputtheSMAconnectorthroughthe
antennahole,ensuringyoualigntheflatedgecorrectly,andscrewdowntheconnector
usingtheprovidednut.
FinallyyouwillneedtoscrewontheantennatotheSMAconnector.
WiFi/Bluetooth(optional)
AllPycommodules,includingtheSiPy,comewithaon-boardWiFiantennaaswellasa
U.FLconnectorforanexternalantenna.Theexternalantennaisoptionalandonlyrequiredif
youneedbetterperformanceoraremountingtheSiPyinsuchawaythattheWiFisignalis
blocked.Switchingbetweentheantennasisdoneviasoftware,instructionsforthiscanbe
foundhere.
1.1.1SiPy
36
DeepSleepcurrentissue
TheLoPy,SiPy,andWiPy2.0experienceanissuewherethemodulesmaintainahigh
currentconsumptionindeepsleepmode.Thisissuehasbeenresolvedinallnewer
products.ThecauseforthisissueistheDCtoDCswitchmodeconverterremainsinahigh
performancemodeevenwhenthedeviceisindeepsleep.Theflashmemorychipalsodoes
notpowerdown.Amoredetailedexplanationcanbefoundhere.
1.1.1SiPy
37
GPy
Basicconnection
ExpBoard2.0
ExpBoard3.0
Pysense/Pytrack/Pyscan
USBUARTAdapter
WiFi
Lookfortheresetbuttononthemodule(locatedatacorneroftheboard,nexttothe
LED).
LocatetheUSBconnectorontheexpansionboard.
InserttheGPymoduleonthetheexpansionboardwiththeresetbuttonpointing
towardstheUSBconnector.Itshouldfirmlyclickintoplaceandthepinsshouldnowno
longerbevisible.
BeforeconnectingyourmoduletoanExpansionBoard3.0,youshouldupdatethe
firmwareontheExpansionBoard3.0.Instructionsonhowtodothiscanbefoundhere.
Lookfortheresetbuttononthemodule(locatedatacorneroftheboard,nexttothe
LED).
1.1.1GPy
38
LocatetheUSBconnectorontheexpansionboard.
InserttheGPymoduleontheExpansionBoardwiththeresetbuttonpointingtowards
theUSBconnector.Itshouldfirmlyclickintoplaceandthepinsshouldnownolonger
bevisible.
BeforeconnectingyourmoduletoaPysense/Pytrack/Pyscanboard,youshouldupdate
thefirmwareonthePysense/Pytrack/Pyscan.Instructionsonhowtodothiscanbe
foundhere.
LookfortheresetbuttonontheGPymodule(locatedatacorneroftheboard,nextto
theLED).
LocatetheUSBconnectoronthePysense/Pytrack/Pyscan.
InsertthemoduleonthePysense/Pytrack/Pyscanwiththeresetbuttonpointingtowards
theUSBconnector.Itshouldfirmlyclickintoplaceandthepinsshouldnownolonger
bevisible.
1.1.1GPy
39
Onceyouhavecompletedtheabovestepssuccessfullyyoushouldseetheon-boardLED
blinkingblue.Thisindicatesthedeviceispoweredupandrunning.
FirstlyyouwillneedtoconnectpowertoyourGPy.Youwillneedtosupply 3.5v-5.5v
tothe Vinpin.Note:Donotfeed 3.3vdirectlytothe 3.3vsupplypin,thiswill
damagetheregulator.
Theconnectthe RXand TXofyourUSBUARTtothe TXand RXoftheGPy
respectively.Note:PleaseensureyouhavethesignalleveloftheUARTadaptersetto
3.3vbeforeconnectingit.
InordertoputtheGPyintobootloadermodetoupdatethedevicefirmwareyouwill
needtoconnect P2to GND.Werecommendyouconnectabuttonbetweenthetwoto
makethissimpler.
1.1.1GPy
40
Note:Thismethodofconnectionisnotrecommendedforfirsttimeusers.Itispossibleto
lockyourselfoutofthedevice,requiringaUSBconnection.
InordertoaccesstheGPyviaWiFiyouonlyneedtoprovide3.5v- 5.5vonthe
VinpinoftheGPy:
Bydefault,whentheGPyboots,itwillcreateaWiFiaccesspointwiththefollowing
credentials:
SSID: gpy-wlan
password: www.pycom.io
OnceconnectedtothisnetworkyouwillbeabletoaccessthetelnetandFTP
serversrunningontheGPy.Forbothofthesethelogindetailsare:
username: micro
password: python
Antennas
LTECat-M1/NB-IoT
IfyouintendonusingtheLTECAT-M1orNB-IoTconnectivityoftheGPyyoumustconnect
aLTECAT-M1/NB-IoTantennatoyourGPybeforetryingtouseLTECat-M1orNB-IoT
otherwiseyouriskdamagingthedevice.
1.1.1GPy
41
YouwillneedtoconnecttheantennatotheGPyusingtheU.FLconnectoronthesame
sideoftheGPyastheLED.
WiFi/Bluetooth(optional)
AllPycommodules,includingtheGPy,comewithaon-boardWiFiantennaaswellasa
U.FLconnectorforanexternalantenna.Theexternalantennaisoptionalandonlyrequiredif
youneedbetterperformanceoraremountingtheGPyinsuchawaythattheWiFisignalis
blocked.Switchingbetweentheantennasisdoneviasoftware,instructionsforthiscanbe
foundhere.
1.1.1GPy
42
SIMcard
IfyouintendonusingtheLTECAT-M1orNB-IoTconnectivityoftheGPyyouwillneedto
insertaSIMcardintoyourGPy.ItshouldbenotedthattheGPydoesnotsupportregular
LTEconnectivityandyoumayrequireaspecialSIM.Itisbesttocontactyourlocalcellular
providersformoreinformationonacquiringaLTECAT-M1/NB-IoTenablednanoSIM.
1.1.1GPy
43
FiPy
Basicconnection
ExpBoard2.0
ExpBoard3.0
Pysense/Pytrack/Pyscan
USBUARTAdapter
WiFi
WhenusingtheexpansionboardwithaFiPy,youwillneedtoremovetheCTSandRTS
jumpersastheseinterferewithcommunicationwiththecellularmodem.
Lookfortheresetbuttononthemodule(locatedatacorneroftheboard,nexttothe
LED).
LocatetheUSBconnectorontheexpansionboard.
InserttheFiPymoduleonthetheexpansionboardwiththeresetbuttonpointing
towardstheUSBconnector.Itshouldfirmlyclickintoplaceandthepinsshouldnowno
longerbevisible.
BeforeconnectingyourmoduletoanExpansionBoard3.0,youshouldupdatethe
firmwareontheExpansionBoard3.0.Instructionsonhowtodothiscanbefoundhere.
1.1.1FiPy
44
WhenusingtheexpansionboardwithaFiPy,youwillneedtoremovetheCTSandRTS
jumpersastheseinterferewithcommunicationwiththecellularmodem.
Lookfortheresetbuttononthemodule(locatedatacorneroftheboard,nexttothe
LED).
LocatetheUSBconnectorontheexpansionboard.
InserttheFiPymoduleontheExpansionBoardwiththeresetbuttonpointingtowards
theUSBconnector.Itshouldfirmlyclickintoplaceandthepinsshouldnownolonger
bevisible.
BeforeconnectingyourmoduletoaPysense/Pytrack/Pyscanboard,youshouldupdate
thefirmwareonthePysense/Pytrack/Pyscan.Instructionsonhowtodothiscanbe
foundhere.
LookfortheresetbuttonontheFiPymodule(locatedatacorneroftheboard,nextto
theLED).
LocatetheUSBconnectoronthePysense/Pytrack/Pyscan.
InsertthemoduleonthePysense/Pytrack/Pyscanwiththeresetbuttonpointingtowards
theUSBconnector.Itshouldfirmlyclickintoplaceandthepinsshouldnownolonger
bevisible.
1.1.1FiPy
45
Onceyouhavecompletedtheabovestepssuccessfullyyoushouldseetheon-boardLED
blinkingblue.Thisindicatesthedeviceispoweredupandrunning.
FirstlyyouwillneedtoconnectpowertoyourFiPy.Youwillneedtosupply 3.5v-5.5v
tothe Vinpin.Note:Donotfeed 3.3vdirectlytothe 3.3vsupplypin,thiswill
damagetheregulator.
Theconnectthe RXand TXofyourUSBUARTtothe TXand RXoftheFiPy
respectively.Note:PleaseensureyouhavethesignalleveloftheUARTadaptersetto
3.3vbeforeconnectingit.
InordertoputtheFiPyintobootloadermodetoupdatethedevicefirmwareyouwill
needtoconnect P2to GND.Werecommendyouconnectabuttonbetweenthetwoto
makethissimpler.
Note:Thismethodofconnectionisnotrecommendedforfirsttimeusers.Itispossibleto
lockyourselfoutofthedevice,requiringaUSBconnection.
InordertoaccesstheFiPyviaWiFiyouonlyneedtoprovide 3.5v- 5.5vonthe
1.1.1FiPy
46
VinpinoftheFiPy:
Bydefault,whentheFiPyboots,itwillcreateaWiFiaccesspointwiththefollowing
credentials:
SSID: fipy-wlan
password: www.pycom.io
OnceconnectedtothisnetworkyouwillbeabletoaccessthetelnetandFTP
serversrunningontheFiPy.Forbothofthesethelogindetailsare:
username: micro
password: python
Antennas
LoRa/Sigfox
IfyouintendonusingtheLoRa/SigfoxconnectivityoftheFiPyyoumustconnecta
LoRa/SigfoxantennatoyourFiPybeforetryingtouseLoRa/Sigfoxotherwiseyourisk
damagingthedevice.
1.1.1FiPy
47
TheFiPyonlysupportsLoRaonthe868MHzor915MHzbands.Itdoesnotsupport
433MHz.ForthisyouwillrequireaLoPy4.
FirstlyyouwillneedtoconnecttheU.FLtoSMApigtailtotheFiPyusingtheU.FL
connectoronthesamesideoftheFiPyastheLED.
Ifyouareusingapycase,youwillnextneedtoputtheSMAconnectorthroughthe
antennahole,ensuringyoualigntheflatedgecorrectly,andscrewdowntheconnector
usingtheprovidednut.
FinallyyouwillneedtoscrewontheantennatotheSMAconnector.
LTECat-M1/NB-IoT
IfyouintendonusingtheLTECAT-M1orNB-IoTconnectivityoftheFiPyyoumustconnect
aLTECAT-M1/NB-IoTantennatoyourFiPybeforetryingtouseLTECat-M1orNB-IoT
otherwiseyouriskdamagingthedevice.
1.1.1FiPy
48
YouwillneedtoconnecttheantennatotheFiPyusingtheU.FLconnectorontheunder
sideoftheFiPy.
WiFi/Bluetooth(optional)
AllPycommodules,includingtheFiPy,comewithaon-boardWiFiantennaaswellasa
U.FLconnectorforanexternalantenna.Theexternalantennaisoptionalandonlyrequiredif
youneedbetterperformanceoraremountingtheFiPyinsuchawaythattheWiFisignalis
blocked.Switchingbetweentheantennasisdoneviasoftware,instructionsforthiscanbe
foundhere.
1.1.1FiPy
49
SIMcard
IfyouintendonusingtheLTECAT-M1orNB-IoTconnectivityoftheFiPyyouwillneedto
insertaSIMcardintoyourFiPy.ItshouldbenotedthattheFiPydoesnotsupportregular
LTEconnectivityandyoumayrequireaspecialSIM.Itisbesttocontactyourlocalcellular
providersformoreinformationonacquiringaLTECAT-M1/NB-IoTenablednanoSIM.
1.1.1FiPy
50
WiPy
Basicconnection
ExpBoard2.0
ExpBoard3.0
Pysense/Pytrack/Pyscan
USBUARTAdapter
WiFi
Lookfortheresetbuttononthemodule(locatedatacorneroftheboard,nexttothe
LED).
LocatetheUSBconnectorontheexpansionboard.
InserttheWiPymoduleonthetheexpansionboardwiththeresetbuttonpointing
towardstheUSBconnector.Itshouldfirmlyclickintoplaceandthepinsshouldnowno
longerbevisible.
BeforeconnectingyourmoduletoanExpansionBoard3.0,youshouldupdatethe
firmwareontheExpansionBoard3.0.Instructionsonhowtodothiscanbefoundhere.
Lookfortheresetbuttononthemodule(locatedatacorneroftheboard,nexttothe
LED).
1.1.1WiPy
51
LocatetheUSBconnectorontheexpansionboard.
InserttheWiPymoduleontheExpansionBoardwiththeresetbuttonpointingtowards
theUSBconnector.Itshouldfirmlyclickintoplaceandthepinsshouldnownolonger
bevisible.
BeforeconnectingyourmoduletoaPysense/Pytrack/Pyscanboard,youshouldupdate
thefirmwareonthePysense/Pytrack/Pyscan.Instructionsonhowtodothiscanbe
foundhere.
LookfortheresetbuttonontheWiPymodule(locatedatacorneroftheboard,nextto
theLED).
LocatetheUSBconnectoronthePysense/Pytrack/Pyscan.
InsertthemoduleonthePysense/Pytrack/Pyscanwiththeresetbuttonpointingtowards
theUSBconnector.Itshouldfirmlyclickintoplaceandthepinsshouldnownolonger
bevisible.
1.1.1WiPy
52
Onceyouhavecompletedtheabovestepssuccessfullyyoushouldseetheon-boardLED
blinkingblue.Thisindicatesthedeviceispoweredupandrunning.
FirstlyyouwillneedtoconnectpowertoyourWiPy.Youwillneedtosupply
3.5v-5.5vtothe Vinpin.Note:Donotfeed 3.3vdirectlytothe 3.3vsupplypin,
thiswilldamagetheregulator.
Theconnectthe RXand TXofyourUSBUARTtothe TXand RXoftheWiPy
respectively.Note:PleaseensureyouhavethesignalleveloftheUARTadaptersetto
3.3vbeforeconnectingit.
InordertoputtheWiPyintobootloadermodetoupdatethedevicefirmwareyouwill
needtoconnect P2to GND.Werecommendyouconnectabuttonbetweenthetwoto
makethissimpler.
Note:Thismethodofconnectionisnotrecommendedforfirsttimeusers.Itispossibleto
lockyourselfoutofthedevice,requiringaUSBconnection.
1.1.1WiPy
53
InordertoaccesstheWiPyviaWiFiyouonlyneedtoprovide 3.5v- 5.5vonthe
VinpinoftheWiPy:
Bydefault,whentheWiPyboots,itwillcreateaWiFiaccesspointwiththefollowing
credentials:
SSID: wipy-wlan
password: www.pycom.io
OnceconnectedtothisnetworkyouwillbeabletoaccessthetelnetandFTP
serversrunningontheWiPy.Forbothofthesethelogindetailsare:
username: micro
password: python
Antennas
WiFi/Bluetooth(optional)
AllPycommodules,includingtheWiPy,comewithaon-boardWiFiantennaaswellasa
U.FLconnectorforanexternalantenna.Theexternalantennaisoptionalandonlyrequiredif
youneedbetterperformanceoraremountingtheWiPyinsuchawaythattheWiFisignalis
blocked.Switchingbetweentheantennasisdoneviasoftware,instructionsforthiscanbe
foundhere.
1.1.1WiPy
54
DeepSleepcurrentissue
TheLoPy,SiPy,andWiPy2.0experienceanissuewherethemodulesmaintainahigh
currentconsumptionindeepsleepmode.Thisissuehasbeenresolvedinallnewer
products.ThecauseforthisissueistheDCtoDCswitchmodeconverterremainsinahigh
performancemodeevenwhenthedeviceisindeepsleep.Theflashmemorychipalsodoes
notpowerdown.Amoredetailedexplanationcanbefoundhere.
WiPy2.0vsWiPy3.0
TheWiPy3.0isanupgradedversionoftheWiPy2.0withthefollowingchanges:
TheFLASHhasbeenupgradedfrom4MBto8MB.
TheRAMhasbeenupgradedfrom512KBto4MB.
Thedeepsleepcurrentconsumptionissuehasbeenfixed
TheantennaselectpinhasmovedtoGPIO21(P12)
1.1.1WiPy
55
Settingupyourcomputer
Togetyouupandrunning,Pycomprovidesasuiteoftoolstoassistwithdevelopingand
programmingyourPycomDevices:
1. Drivers:IfyouareusingMicrosoftWindows,youmightberequiredtoinstalldriversfor
ourproductstofunctioncorrectly.
2. Pycomfirmwareupdateutility:Thistoolautomatestheprocessofupgradingthe
firmwareofyourPycomdevice.Itisimportantthatyouusethistoolbeforeyouattempt
touseyourdevice.Notonlytoensureyouhavethemoststableandfeaturepacked
firmware,butalsotoensureallthefunctionalityofyourdeviceisenable.E.g.thistool
alsoactivatesyourtwoyearfreesigfoxconnectivity.
3. DevelopmentEnvironment:Pymakrisaplug-inforAtomandVisualStudioCode
developedbyPycomtomakedevelopmentforPycommodulessupereasy.Itallows
youtouseyourfavouritetexteditorwhilesimplifyingtheprocessofuploadingcodeto
thedevice.
1.2Software
56
Drivers
Linux
YoushouldnotneedtoinstallanydriversforourdevicestoberecognisedbyLinux.You
mayhoweverneedtoadjustpermissionstomakesureyouhaveaccesstotheserialport.
Onmostdistributionsthiscanbedonebyaddingyourusertothe dialoutusergroup.
Pleasecheckthespecificinstructionsforyourlinuxdistributionforhowtodothis.
macOS
OnmacOSyoushouldn'tneedtodoanythingspecialtogetourdevicetowork.
Windows
AllourproductswillworkoutoftheboxforWindows8/10/+.IfusingWindows7,driversto
supportthePysense/Pytrack/Pyscan/ExpansionBoard3.0boardswillneedtobeinstalled.
Download
Pleasedownloadthedriversoftwarefromthelinkbelow.
Pysense/Pytrack/Pyscan/ExpansionBoard3.0SerialDriver
Installation
FirstnavigateopentheWindowsstartmenuandsearch/navigateto`DeviceManager.You
shouldseeyourPytrack/Pysenseinthedropdownunderotherdevices.
1.2.1Drivers
57
Rightclickthedeviceandselect UpdateDriverSoftware.
SelecttheoptiontoBrowsemycomputerfordriversoftware.
1.2.1Drivers
58
Nextyouwillneedtonavigatetowhereyoudownloadedthedriverto(e.g.Downloads
Folder).
Specifythefolderinwhichthedriversarecontained.Ifyouhaven'textractedthe .zipfile,
pleasedothisbeforeselectingthefolder.
1.2.1Drivers
59
Youmayreceiveawarning,suggestingthatWindowscan'tverifythepublisherofthisdriver.
Click Installthisdriversoftwareanywayasthislinkpointstoourofficialdriver.
Iftheinstallationwassuccessful,youshouldnowseeawindowspecifyingthatthedriver
wascorrectlyinstalled.
1.2.1Drivers
60
Toconfirmthattheinstallationwascorrect,navigatebacktothe DeviceManagerandclick
thedropdownforotherdevices.Thewarninglabelshouldnowbegoneand
Pytrack/Pysenseshouldbeinstalled.
1.2.1Drivers
61
FirmwareUpdateTools
Westronglyrecommendyoutoupgradeyourfirmwaretothelatestversionasweare
constantlymakingimprovementsandaddingnewfeaturestothedevices.
Herearethedownloadlinkstotheupdatetool.Pleasedownloadtheappropriateonefor
yourOSandfollowtheinstructionsonthescreen.
Windows
macOS(10.11orHigher)
Linux(requires dialogand python-serialpackage)
Previousversionsoffirmwareareavailablefordownloadhere.
UpdatingDeviceFirmware
Thebasicfirmwareupgradeprocedurecanbefoundbelow,pleasefollowthesesteps
carefully:
ExpansionBoard2.0
Pysense/Pytrack/Pyscan/ExpansionBoard3.0
1. Disconnectyourdevicefromyourcomputer
2. InsertmoduleintotheExpansionBoard
3. Connectajumpercableorwirebetween G23andGND
4. ReconnecttheboardviaUSBtoyourcomputer,thisputsthedevicein‘firmwareupdate
mode’.
5. RuntheFirmwareUpgradetool
1.2.2UpdatingFirmware
62
6. Removethe G23to GNDjumpercable/wire
7. Rebootthedevice(buttonorpoweroffthenon),yourdeviceisnowreadytouse
Ifyouarehavinganyissues,makesuretheTXandRXjumpersarepresentonyour
ExpansionBoard,asthejumperssometimescomelooseintheboxduringtransport.
Withoutthesejumpers,theupdaterwillfail.
WhenusingaPysense/Pytrack/Pyscan/ExpansionBoard3.0toupdateyourmoduleyouare
notrequiredtomakeaconnectionbetween G23and GND,the
Pysense/Pytrack/Pyscan/ExpansionBoard3.0willdothisautomatically.
1. BeforeconnectingyourmoduletoaPysense/Pytrackboard,youshouldupdatethe
firmwareonthePysense/Pytrack.Instructionsonhowtodothiscanbefoundhere.
2. Disconnectyourdevicefromyourcomputer
3. InsertmoduleintoExpansionBoard
4. ReconnecttheboardviaUSBtoyourcomputer
5. RuntheFirmwareUpgradetool
1.2.2UpdatingFirmware
63
6. DisconnecttheUSBcablefromtheboardandreconnectit,yourdeviceisnowreadyto
use
Afteryou’redonewithupgrading,youcanusethePymakrPluginstouploadandrun
programsinyourdevice.
1.2.2UpdatingFirmware
64
PymakrPlugins
TomakeitaseasyaspossiblePycomhasdevelopedapluginfortwopopulartexteditors,
calledPymakr.Thesepluginshavebeenbuiltandareavailableforthefollowingplatforms:
1.2.3Pymakr
65
1.2.3Pymakr
66
Usingyourmodule
Nowthatyouhaveconnectedandupdatedyourpycommoduleandinstalledalltherequired
softwareonyourcomputer,wecanbeginprogrammingyourPycommodule.
IfthisisyourfirsttimeusingaPycommodulewehighlyrecommendyoureadthroughthe
followingpages:
IntroductiontoMicroPython:ThispagewillexplainwhatMicropythonisandits
relationtoPython.
MicroPythonExamples:WealsorecommendyoubrowsetheseshortMicroPython
examplestofamiliariseyourselfwithitssyntax.Thisisnotmeantasacomprehensive
guidetoMicroPythonprogrammingbutratherareferencetothosewhoalreadyknow
programming.Ifyouarenewtopython,orprogrammingalltogether,wehighly
recommendsearchingtheinternetforPythontutorials.Therearemanyverygood
tutorialsavailableforfreeandtheskillsyoulearnwillbeeasilytransferabletoour
platform.
YourfirstPymakrproject:OnceyouunderstandwhatMicroPythonis,thisguidewill
takeyouthroughsettingupyourfirstPymakrprojecttoblinktheon-boardRGBLED.
ThisguidewillexplainthestructureofaMicroPythonprojectaswellashowtouploadit
toyourmodule.
OnceyouarefamiliarwithMicroPythonandPymakr,therecommendedwayofuploading
codetoyourmodule,youcanexplorethepagesbelow.Thesewilldiscussingreaterdetail
thevariousmechanismsforrunningcodeonyourdeviceaswellashowtorecoveritif
somethinggoeswrong.
REPL:TheREPL(ReadEvaluatePrintLoop)isaninteractiveterminalthatallowsyou
totypeinandtestyourcodedirectlyonthedevice,justlikeinteractivepython
interpreter.ItcanbeaccessedviaUARTorTelnet.Thisisaccessedeasiestbyusing
Pymakrbutifyouwishtouseothertools,thispagewillexplainhow.
FTP:AllPycommodulesstartupwithaWiFiaccesspointenabled,andasimpleFTP
serverrunningonit.OnceconnectedtotheWiFinetwork,youcanuseFTPtotransfer
filesovertoyourdevicewirelessly.Thiscanbeveryusefulifyoudonothavephysical
accesstoyourdevice.
SafeBoot:Itispossiblethatsomecodeyouuploadtoyourmodulewillpreventyou
accessingtheREPLorFTPserver,preventingyoufromupdatingyourscripts.This
guidewilldetailhowtosafebootyourmoduleandhowtoremovetheoffendingscripts
1.3Programmingthemodules
67
fromit.
1.3Programmingthemodules
68
IntroductiontoMicroPython
OurboardsworkwithMicroPython;aPython3.5implementationthatisoptimisedtorunon
microcontrollers.Thisallowsformuchfasterandmoresimpledevelopmentprocessthan
usingC.
BootingintoMicroPython
Whenbooting,twofilesareexecutedautomatically:firstboot.pyandthen main.py.These
areplacedinthe /flashfolderontheboard.Anyotherfilesorlibrariescanbeplacedhere
aswell,andcanbeincludedorusedfrom boot.pyor main.py.
Thefolderstructurein /flashlookslikethepicturebelow.Thefilescanbemanagedeither
usingFTPorusingthePymakrPlugin.
Tips&Tricks
MicropythonsharesmajorityofthesamesyntaxasPython3.5.Theintentionofthisdesign
istoprovidecompatibilityupwardsfromMicropythontoPython3.5,meaningthatcode
writtenforMicropythonshouldworkinasimilarmannerinPython3.5.Therearesomeminor
variationsandtheseshouldtakenviewedasimplementationdifferences.
1.3.1IntroductiontoMicroPython
69
MicropythonalsohasanumberofMicropythonspecificlibrariesforaccessinghardware
levelfeatures.SpecificsrelatingtothoselibrariescanbefoundintheFirmwareAPI
Referencesectionofthisdocumentation.
Micropython,unlikeC/C++orArduino,doesnotusebraces{}toindicateblocksof
codespecifiedforclassandfunctiondefinitionsorflowcontrol.Blocksofcodeare
denotedbylineindentation,whichisstrictlyenforced.
Thenumberofspacesintheindentationisvariablebutallstatementswithinablock
mustbeindentedthesameamount.
1.3.1IntroductiontoMicroPython
70
MicroPythonExamples
TogetyoustartedwithPython(MicroPython)syntax,we'veprovidedyouwithanumberof
codeexamples.
VariableAssignment
AswithPython3.5,variablescanbeassignedtoandreferenced.Belowisanexampleof
settingavariableequaltoastringandthenprintingittotheconsole.
variable="HelloWorld"
print(variable)
ConditionalStatements
Conditionalstatementsallowcontroloverwhichelementsofcoderundependingonspecific
cases.Theexamplebelowshowshowatemperaturesensormightbeimplementedincode.
temperature=15
target=10
iftemperature>target:
print("TooHigh!")
eliftemperature<target:
print("TooLow!")
else:
print("Justright!")
Loops(For&Whileloop)
Loopsareanotherimportantfeatureofanyprogramminglanguage.Thisallowsyoutocycle
yourcodeandrepeatfunctions/assignments/etc.
forloopsallowyoutocontrolhowmanytimesablockofcoderunsforwithinarange.
x=0
foryinrange(0,9):
x+=1
print(x)
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71
whileloopsaresimilarto forloops,howevertheyallowyoutorunaloopuntilaspecific
conditionalis true/false.Inthiscase,theloopchecksif xislessthan 9eachtimethe
looppasses.
x=0
whilex<9:
x+=1
print(x)
Functions
Functionsareblocksofcodethatarereferredtobyname.Datacanbepassedintoittobe
operatedon(i.e.theparameters)andcanoptionallyreturndata(thereturnvalue).Alldata
thatispassedtoafunctionisexplicitlypassed.
Thefunctionbelowtakestwonumbersandaddsthemtogether,outputtingtheresult.
defadd(number1,number2):
returnnumber1+number2
add(1,2)#expectaresultof3
Thenextfunctiontakesaninputnameandreturnsastringcontainingawelcomephrase.
defwelcome(name):
welcome_phrase="Hello,"+name+"!"
print(welcome_phrase)
welcome("Alex")#expect"Hello,Alex!"
DataStructures
Pythonhasanumberofdifferentdatastructuresforstoringandmanipulatingvariables.The
maindifference(regardingdatastructures)betweenCandPythonisthatPythonmanages
memoryforyou.Thismeansthere’snoneedtodeclarethesizesoflists,dictionaries,
strings,etc.
Lists
Adatastructurethatholdsanorderedcollection(sequence)ofitems.
1.3.2MicroPythonExamples
72
networks=['lora','sigfox','wifi','bluetooth','lte-m']
print(networks[2])#expect'wifi'
Dictionaries
Adictionaryislikeanaddress-bookwhereyoucanfindtheaddressorcontactdetailsofa
personbyknowingonlyhis/hername,i.e.keys(names)areassociatewithvalues(details).
address_book={'Alex':'2604CrosswindDrive','Joe':'1301HillviewDrive','Chris':'323
6GoldleafLane'}
print(address_book['Alex'])#expect'2604CrosswindDrive'
Tuple
Similartolistsbutareimmutable,i.e.youcannotmodifytuplesafterinstantiation.
pycom_devices=('wipy','lopy','sipy','gpy','fipy')
print(pycom_devices[0])#expect'wipy'
FormorePythonexamples,checkoutthesetutorials.Beawareoftheimplementation
differencesbetweenMicroPythonandPython3.5.
1.3.2MicroPythonExamples
73
YourFirstPymakrProject
ThisguidewilltakeyouthroughhowtosetupyourfirstprojectwithPymakrandmakethe
on-boardRGBLEDflashvariouscolours.
CreatingaprojectinPymakr
1. Firstlyyouwillneedtocreateanew,empty,directoryonyourcomputer.Forthis
examplewewillcreateonecalled RGB-Blink.
2. NextyouwillneedtoopeneitherAtomorVisualStudioCodedependingonwhichyou
setuppreviously.
3. Oncethetexteditorhasloadedyouwillneedtoclick File> Open,andopenthe
directoryyoucreatedinstep1
IfyouareusingAtom,itisimportanttocheckatthispointthatAtomhas
successfullyidentifiedtheproject.Thenameofthedirectoryyoucreatedinstep1
(RGB-Blinkinthiscase)shouldbeshowninthePymakrpanelikeso:
Ifthisisnotthecaseyoucanpress alt-ctrl-ronWindows/Linuxor ctrl-alt-
cmd-lonmacOS,inordertoreloadAtomandfixtheissue.
4. Nowthatyouhaveaprojectcreated,weneedtoaddsomefilestoit.Astandard
MicroPythonprojecthasthefollowingstructure:
RGB-Blink
|-lib
||-some_library.py
|-boot.py
|-main.py
boot.pyThisisthefirstscriptthatrunsonyourmodulewhenitturnson.Thisis
oftenusedtoconnectamoduleaaWiFinetworksothatTelnetandFTPcanbe
usedwithoutconnectingtotheWiFiAPcreatedbythemoduleandnotclutteringup
the main.pyfile.Asabeginneryoudonotneedtousea boot.py.
1.3.3YourfirstPymakrproject
74
main.pyThisscriptrunsdirectlyafter boot.pyandshouldcontainthemaincode
youwishtorunonyourdevice.
libItisoftenagoodideatosplitoutre-usablecodeintolibraries.Ifyouwantto
createoruselibrariescreatedbyothers,youwillneedtocreatea libdirectory
andputthelibraryfilesinthis.Itisimportantthatyouput .pyfilesdirectlyinto
libratherthancreatingadirectorytree.BydefaultMicroPythonwillnotdetect
anylibrarieswithinsub-directories.
Forthisexample,youwilljustneedtocreatea main.pyfile.
Nowthattheprojectstructureissetup,youmaywishtoconfigureprojectspecificsettingsfor
Pymakre.g.Whichserialporttouse.OnAtomyouneedtoclickthe ^buttononthe
Pymakrpane,thenclick ProjectSettings.OnVisualStudioCodeyouneedtoclickthe
Allcommandsbuttononthebottomofthewindows,thenclick Pymakr>ProjectSettings.
Thiscreatesafilecalled pymakr.confinsideyourprojectandpopulatesitwithdefault
settingscopiedoverfromyourglobalsettings.Adetailedexplanationofthesesettingscan
befoundhere.
Controllingtheon-boardLED
Nowthatyouhavesetupandconfiguredyourproject,wecanmoveontoprogrammingyour
module.Thefirstthingwewillneedtodoisimportsomelibrariesinordertointeractwiththe
on-boardLED.ThePycomfirmwarecomeswithalargeamountoflibrariesforstandard
functionalitybuilt-in.YoucanfindoutmoreabouttheseintheAPIdocumentation.Forthis
exampleyouwillneedtoopenthe main.pyfileandaddthefollowingcode:
importpycom
importtime
Thiswillimporttwolibraries, PycomwhichisresponsibleforPycomspecificfeatures,such
astheon-boardLEDand timewhichisastandardlibraryusedtiminganddelays.
YoumayhavenoticedthatwhenyoupowerupyourPycommodule,theon-boardLED
blinksblueonaregularbasis.This"heartbeat"isusedasawayofknowthatyourmodule
haspoweredupandstartedcorrectly.BeforewecanchangethecolourofthisLEDweneed
todisablethisheartbeat.Belowyourimportsyouwillneedtoaddthefollowing:
pycom.heartbeat(False)
1.3.3YourfirstPymakrproject
75
Nowit'stimetotestyourcode.OnthePymakrpane/bottomofthewindowyouwillseea
runbutton.(Ifyouhaven'tconnectedtoyourdeviceyet,youwillneedtodothatfirst).
Whenyouclicktherunbutton,thecodeinthecurrentlyopenfilewillbeexecutedonthe
device,butitwon'tcopyittothedevice.Afterrunningthiscode,youshouldseethatthaton-
boardLEDstopsblinkingblue.
NowthatwecanconfirmthedeviceisconnectedandPymakrisabletoruncodeonit,we
cancompleteourscripttoblinktheLEDlikeso:
importpycom
importtime
pycom.heartbeat(False)
whileTrue:
pycom.rgbled(0xFF0000)#Red
time.sleep(1)
pycom.rgbled(0x00FF00)#Green
time.sleep(1)
pycom.rgbled(0x0000FF)#Blue
time.sleep(1)
Onceyouruntheabovescript,itwillrunforever.Youwillnoticethispreventsyoufrom
accessingtheinteractiveREPLonthedevice(Youcannotseethe >>>prompt).Inorderto
stopthescript,clickontothePymakrterminal,andpress ctrl-conyourkeyboard.This
shouldstopthescriptrunningandreturnyoutotheinteractiveREPL.
Uploadingtoyourmodule
IntheprevioussectionwegotcoderunningononyourPycommoduleusingthe run
featureofPymakr.Thisisusefulforquicktestingbuthasacoupleofdrawbacks.Firstlythe
codedoesnotremainonthedevicepermanently.Ifyourebootthedevice,itwillnolonger
berunningyourcode.Secondly,itwillonlyworkifyouareusinglibrariesbuiltintothe
firmware.Ifyouneedanyextralibraries,theseneedtobecopiedtothedevicefirst.Thisis
wherethe uploadfeaturecomesin.Ifinsteadof runyouclick upload,Pymakrwill
uploadallthefilesintheproject(solongastheirtypeisinthe sync_file_typessettingfor
yourproject).Thesethenpersistonyourdeviceevenbetweenreboots,andallowsyouto
uselibrariesfromthe libfolderinyourproject.
Ifyouneedtoremovefilesfromyourdeviceyouhavetwooptions,eitherconnectviaFTP
andmanageyourfilesthatwayorformatthedevice'sinternalflashlikeso:
1.3.3YourfirstPymakrproject
76
importos
os.mkfs('/flash')
1.3.3YourfirstPymakrproject
77
REPL(ReadEvaluatePrintLoop)
REPLstandsforReadEvaluatePrintLoop,andisthenamegiventotheinteractive
MicroPythonpromptthatisaccessibleonthePycomdevices.UsingtheREPLisbyfarthe
easiestwaytotestoutPythoncodeandruncommands.YoucanusetheREPLinaddition
towritingscriptsin main.py.
ThefollowingpageswillexplainhowtousetheREPLwithbothSerialUSBandTelnet
connections.
TheREPLincludesthefollowingfeatures:
Inputhistory:usearrowupandarrowdowntoscrollthroughthehistory
Tabcompletion:presstabtoauto-completevariablesormodulenames
Haltanyexecutingcode:with Ctrl-C
Copy/pastecodeoroutput: Ctrl-Cand Ctrl-V
ThereareanumberofusefulshortcutsforinteractingwiththeMicroPythonREPL.See
belowforthekeycombinations;
Ctrl-AonablanklinewillenterrawREPLmode.Thisissimilartopermanent
pastemode,exceptthatcharactersarenotechoedback.
Ctrl-BonablanklikegoestonormalREPLmode.
Ctrl-Ccancelsanyinput,orinterruptsthecurrentlyrunningcode.
Ctrl-Donablanklinewilldoasoftreset.
Ctrl-Eenters‘pastemode’thatallowsyoutocopyandpastechunksoftext.Exit
thismodeusing Ctrl-D.
Ctrl-Fperformsa"safe-boot"ofthedevicethatprevents boot.pyand main.py
fromexecuting
1.3.4REPL
78
SerialUSBREPL(UART)
TousetheREPL,aPycomdevicemustbeconnectedtothehostcomputerwithaUSB
connectioneithertoanExpansionBoardortoserialconverter(adiagramofhowtodothis
canbefoundthethegettingstartedpageforyourmodule).
InordertoconnecttotheREPLoverUSBserial,therearemultiplemethods.Detailedbelow
aretheexplanationsofhowtodoitinMacOS,LinuxandWindows.
Allplatforms
ByfartheeasiestwaytoaccesstheUSBUARTREPLisviatheourPymakrplug-infor
AtomandVisualStudioCode.Thisaddsapanetothebottomoftheeditorsthatallowsyou
todirectlyaccesstheREPLandanyoutputfromthedevice.Detailedinstructionsonhowto
setupPymakrcanbefoundhere.
macOSandLinux
ToopenaserialUSBconnectionfrommacOS,anyserialtoolmaybeused;inthisexample,
theterminaltool screenwillbeused.
Openaterminalinstanceandrunthefollowingcommands:
$screen/dev/tty.usbmodem*115200
Uponexiting screen,press CTRL-ACTRL-\.Ifthekeyboarddoesnotsupportthe \-key
(i.e.anobscurecombinationfor \like ALT-SHIFT-7isrequired),thekeycombinationcan
beremappedforthe quitcommand:
create ~/.screenrc
addbind qtothe exitcommand
Thiswillallowscreentoexitedbypressing CTRL-AQ.
OnLinux, picocomor minicommaybeusedinsteadof screen.Theusbserial
addressmightalsobelistedas /dev/ttyUSB01orahigherincrementfor ttyUSB.
Additionally,theelevatedpermissionstoaccessthedevice(e.g.groupuucp/dialoutor
use sudo)mayberequired.
1.3.4.1SerialUSB
79
Windows
AterminalemulatorisneededtoopentheconnectionfromWindows;theeasiestoptionisto
downloadthefreeprogram,PuTTY.
COMPort
TousePuTTYtheserialport(COMport)inwhichthePycomdeviceisconnected,mustbe
located.InWindows,thisinformationcanbefoundfromthe'DeviceManager'program.
1. OpentheWindowsstartmenuandsearchfor'DeviceManager'
2. TheCOMportforthePycomdevicewillbelistedas'USBSerialDevice'orasimilar
name
3. Copy/WritedowntheassociatedCOMport(e.g. COM4)
UsingPutty
1. WithPuTTYopen,clickon Sessionintheleft-handpanel
2. Nextclickthe SerialradiobuttonontherightandentertheassociatedCOMport(e.g.
COM4)inthe SerialLinebox
3. Finally,clickthe Openbutton
1.3.4.1SerialUSB
80
TelnetREPL
Pycomdevicesalsosupportaconnectionvia telnet,usingthedevice'sonboard
WiFi/WLAN.Connecttothedevice'sWiFiAccessPoint(AP)andusingthefollowing
credentialstoconnecttotheAP.TheWiFi SSIDwillappearuponpoweringonaPycom
Deviceforthefirsttime(e.g. lopy-).Tore-enablethisfeatureatalaterdate,pleasesee
network.WLAN.
password: www.pycom.io
TelnetServer
Additionally,tousetheMircoPythonREPLovertelnet,furtherauthenticationisrequired.The
defaultcredentialsforthetelnetserverare:
username: micro
password: python
Seenetwork.serverforinfoonhowtochangethedefaultauthentication.
Allplatforms
ByfartheeasiestwaytoaccesstheTelnetREPLisviatheourPymakrplug-inforAtomand
VisualStudioCode.Thisaddsapanetothebottomoftheeditorsthatallowsyoutodirectly
accesstheREPLandanyoutputfromthedevice.Detailedinstructionsonhowtosetup
Pymakrcanbefoundhere.
macOSandLinux
OncethehostmachineisconnectedtothePycomdevice'sAccessPoint,atelnet
connectionmaybeopenedfromaterminalinstance.
$telnet192.168.4.1
Uponconnection,thetelnetprogramwillpromptforthe usernameand passwordinthe
sectionabove.
Windows
1.3.4.2Telnet
81
AterminalemulatorisneededtoopenatelnetconnectionfromWindows;theeasiestoption
istodownloadthefreeprogram,PuTTY.
1. WithPuTTYopen,selecttelnetasconnectiontypeandleavethedefaultport( 23)
2. NextentertheIPaddressofthePycomdevice(e.g. 192.168.4.1)
3. Finallyclick Open
WhenusingaPycomdevicewithapersonal,homeorofficeWiFiaccesspoint,the
telnetconnectionmaystillbeused.Inthisinstance,theuserwillneedtodeterminethe
Pycomdevice'slocalIPaddressandsubstitutethisfor 192.168.4.1,referredtointhe
earliersections.
1.3.4.2Telnet
82
FTP(LocalFileSystem)
ThereisasmallinternalfilesystemaccessiblewitheachPycomdevice,called /flash.
Thisisstoredwithintheexternalserialflashmemory.IfamicroSDcardisalsoconnected
andmounted,itwillbeavailableaswell.Whenthedevicestartsup,itwillalwaysbootfrom
the boot.pylocatedinthe /flashfilesystem.
ThefilesystemisaccessibleviathenativeFTPserverrunningoneachPycomdevice.
OpenanFTPclientandconnectto:
url: ftp://192.168.4.1
username: micro
password: python
Seenetwork.serverforinformationonhowtochangethedefaults.Therecommendedclients
are:
macOS/Linux:defaultFTPclient
Windows:FilezillaandFireFTP
Forexample,fromamacOS/Linuxterminal:
$ftp192.168.4.1
TheFTPserverdoesn’tsupportactivemode,onlypassivemode.Therefore,ifusingthe
nativeunixFTPclient,immediatelyafterloggingin,runthefollowingcommand:
ftp>passive
TheFTPserveronlysupportsoneconnectionatatime.IfusingotherFTPclients,please
checktheirdocumentationforhowtolimitthemaximumallowedconnectionstooneata
time.
FileZilla
IfusingFileZilla,it'simportanttoconfigurethesettingscorrectly.
Donotusethequickconnectbutton.Instead,openthesitemanagerandcreateanew
configuration.Withinthe Generaltab,ensurethatencryptionissetto: OnlyuseplainFTP
(insecure).
1.3.5FTP
83
Inthe TransferSettingstab,limitthemaxnumberofconnectionstoone.OtherFTPclients
maybehaveinasimilarways;visittheirdocumentationformorespecificinformation.
1.3.5FTP
84
BootModes
Ifpoweringupnormallyoruponpressingtheresetbutton,aPycommodulewillbootinto
standardmode;the boot.pyfilewillbeexecutedfirst,followedby main.py.Itispossibleto
alterthebootprocedureofthemodulebytyingcertainpins highor lowwhenthemodule
boots.
Bootloader
Ifyouupdatedyourdevicebeforeusingit,youhavealreadyputthedeviceintobootloader
mode.Thisisachievedbyconnecting G23to GNDwhilethedeviceboots.Ifyouuseda
Pysense/Pytracktoupdate,itdidthisautomaticallyforyou.Youonlyneedtoputyour
Pycommoduleintobootloadermodeifyouareupdatingitsfirmware,orareprogramming
yourownlowlevelcode.ThisisnotrequiredifyouareupdatingyourMicroPythoncode.
SafeBoot
SometimesthecodeyouhavewrittenwillpreventyougainingaccesstotheREPLor
preventyouupdatingyourcode.Someexamplemaybe:
YoudisabledtheWiFi/UART
YourcodegetsstuckbeforereachingtheREPL
Yousetasocketasblockingbutneverreceiveanydata
Inordertofixthisyoucansafebootyourmodule.Thiswillprevent boot.pyand main.py
frombeingexecutedandwilldropyoustraightintotheinteractiveREPL.Afterreset,if P12
pinisheld high(i.e.connectittothe 3V3outputpin),theheartbeatLEDwillbegin
flashingorangeslowly.Ifafter3secondsthepinisstillheldhigh,theLEDwillstartblinking
faster.Inthismodethemodulewilldothesameaspreviouslyexplainedbutitwillalsoselect
thepreviousOTAimagetobootifyouhaveupdatedthemoduleviatheOTAupdate
procedure(updatesperformedviathefirmwareupdatetooldonotcount).Thisisusefulif
youflashedaOTAupdatethatbreaksthedevice.
Pin P12releasedduring:
1st3secswindow 2nd3secswindow
Disable boot.pyand main.py sameaspreviousbutusingpreviousOTAfirmware
Theselectionmadeduringsafebootisnotpersistent,thereforeafterthenextnormalreset,
thelatestfirmwarewillproceedtorunagain.
1.3.6Safeboot
85
Ifproblemsoccurwithinthefilesystemoryouwishtofactoryresetyourmoduletoremove
yourcode,runfollowingcodeintheREPL:
>>>importos
>>>os.mkfs('/flash')
Beaware,resettingtheflashfilesystemwilldeleteallfilesinsidetheinternaldevice
storage(nottheSDcard)andtheycannotberecovered.
Reset
Pycomdevicessupportbothsoftandhardresets.Asoftresetclearsthestateofthe
MicroPythonvirtualmachinebutleaveshardwareperipheralsunaffected.Todoasoftreset,
press Ctrl+DontheREPLorfromwithinascript,run:
>>>importsys
>>>sys.exit()
Ahardresetisthesameasperformingapowercycletothedevice.Inordertohardreset
thedevice,pressthe resetswitchorrun:
>>>importmachine
>>>machine.reset()
1.3.6Safeboot
86
RegisteringaPycomDevice
Someofourdevicesrequireregistrationbeforeyoucanutilisespecificfeaturessuchas
certaintypesofnetworking.Pleaseseethelistbelowforsetupguidestoensurethatyour
deviceisregisteredandactivatedonthevariousplatformsrequiredtoaccessallofthe
availablefeatures.
NotallPycomdevicesrequireactivation;mostfeaturesworkimmediatelyoutofthe
box!
1.4DeviceRegistration
87
RegisteringwithSigfox
ToensurethedevicehasbeenprovisionedwithDeviceIDandPACnumber,pleaseupdate
tothelatestfirmware.
InordertosendaSigfoxmessage,thedeviceneedtoregisterwiththeSigfoxBackend.
Navigatetohttps://backend.sigfox.com/activatetofindthelistofSigfoxenabled
developmentkits.
Select Pycomtoproceed.
NextchooseaSigfoxOperatorforthecountrywherethedevicewillbeactivated.Findthe
specificcountryandselecttheoperatortocontinue.
1.4.1Sigfox
88
Nowneedtoenterthedevice'sDeviceIDandPACnumber.
TheDeviceIDandPACnumberareretrievablethroughacoupleofcommandsviathe
REPL.
fromnetworkimportSigfox
importbinascii
#initaliseSigfoxforRCZ1(YoumayneedadifferentRCZRegion)
sigfox=Sigfox(mode=Sigfox.SIGFOX,rcz=Sigfox.RCZ1)
#printSigfoxDeviceID
print(binascii.hexlify(sigfox.id()))
#printSigfoxPACnumber
print(binascii.hexlify(sigfox.pac()))
See SigfoxformoreinfoabouttheSigfoxClassandwhichRCZregiontouse.
1.4.1Sigfox
89
Oncethedevice'sDeviceIDandPACnumberhavebeenentered,createanaccount.
Providetherequiredinformationincludingemailaddressandclicktocontinue.
AnemailconfirmingthecreationofaSigfoxBackendaccountandthesuccessful
registrationofthedeviceshouldarriveattheusersinbox.
1.4.1Sigfox
90
Cellularregistration
InordertouseyourGPy/FiPyonacellularnetworkyouarerequiredtogetaSIMcardfrom
alocalprovider.Note:ThismightdifferfromastandardSIMyoucanbuyinastore,our
devicesdonotsupportstandardLTE.
CurrentlywearenotabletoprovideanyspecificdetailsabouthowtogetsuchaSIMcard
andhowtoregisteritasmostdeploymentsareclosedtrials,eachcarrierhasit’sownrules
(forexample,whethertheyrequirespecialSIMsornot).
WerecommendcontactingyourlocalcellularproviderstochecktheirplanssurroundingLTE
CAT-M1andNB-IoT.Bycontactingthem,youwillshowthecarriersthatthereislocal
interestindeployingsuchnetworks.
Youcanfindamapofdeployednetworksandopenlabshere.
1.4.2Cellular
91
LoRaWANRegistration
RawLoRa
WhenusingrawLoRa,youdonothavetoregisteryourmoduleinanyway.Themodules
cantalktoeachotherdirectly.
LoRaWAN
InordertoconnectyourLoRacapablePycommoduletoaLoRaWANnetworkyouwillhave
toregisteryourdevicewiththedesirednetwork.Weareunabletoprovideinstructionsforall
LoRaWANnetworksbutbelowyouwillfindsomegenericinstructions,alongwithlinkstoany
specificguidesweareawareof.
Genericinstructions
Firstlyyouwillneedtogetyourmodules DeviceEUI,thiscanbeachievedusingthe
followingcode:
fromnetworkimportLoRa
importubinascii
lora=LoRa(mode=LoRa.LORAWAN)
print(ubinascii.hexlify(lora.mac()).upper().decode('utf-8'))
Theoutputwillbeahexstringlike: 70B3D5499585FCA1.Onceyouhavethisyouwillneedto
provideittoyourLoRaWANnetworkwhichwillthenprovideyouwiththedetailsneedto
connectviaOver-the-AirActivation(OTAA)orActivationbyPersonalisation(ABP)
OTAA
IfyouwishtoconnectviaOTAA(whichistherecommendedmethod)thenetworkwill
provideyouwithan ApplicationEUIand ApplicationKey.Theformeridentifieswhat
applicationyourdeviceisconnectingto,thelatterisasharedsecretkeyuniquetoyour
devicetogeneratethesessionkeysthatproveitsidentitytothenetwork.Onceyouhave
theseyoucanusetheLoRaWANOTAAexamplecodetoconnecttothenetwork.
ABP
1.4.3LoRaWAN
92
WithABPtheencryptionkeysenablingcommunicationwiththenetworkarepreconfiguredin
thedevice.Thenetworkwillneedtoprovideyouwitha DeviceAddress, NetworkSession
Keyand ApplicationSessionKey.OnceyouhavetheseyoucanusetheLoRaWANABP
examplecodetoconnecttothenetwork.
Networks
1.4.3LoRaWAN
93
IfyoucannotfindyourfavouriteLoRaWANnetworkinthelistabove,pleaseconsider
writingatutorialforhowtoconnectaPycommodulewithitandcontributeittothis
documentationviaaGitHubpullrequest.
1.4.3LoRaWAN
94
TheThingsNetwork
InordertouseTheThingsNetwork(TTN)youshouldnavigatetotheirwebsiteand
create/registeranaccount.Enterausernameandanemailaddresstoverifywiththeir
platform.
Onceanaccounthasbeenregistered,youcanregisteryourPycommoduleaseitheranode
oranano-gateway.Thestepsbelowwilldetailhowtodothis.
Createanapplication
Inordertoregisteryourdevicetoconnecttothethingsnetwork,youmustfirstcreatean
applicationforthesedevicestobelongto.ThiswaytheNetworkwillknowwheretosendthe
devicesdatato.
1.4.3.2TheThingsNetwork
95
Selectingthe ApplicationstabatthetopoftheTTNconsole,willbringupascreenfor
registeringapplications.Clickregisterandanewpage,similartotheonebelow,willopen.
Enteraunique ApplicationIDaswellasaDescription&HandlerRegistration.
NowthePycommodulenodescanberegisteredtosenddatauptothenewApplication.
RegisteraDevice
Toconnectnodestoathingsnetworkgateway,devicesneedtobeaddedtotheapplication.
Todothis,navigatetothe Devicestabonthe Applicationhomepageandclickthe
RegisterDevicebutton.
Inthe RegisterDevicepanel,completetheformsforthe DeviceIDandthe DeviceEUI.
The DeviceIDisuserspecifiedandisuniquetothedeviceinthisapplication.The Device
EUIshouldbeagloballyuniqueidentifierforthedevice.Youcanrunthefollowingonyou
PycommoduletoretrieveitsEUI.
1.4.3.2TheThingsNetwork
96
fromnetworkimportLoRa
importubinascii
lora=LoRa()
print("DevEUI:%s"%(ubinascii.hexlify(lora.mac()).decode('ascii')))
Oncethedevicehasbeenadded,changethe ActivationMethodbetween OTAAand ABP
dependingonuserpreference.Thisoptioncanbefoundunderthe Settingstab.
RegisteraNano-Gateway
YoucanalsosetupyourPycommoduletoactasagatewaywithTheThingsNetwork.The
coderequiredtodothiscanbefoundhere.
InsidetheTTNConsole,therearetwooptions, Applicationsand Gateways.Select
Gatewaysandthenclickon registerGateway.Thiswillallowforthesetupandregistration
ofanewnano-gateway.
OntheRegisterGatewaypage,youwillneedtosetthefollowingsettings:
1.4.3.2TheThingsNetwork
97
Theseareuniquetoeachgateway,locationandcountryspecificfrequency.Pleaseverify
thatcorrectsettingsareselectedotherwisethegatewaywillnotconnecttoTTN.
Youneedtotickthe"I'musingthelegacypacketforwarder"toenabletheright
settings.ThisisbecausetheNano-Gatewayusesthe'defacto'standardSemtechUDP
protocol.
Option Value
Protocol PacketForwarder
GatewayEUI UserDefined(mustmatch config.py)
Description UserDefined
FrequencyPlan SelectCountry(e.g.EU-868MHz)
Location UserDefined
AntennaPlacement IndoororOutdoor
MostLoRaWANnetworkserversexpectaGatewayIDintheformofaunique64-bit
hexadecimalnumber(calledaEUI-64).TherecommendedpracticeistoproducethisID
fromyourboardbyexpandingtheWiFiMACaddress(a48-bitnumber,calledMAC-48).You
canobtainthatbyrunningthiscodepriortoconfiguration:
1.4.3.2TheThingsNetwork
98
fromnetworkimportWLAN
importbinascii
wl=WLAN()
binascii.hexlify(wl.mac())[:6]+'FFFE'+binascii.hexlify(wl.mac())[6:]
Oncethesesettingshavebeenapplied,click RegisterGateway.AGatewayOverviewpage
willappear,withtheconfigurationsettingsshowing.Nextclickonthe GatewaySettingsand
configuretheRouteraddresstomatchthatofthegateway(default:
router.eu.thethings.network).
The Gatewayshouldnowbeconfigured.
1.4.3.2TheThingsNetwork
99
ConnectingtoObjeniousLoRaWAN'Spot'
network
Identifiers
ToconnectaPycomLoRadevice(LoPy,LoPy4,FiPy)toObjeniousyou'llneedtoprovision
it.Thisrequiresthreepiecesofinformation
DeviceEUI(DevEUI)
ApplicationEUI(AppEUI)
ApplicationKey(AppKey)
DeviceEUI
Thiscomesfromthedeviceitselfandcanbeobtainedfrom lora.mac().
Toobtaintherequiredhexadecimalrepresentationyoucanrunthefollowingcodeonyour
LoPy:
fromnetworkimportLoRa
importubinascii
lora=LoRa()
print("DevEUI:%s"%(ubinascii.hexlify(lora.mac()).decode('ascii')))
ApplicationEUIandApplicationKey
ApplicationEUIandKeyaretwoLoRaWANparametersthatshouldideallybygeneratedby
you,ifsupplyingdevicestoendcustomers.
TheApplicationEUIisaEUI-64(8bytes)identifierwhichshouldbeuniversallyunique-it's
usuallyallocatedfromaMA-SblockpurchasedfromtheIEEERegistrationAuthority.
TheApplicationKeyshouldbearandomlygenerated,secure,128bit(16byte)token.
FortestingpurposesweprovideascriptwhichgeneratesarandomApplicationEUIfromour
assignmentandaseriesofApplicationKeys:
EUI/Keygeneratorfortesting
(note:theApplicationEUIproducedbythisscriptisnotguaranteedtobeunique)
1.4.3.2Objenious
100
TousethescriptmakesureyouareusingPython3.6onyourcomputerandrunit(onyour
computer,notonthePycomboard)as:
pythongenerate_keys.py1
Theoutputwillbesimilarto:
AppEUI:70b3d54923e36a89
AppKeys:
78fe712d96f46784a98b574a8cd616fe
IfyouareregisteringmultipledevicesyoucangeneratemoreApplicationsKeysbychanging
1toyourdesirednumberofdevices.
Provisioning
Onceyouhavethethreeidentifiersforyourdeviceyouneedtoregisterthemonthe
Objeniusportal.
Follow"Importerdescapteurs"under"StatucdoParc"andselect"ProvisioningUnitaire":
OncetheregiveyourdeviceanameandentertheDevEUI,AppEUIandAppKeyobtained
fromthestepsabove:
1.4.3.2Objenious
101
1.4.3.2Objenious
102
PymakrPlugins
TomakeitaseasyaspossiblePycomhasdevelopedapluginfortwopopulartexteditors,
calledPymakr.Thesepluginshavebeenbuiltandareavailableforthefollowingplatforms:
2.1Installation
103
2.1Installation
104
PymakrPluginInstallationforAtom
Forbeginners,usersgettingstartedwithMicroPython&PycomaswellasAtomtexteditor
users,werecommendthePymakrPluginforAtom.Thissectionwillhelpyougetstarted
usingtheAtomTextEditor&PymakrPlugin.
PleasefollowthesestepstoinstallthePymakrPlugin:
1. EnsurethatyouhaveAtominstalledandopen.
2. NavigatetotheInstallpage,via Atom>Preferences>Install
2.1.1Atom
105
3. Searchfor PymakrandselecttheofficialPycomPymakrPlugin.
4. YoushouldnowseeandclicktheInstallbutton.Thiswilldownloadandinstallthe
PymakrPlugin.
5. That’sit!You’veinstalledthePymakrPluginforAtom.
2.1.1Atom
106
ConnectingviaSerialUSB
AfterinstallingthePymakrPlugin,youneedtotakeafewsecondstoconfigureitforfirst
timeuse.Pleasefollowthesesteps:
1. ConnectyourPycomdevicetoyourcomputerviaUSB.IfyouareusinganExpansion
Board2.0,andhavejustfinishedafirmwareupgrade,besuretoremovethewire
betweenGNDandG23andresetyourdevicebypressingthebutton.Note:youdon't
needthewireforExpansionBoard3.0
2. OpenAtomandensurethatthePymakrPluginhascorrectlyinstalled.
3. OpenthePymakrconsolebyclickingthe ^button,locatedinthelowerrightsideof
theAtomwindow.
4. Click, Morefollowedby GetSerialPorts.Thiswillcopytheserialaddressofyour
expansionboardtoyourclipboard.
2.1.1Atom
107
5. Navigateto Settings>GlobalSettings
6. Pastetheserialaddressyoucopiedearlierintothetextfield DeviceAddress
7. PressconnectandthePymakrconsoleshouldshowthreearrows >>>,indicatingthat
youareconnected
2.1.1Atom
108
Thesesettingscanalsobeappliedonaperprojectbasisbyclicking Settingsthen
ProjectSettings.ThiswillopenaJSONfilewhichyoucanedittoenteryourdesired
settings.
ThisprocessiseasiestwitheitheraPycomExpansionBoardoraPytrack/Pysenseas
theaddressesareautomaticallyselected.ForexternalproductssuchasFTDIUSB
SerialCables,theserialaddressmayneedtobecopiedmanually.Additionally,thereset
buttononthedevicemayalsoneedtobepressedbeforeaconnectionmessage
appears.
ConnectingviaTelnet
AfterinstallingthePymakrPlugin,adevicemaybeconnectedviathetelnetinterface.
Pleaseseethefollowingsteps:
1. EnsurethatPycomdeviceisturnedon
2. ConnectthehostcomputertotheWiFiAccessPointnamedafteryourboard(theSSID
willbeasfollowse.g. lopy-wlan-xxxx, wipy-wlan-xxxx,etc.).Thepasswordis
www.pycom.io.
3. Followthestepsasaboveinthe"ConnectingviaSerialUSB"sectionbutenter
192.168.4.1astheaddress.
4. Thedefaultusernameandpasswordare microand python,respectively.
5. Click ConnectinthePymakrpane,Pymakrwillnowconnectviatelnet.
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2.1.1Atom
110
PymakrPluginInstallationforVisual
StudioCode
PycomalsosupportsMicrosoft'sVisualStudioCodeIDEplatformwiththePymakrPlugin.To
downloadVisualStudioCode,navigatetoVSCode.
YouwillalsoneedNodeJSinstalledonyourPC.PleasedownloadthelatestLTSversion
availablefromtheNodeJSwebsite.
PleasefollowthesestepstoinstallthePymakrVSCodeExtension:
1. EnsurethatyouhaveVSCodeinstalledandopen.
2. NavigatetotheExtensionspage,usingthe5thbuttonintheleftnavigation
3. Searchfor Pymakrandclicktheinstallbuttonnexttoit.
2.1.2VisualStudioCode
111
4. Withinafewminutes,areloadbuttonshouldappear.PressittoreloadVSCode.
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112
5. That’sit!You’veinstalledthePymakrExtensionforVSCode
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113
ConnectingviaSerialUSB
AfterinstallingthePymakrPlugin,youneedtotakeafewsecondstoconfigureitforfirst
timeuse.Pleasefollowthesesteps:
1. ConnectyourPycomdevicetoyourcomputerviaUSB.Ifyouareusinganexpansion
board,andhavejustfinishedafirmwareupgrade,besuretoRemovethewire
betweenGNDandG23andresetyourdevicebypressingthebutton.
2. OpenVisualStudioCodeandensurethatthePymakrPluginhascorrectlyinstalled.
3. Click AllcommandsonthebottomoftheVisualStudioCodewindow
4. Inthelistthatappears,click Pymakr>Extra>ListSerialPorts
5. Thiswilllisttheavailableserialports.IfPymakrisabletoauto-detectwhichtouse,this
willbecopiedtoyourclipboard.Ifnotpleasemanuallycopythecorrectserialport.
6. Onceagainclick Allcommands,thenclick Pymakr>GlobalSettings.Thiswillopena
JSONfile.Pastetheserialaddressyoucopiedearlierintothefield addressandsave
thefile.
2.1.2VisualStudioCode
114
7. FinallyclosetheJSONfile,click Allcommands,then Pymakr>Connecttoconnectyour
device.ThePymakrconsoleshouldshowthreearrows >>>,indicatingthatyouare
connected
Thesesettingscanalsobeappliedonaperprojectbasisbyclicking Allcommandsthen
Pymakr>ProjectSettings.ThiswillopenaJSONfilewhichyoucanedittoenteryour
desiredsettingsforthecurrentlyopenproject.
ThisprocessiseasiestwitheitheraPycomExpansionBoardoraPytrack/Pysenseas
theaddressesareautomaticallyselected.ForexternalproductssuchasFTDIUSB
SerialCables,theserialaddressmayneedtobecopiedmanually.Additionally,thereset
buttononthedevicemayalsoneedtobepressedbeforeaconnectionmessage
appears.
ConnectingviaTelnet
AfterinstallingthePymakrPlugin,adevicemaybeconnectedviathetelnetinterface.
Pleaseseethefollowingsteps:
1. EnsurethatPycomdeviceisturnedon
2. ConnectthehostcomputertotheWiFiAccessPointnamedafteryourboard(theSSID
willbeasfollowse.g. lopy-wlan-xxxx, wipy-wlan-xxxx,etc.).Thepasswordis
www.pycom.io.
3. Followthestepsasaboveinthe"ConnectingviaSerialUSB"sectionbutenter
192.168.4.1astheaddress.
2.1.2VisualStudioCode
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4. Thedefaultusernameandpasswordare microand python,respectively.
5. FinallyclosetheJSONfile,click Allcommands,then Pymakr>Connect,Pymakrwill
nowconnectviatelnet.
2.1.2VisualStudioCode
116
ToolsandFeatures
Console(REPL)
MicroPythonhasaninteractivecodetoolknownastheREPL(ReadEvaluatePrintLine).
TheREPLallowsyoutoruncodeonyourdevice,linebyline.Tobegincoding,gotothe
PymakrPluginConsoleandstarttypingyourcode.StartbymakingtheLEDchangecolour.
importpycom#weneedthismoduletocontroltheLED
pycom.heartbeat(False)#disabletheblueblinking
pycom.rgbled(0x00ff00)#maketheLEDlightupgreenincolour
YoucanchangethecolourbyadjustingthehexRGBvalue.
pycom.rgbled(0xff0000)#nowmaketheLEDlightupredincolour
Theconsolecanbeusedtorunanypythoncode,alsofunctionsorloops.
Use print()tooutputcontentsofvariablestotheconsoleforyoutoread.Returnedvalues
fromfunctionswillalsobedisplayediftheyarenotcaughtinavariable.Thiswillnothappen
forcoderunningfromthemainorbootfiles.Hereyouneedtouse print()tooutputtothe
console.
Notethatafterwritingorpastinganyindentedcodelikeafunctionorawhileloop,the
userwillhavetopressenteruptothreetimestotellMicroPythonthecodeistobe
closed(thisisstandardMicroPython&Pythonbehaviour).
AlsobeawarethatcodewrittenintotheREPLisnotsavedafterthedeviceispowered
off/onagain.
Run
Totestcodeonadevice,createanew .pyfileoropenanexistingone,typethedesired
code,savethefileandthenpressthe Runbutton.Thiswillrunthecodedirectlyontothe
PycomboardandoutputtheresultsofthescripttotheREPL.
2.2Tools/Features
117
Changesmadetofileswon’tbeautomaticallyuploadedtotheboarduponrestartingor
exitingthe Runfeature,asthePycomboardwillnotstorethiscode.Inordertopush
thecodepermanentlytoadevice,usethe Uploadfeature.
Projects
PymakrPluginsupportsuserprojects,allowingforpre-configuredsettingssuchasdefault
serialaddress/credentials,filestobeignoredandfolderstosync.
pymakr.conf
PymakrPluginsupportslocalprojectsettingsusingafilecalled pymakr.conf.Thiscanbe
usedtostorethedefaultserialaddressofadevice,whichfilestoignoreandothersettings.
Anexample pymakr.confisshownbelow:
{
"address":"/dev/cu.usbserial-AB001234",
"username":"micro",
"password":"python",
"sync_folder":"scripts"
}
Upload
ThePymakrPluginshaveafeaturetosyncanduploadcodetoadevice.Thiscanbeused
forbothuploadingcodetoadeviceaswellastestingoutscriptsbyrunningthemliveonthe
device.Thefollowingstepsdemonstratehowtousethisfeature.
Tostartusingthe Uploadfeature,ensurethataprojectfolderhasbeencreatedforthe
device.Forexample,ifusingthe pymakr.conffromabove,thisprojectfoldershouldbe
named scripts.Thisfoldershouldhavethefollowingstructure:
Libraryfilesshouldbeplacedintothe libfolder,certificatesintothe certfolderandso
on.The Uploadbuttonwilltakethehighestlevelfolder(currentlyopen)anduploadthisto
theconnectedPycomdevice.Thefileswillbepushedtothedeviceinexactlythesame
2.2Tools/Features
118
structureaswithinthecodeeditor'sfiledirectory.
More
Clickingthe MorebuttonwithinthePymakrPluginallowsforsomeadditionalfeatures.See
theoptionsbelowforspecificfunctionality.
GetFirmwareVersion
RetrievesthefirmwareversionofthePycomdeviceconnectedtothePymakrPlugin
instance.
GetWiFiAPSSID
RetrievesthedefaultWiFiAccessPointSSIDofthePycomdeviceconnectedtothePymakr
Plugininstance.
GetSerialPorts
RetrievesthevariousserialportsthatareavailabletothePymakrPlugininstance.
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119
Pymakrsettings
BelowyouwillfindadescriptionofthevarioussettingsavailableforPymakr.
address
ThisistheaddressofthePycommoduleyouwantPymakrcanconnectto.Thiscanbe
eitheraserialport(e.g COM1onwindowsor /dev/cu.usbserial-DQ0054ESonLinux/macOS)
oranIPaddress(Telnet)(e.g. 192.168.4.1ifconnectedtotheAPcreatedbythePycom
module).
username
IfaIPaddresswasprovidedforthe addressthereforePymakrisconnectingviaTelnet,you
willalsoneedtoprovideausername,thedefaultis micro.
password
IfanIPaddresswasprovidedfortheaddress,PymakrisconnectingviaTelnet.Youwillalso
needtoprovideapassword,thedefaultis python.
sync_folder
Ifleftblank,alldirectoriesinsidetheprojectwillbesyncedtothedevicewhentheuserclicks
upload.Ifdirectoriesarespecified,onlythesedirectorieswillbesynced,allotherswillbe
ignored
open_on_start
Ifsetto true,thePymakrconsolewillopenandtrytoconnectwhentheeditorisstarted,or
aprojectisopened.
safe_boot_on_upload
2.3Settings
120
Ifsetto true,Pymakrwillreboottheconnecteddeviceintosafe-modebeforeuploading.
ThisisusefulifyourcodeusesalotofRAMcausingissueswiththeuploadprocedure.
Thisfeatureisonlyavailableonmodulesrunningfirmwareversion 1.17.0.b1orhigher.
sync_file_types
Onlyfilesendingwiththeextensionslistedinthissettingwillbesyncedtothedevicewhen
performinganupload.Allotherfilesareignored.Bydefaultthisissettoinclude: py,txt,
log,json,xml
ctrl_c_on_connect
Ifsetto true,Pymakrwillsentthe ctrl-csignaltotheconnectedmodulebefore
uploading.Thisshouldstopthescriptcurrentlyrunningonthedeviceandimprovethe
reliabilityoftheuploadprocess.
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Pytrack&Pysense
InadditiontotheExpansionBoard,Pycomalsoofferstwoadditionalsensorboards,which
areidealforquicklybuildingafullyfunctioningIoTsolution!Whethertheapplicationis
environmentsensingorassettracking,theseadditionalboardssupportavarietyofsensors.
Pytrack
PytrackisalocationenabledversionoftheExpansionBoard,intendedforuseinGPS
applicationssuchasassettrackingormonitoring.
Features&Hardware
ThePytrackishasanumberoffeaturesincludingGPS,3-AxisAccelerometerandBattery
Charger.Seethelistbelowfordetailedspecificsabouteachsensor,includingdatasheets.
SerialUSB
3-AxisAccelerometer(LIS2HH12)
BatteryCharger(BQ24040withJSTconnector)
GPSandGLONASS(L76-L)
MicroSDCardReader
AlloftheincludedsensorsareconnectedtothePycomdeviceviatheI2Cinterface.These
pinsarelocatedatP22(SDA)andP21(SCL).
Pysense
3.1Introduction
122
PysenseisasensorpackedversionoftheExpansionBoard,intendedforusein
environmentsensingapplicationssuchastemperature,humiditymonitoring,andlight
sensing.
Features&Hardware
ThePysenseispackedwithanumberofsensorsandhardware,seethelistbelowfor
detailedspecificsabouteachsensor,includingdatasheets.
SerialUSB
3-AxisAccelerometer(LIS2HH12)
BatteryCharger(BQ24040withJSTconnector)
DigitalAmbientLightSensor(LTR-329ALS-01)
HumidityandTemperatureSensor(SI7006-A20)
BarometricPressureSensorwithAltimeter(MPL3115A2)
MicroSDCardReader
AlloftheincludedsensorsareconnectedtothePycomdeviceviatheI2Cinterface.These
pinsarelocatedat GPI09(SDA)and GPI08(SCL).
3.1Introduction
123
InstallingSoftware
Asthedevelopmentforthesedevicesareongoingwithadditionalfeaturesbeingadded,
everyweek,itisessentialtoensureyoufrequentlycheckforupdatesonthe
Pytrack/Pysense.Aswellasupdatingthedevicefirmware,itisimportanttocheckthe
GitHubrepositoryfortherespectivelibraryfilesastheyasalsobeingupdated,toinclude
additionalfeatures/functionality.
3.2InstallingSoftware
124
UpdatingFirmware
ToupdatethefirmwareonthePysense/Pytrack/Pyscan/ExpansionBoardv3,pleaseseethe
followinginstructions.ThefirmwareofPysense/Pytrack/Pyscan/ExpansionBoardv3canbe
updatedviatheUSBportusingtheterminaltool, DFU-util.
ThelatestfirmwareDFUfilecanbedownloadedfromthelinksbelow:
PytrackDFU
PysenseDFU
ExpansionBoardDFU
Whileinthenormal,applicationmode,thePysense/Pytrack/Pyscan/ExpansionBoardv3
requireaSerialUSBCDCdriver,inDFU,bootloadermode,theDFUdriverisrequired.
Below,theUSBProductIDisdepictedforeachcase.
Board DFUbootloader(update
mode)
Applicationfirmware(normal
mode)
Pytrack 0xF014 0xF013
Pysense 0xF011 0xF012
Pyscan 0xEF37 0xEF38
ExpansionBoard
v3 0xEF99 0xEF98
Note:USBVendorIDisalways 0x04D8.
InstallingtheDFU-utilTools
macOS
Ifusing homebrew:
$brewinstalldfu-util
Ifusing MacPorts:
portinstalllibusbdfu-util
Linux
3.2.1UpdatingFirmware
125
UbuntuorDebian:
$sudoapt-getinstalldfu-util
Fedora:
$sudoyuminstalldfu-util
Arch:
$sudopacman-Sydfu-util
Windows
DFU-utilv0.9–TooltouploadthefirmwaretothePytrack/Pysense
Zadig–InstallertoolforthePytrack/PysenseboardDFUFirmware
TouploadedthelatestDFUfirmwaretothePytrack/Pysense,firstinstalltheDFUdrivers
tothehostcomputer.OpenZadigandselect libusbKasthedriver.
Toinstallthedrivers,thePytrack/PysenseboardmustbeinDFU-mode:
1. DisconnecttheUSBcable
2. Holddownthebuttonontheshield
3. ConnecttheUSBcable
4. Keepthebuttonpressedforatleastonesecond
5. Releasethebutton.WhentheboardisconnectedinDFU-mode,itwillbeinthisstate
for7seconds.
6. Clickthe “InstallDriverbuttonimmediately.Ifthedriverwasunsuccessful,repeat
fromstep1.
HeretheUSBIDhastobetheDFU-bootloaderone( 0xF014forPytrackor 0xF011
forPysense).
ThisisasuccessfulDFUdriverinstallationforPytrack:
3.2.1UpdatingFirmware
126
OpenthecommandpromptandnavigatetothedirectorywheretheDFU-utilandthe
firmwarewasdownloaded(mustbeinsamedirectory).Repeattheproceduretogetthe
boardinDFU-modeandrunthecommandbelowbutreplace X.X.Xwiththefirmware
versionandreplacePysensewithPytrackifitisthePytrackthatistobeupdated(e.g:
pytrack_0.0.8.dfu):
dfu-util-static.exe-Dpysense_X.X.X.dfu
Iftheupdatewassuccessful,amessage,"Done!"shouldappearinthebottomofthe
commandprompt.
Double-checkSerialUSB(CDC)driverisinstalledinApplicationmode:if,bymistake,
the libusbkdriverwasinstalledwhiletheUSBIDistheApplicationmode( 0xF013for
Pytrackor 0xF012forPysense),thenthe SerialUSB(CDC)driverhastobeinstalledfor
applicationmode.ThiswillallowWindowstoallocateaCOMport,whichisrequiredfor
REPLconsole.
3.2.1UpdatingFirmware
127
UsingDFU-utilwithPytrack,PysenseandExpansionBoard
v3
Toenterupdatemodefollowthesesteps:
1. Unplugthedevice
2. Pressthebuttonandkeepitheld(ontheExpansionBoardthe S1button)
3. PlugintheUSBcabletothehostcomputerandwait1secondbeforereleasingthe
button
4. Afterthisyouwillhaveapproximately7secondstoruntheDFU-utiltool
MacOSandLinux:
$dfu-util-Dpytrack_0.0.8.dfu
Anoutput,similartotheonebelow,willappearuponsuccessfulinstallation:
3.2.1UpdatingFirmware
128
dfu-util0.9
Copyright2005-2009WestonSchmidt,HaraldWelteandOpenMokoInc.
Copyright2010-2016TormodVoldenandStefanSchmidt
ThisprogramisFreeSoftwareandhasABSOLUTELYNOWARRANTY
Pleasereportbugstohttp://sourceforge.net/p/dfu-util/tickets/
MatchvendorIDfromfile:04d8
MatchproductIDfromfile:f014
OpeningDFUcapableUSBdevice...
ID04d8:f014
Run-timedeviceDFUversion0100
ClaimingUSBDFURuntimeInterface...
Determiningdevicestatus:state=dfuIDLE,status=0
dfu-util:WARNING:RuntimedevicealreadyinDFUstate?!?
ClaimingUSBDFUInterface...
SettingAlternateSetting#0...
Determiningdevicestatus:state=dfuIDLE,status=0
dfuIDLE,continuing
DFUmodedeviceDFUversion0100
Devicereturnedtransfersize64
CopyingdatafromPCtoDFUdevice
Download[=========================]100%16384bytes
Downloaddone.
state(2)=dfuIDLE,status(0)=Noerrorconditionispresent
Done!
Debugging
Using lsusbcommand,thePytrack/Pysensedeviceshouldbevisibleinbothnormaland
bootloadermodes.
Forexemple,aPytrackboardisvisibleaseither:
Bus020Device004:ID04d8:f014MicrochipTechnologyInc.ApplicationSpecific
Device
thisisbootloadermode( f014isUSBPID),activejustfor7-8seconds,ifthereset
buttonwasjustpressedbeforepluggingUSBconnector.
Bus020Device005:ID04d8:f013MicrochipTechnologyInc.PytrackSerial:Pyabcde0
thisisnormal,applicationmode( f013isUSBPID),thismeansthebootloader
verifiedapplicationpartitionanditboot-upcorrectly.
3.2.1UpdatingFirmware
129
Windows7Drivers
PytrackandPysensewillworkoutoftheboxforWindows8/10/+,macOSaswellasLinux.
IfusingWindows7,driverstosupporttheboardswillneedtobeinstalled.
Pleasefollowtheinstructionsbelowtoinstalltherequireddrivers.
Download
Pleasedownloadthedriversoftwarefromthelinkbelow.
Pytrack/Pysense/Pyscan/Expansionboard3Driver
Installation
FirstnavigateopentheWindowsstartmenuandsearch/navigateto DeviceManager.You
shouldseeyourPytrack/Pysenseinthedropdownunderotherdevices.
Rightclickthedeviceandselect UpdateDriverSoftware.
3.2.2InstallingDrivers-Windows7
130
SelecttheoptiontoBrowsemycomputerfordriversoftware.
Nextyouwillneedtonavigatetowhereyoudownloadedthedriverto(e.g.Downloads
Folder).
3.2.2InstallingDrivers-Windows7
131
Specifythefolderinwhichthedriversarecontained.Ifyouhaven'textractedthe .zipfile,
pleasedothisbeforeselectingthefolder.
Youmayreceiveawarning,suggestingthatwindowscan'tverifythepublisherofthisdriver.
Click Installthisdriversoftwareanywayasthislinkpointstoourofficialdriver.
3.2.2InstallingDrivers-Windows7
132
Iftheinstallationwassuccessful,youshouldnowseeawindowspecifyingthatthedriver
wascorrectlyinstalled.
Toconfirmthattheinstallationwascorrect,navigatebacktothe DeviceManagerandclick
thedropdownforotherdevices.Thewarninglabelshouldnowbegoneand
Pytrack/Pysenseshouldbeinstalled.
3.2.2InstallingDrivers-Windows7
133
3.2.2InstallingDrivers-Windows7
134
InstallingLibraries
ToutilisethesensorsonthePytrackandPysense,Pycomhaswrittenlibrariestomake
readingto/fromthevarioussensorsaccessibleviaanAPI.Theselibrariesresideatthe
PycomGitHubrepositoryandthelatestversionscanbefoundunderthereleasespage.
GitHubRepository
Downloadtherepositoryasa .zipfile,navigatetothecorrectdevice(Pysense/Pytrack),
extractthefilesandthenuploadthedesiredfilestothedeviceintheinstructionsbelow.
UploadingtheLibrariestoaDevice
Theselibrariesshouldbeuploadedtoadevice(LoPy,SiPy,WiPy2.0,etc.)inthesame
processasastandardMicroPythonlibrary.Thevarious .pyfilesshouldbeplacedintothe
/libfolderonthedevice.Forexample,ifusingthePysenseandtheuserwishestoenable
theonlyAccelerometerandtheLightSensor,theyshouldplacethefollowing .pyfilesinto
thedevice's /libfolder:
-pysense.py
-LIS2HH12.py
-LTR329ALS01.py
Addasmanyorasfewofthelibrariesthatarerequired.
InadditiontothePysenseorPytrackspecificlibraries,youalsoneedtouploadthe
pycoproc.pyfilefromthe _lib/pycoproc_folderinsidethelibrariesarchive.
ThePytrackandPysenseboardsbehavethesameastheExpansionBoard.Upload,
RunanduploadcodetoPycommodulesviathePymakrPlugin,inexactlythesame
process.
Importing/UsingtheLibraries
Oncethelibrariesareuploadedtothedevice,theycanbeused/importedasatypical
MicroPythonlibrarywouldbe.Forexample,importingandusingthelightsensoronthe
Pysense:
3.2.3InstallingLibraries
135
frompysenseimportPysense
fromLTR329ALS01importLTR329ALS01
py=Pysense()
lt=LTR329ALS01(py)
print(lt.light())
3.2.3InstallingLibraries
136
APIReference
Tosimplifyusability,APIsforthelibrarieshavebeencreated,abstractingawaythelowlevel
interactionswiththesensors.Thenextfollowingpagesrefertotherespectivelibrariesfor
thePytrackandPysense.
3.3APIReference
137
PytrackAPI
ThischapterdescribesthevariouslibrarieswhicharedesignedforthePytrackboard.This
includesdetailsaboutthevariousmethodsandclassesavailableforeachofthePytrack’s
sensors.
3-AxisAccelerometer(LIS2HH12)
Pytrackhasa3-AxisAccelerometerthatprovidesoutputsforaccelerationaswellasroll,
pitchandyaw.
Constructors
classLIS2HH12(pytrack=None,sda='P22',scl='P21')
Createsa LIS2HH12object,thatwillreturnvaluesforacceleration,roll,pitchandyaw.
ConstructormustbepassedaPytrackorI2Cobjecttosuccessfullyconstruct.
Methods
LIS2HH12.acceleration()
Readtheaccelerationfromthe LIS2HH12.Returnsatuplewiththe3valuesofacceleration
(G).
LIS2HH12.roll()
Readthecurrentrollfromthe LIS2HH12.Returnsafloatindegreesintherange-180to
180.
LIS2HH12.pitch()
Readthecurrentpitchfromthe LIS2HH12.Returnsafloatindegreesintherange-90to90.
Oncetheboardtiltsbeyondthisrangethevalueswillrepeat.Thisisduetoalackofyaw
measurement,makingitnotpossibletoknowtheexactorientationoftheboard.
GPSwithGLONASS(QuectelL76-LGNSS)
PytrackhasaGPS(withGLONASS)thatprovidesoutputslongitude/latitude,speedand
otherinformationaboutthePytrack'slocation.
3.3.1Pytrack
138
Constructors
classL76GNSS(pytrack=None,sda='P22',scl='P21',timeout=None)
Createsa L76GNSSobject,thatwillreturnvaluesforlongitudeandlatitude.Constructormust
bepassedaPytrackorI2Cobjecttosuccessfullyconstruct.Setthe timeouttoatime
period(inseconds)fortheGPStosearchforalock.Ifalockisnotfoundbythetimethe
timeouthasexpired,the coordinatesmethodwillreturn (None,None).
Methods
L76GNSS.coordinates(debug=False)
Readthelongitudeandlatitudefromthe L76GNSS.Returnsatuplewiththelongitudeand
latitude.With debugsetto TruetheoutputfromtheGPSisverbose.
Pleasenotethatmorefunctionalityisbeingaddedweeklytotheselibraries.Ifarequired
featureisnotavailable,feelfreetocontributewithapullrequestattheLibrariesGitHub
repository
3.3.1Pytrack
139
PysenseAPI
ThischapterdescribesthevariouslibrarieswhicharedesignedforthePysenseBoard.This
includesdetailsaboutthevariousmethodsandclassesavailableforeachofthePysense’s
sensors.
3-AxisAccelerometer(LIS2HH12)
Pysensehasa3-AxisAccelerometerthatprovidesoutputsforaccelerationaswellasroll,
pitchandyaw.
Constructors
classLIS2HH12(pysense=None,sda='P22',scl='P21')
Createsa LIS2HH12object,thatwillreturnvaluesforacceleration,roll,pitchandyaw.
ConstructormustbepassedaPysenseorI2Cobjecttosuccessfullyconstruct.
Methods
LIS2HH12.acceleration()
Readtheaccelerationfromthe LIS2HH12.Returnsatuplewiththe3valuesofacceleration
(G).
LIS2HH12.roll()
Readthecurrentrollfromthe LIS2HH12.Returnsafloatindegreesintherange-180to
180.
LIS2HH12.pitch()
Readthecurrentpitchfromthe LIS2HH12.Returnsafloatindegreesintherange-90to90.
Oncetheboardtiltsbeyondthisrangethevalueswillrepeat.Thisisduetoalackofyaw
measurement,makingitnotpossibletoknowtheexactorientationoftheboard.
DigitalAmbientLightSensor(LTR-329ALS-01)
Pysensehasaduallightsensorthatprovidesoutputsforexternallightlevelsinlux.Seethe
datasheetformoreinformationaboutthewavelengthsofthetwosensors.
3.3.2Pysense
140
Constructors
classLTR329ALS01(pysense=None,sda='P22',scl='P21',gain=ALS_GAIN_1X,
integration=ALS_INT_100,rate=ALS_RATE_500)
Createsa LTR329ALS01object,thatwillreturnvaluesforlightinlux.Constructormustbe
passedaPysenseorI2Cobjecttosuccessfullyconstruct.
Methods
LTR329ALS01.light()
Readthelightlevelsofboth LTR329ALS01sensors.Returnsatuplewithtwovaluesforlight
levelsinlux.
Arguments
Thefollowingargumentsmaybepassedintotheconstructor.
gain
ALS_GAIN_1X,ALS_GAIN_2X,ALS_GAIN_4X,ALS_GAIN_8X,ALS_GAIN_48X,
ALS_GAIN_96X
integration
ALS_INT_50,ALS_INT_100,ALS_INT_150,ALS_INT_200,ALS_INT_250,ALS_INT_300,
ALS_INT_350,ALS_INT_400
rate
ALS_RATE_50,ALS_RATE_100,ALS_RATE_200,ALS_RATE_500,ALS_RATE_1000,
ALS_RATE_2000
HumidityandTemperatureSensor(SI7006A20)
PysensehasaHumidityandTemperaturesensorthatprovidesvaluesofrelativehumidity
andexternaltemperature.
Constructors
classSI7006A20(pysense=None,sda='P22',scl='P21')
Createsa SI7006A20object,thatwillreturnvaluesforhumidity(%)andtemperature('C).
ConstructormustbepassedaPysenseorI2Cobjecttosuccessfullyconstruct.
3.3.2Pysense
141
Methods
SI7006A20.humidity()
Readtherelativehumidityofthe SI7006A20.Returnsafloatwiththepercentagerelative
humidity.
SI7006A20.temperature()
Readtheexternaltemperatureofthe SI7006A20.Returnsafloatwiththetemperature.
BarometricPressureSensorwithAltimeter(MPL3115A2)
PysensehasaBarometricPressuresensorthatprovidesreadingsforpressure,altitudeas
wellasanadditionaltemperaturesensor.
Constructors
classMPL3115A2(pysense=None,sda='P22',scl='P21',mode=PRESSURE)
Createsa MPL3115A2object,thatwillreturnvaluesforpressure(Pa),altitude(m)and
temperature('C).ConstructormustbepassedaPysenseorI2Cobjecttosuccessfully
construct.
Methods
MPL3115A2.pressure()
Readtheatmosphericpressureofthe MPL3115A2.Returnsafloatwiththepressurein(Pa).
MPL3115A2.altitude()
Readthealtitudeofthe MPL3115A2.Returnsafloatwiththealtitudein(m).
MPL3115A2.temperature()
Readthetemperatureofthe MPL3115A2.Returnsafloatwiththetemperaturein('C).
Arguments
Thefollowingargumentsmaybepassedintotheconstructor.
mode
3.3.2Pysense
142
PRESSURE,ALTITUDE
Pleasenotethatmorefunctionalityisbeingaddedweeklytotheselibraries.Ifarequired
featureisnotavailable,feelfreetocontributewithapullrequestattheLibrariesGitHub
repository
3.3.2Pysense
143
SleepandWakeupforPytrack/Pysense
API
Thischapterdescribesthevariousmethodsforsleepandwakeupwhichareembeddedin
PytrackandPysenselibraries.BothPytrackandPysensehavethesamemethods,although
theappropriateclass,either pytrackor pysense,hastobeinstantiated.
QuickUsageExample
ThefollowingexampleisalsoavailableatSleepWakeupExampleLibrariesGitHub
repository
3.3.3Sleep
144
#frompytrackimportPytrack
frompysenseimportPysense
fromLIS2HH12importLIS2HH12
importtime
#py=Pytrack()
py=Pysense()
#displaytheresetreasoncodeandthesleepremaininginseconds
#possiblevaluesofwakeupreasonare:
#WAKE_REASON_ACCELEROMETER=1
#WAKE_REASON_PUSH_BUTTON=2
#WAKE_REASON_TIMER=4
#WAKE_REASON_INT_PIN=8
print("Wakeupreason:"+str(py.get_wake_reason()))
print("Approximatesleepremaining:"+str(py.get_sleep_remaining())+"sec")
time.sleep(0.5)
#enablewakeupsourcefromINTpin
py.setup_int_pin_wake_up(False)
acc=LIS2HH12()
#enableactivityandalsoinactivityinterrupts,usingthedefaultcallbackhandler
py.setup_int_wake_up(True,True)
#settheaccelerationthresholdto2000mG(2G)andthemindurationto200ms
acc.enable_activity_interrupt(2000,200)
#gotosleepfor5minutesmaximumifnoaccelerometerinterrupthappens
py.setup_sleep(300)
py.go_to_sleep()
Methods
pytrack.get_sleep_remaining()
Intheeventofasleepsessionthatwasawokenbyanasynchronousevent(Accelerometer,
INTpinorResetbutton)theapproximatesleepremaininginterval(expressedinseconds)
canbefoundout.Theuserhastomanuallyuse setup_sleep()toconfigurethenextsleep
interval.
pytrack.get_wake_reason()
Returnsthelastwakeupreason.Possiblevaluesare:
3.3.3Sleep
145
#WAKE_REASON_ACCELEROMETER=1#Accelerometeractivity/inactivitydetection
#WAKE_REASON_PUSH_BUTTON=2#Pytrack/Pysenseresetbuttom
#WAKE_REASON_TIMER=4#Normaltimeoutofthesleepinterval
#WAKE_REASON_INT_PIN=8#INTpin
Note:the WAKE_REASON_INT_PINcanbeusedifthePIC_RC1pin(pin#6onExternalIO
Header)istoggled.
Asintheaboveexample,thismethodshouldbecalledatthebeginningofthescript,tofind
outthereset(wakeup)reason.
pytrack.go_to_sleep([gps=True])
Putstheboardinsleepmode,fortheduration,whichhastobesetpreviouslywith
pytrack.setup_sleep(timout_sec).TheoptionalbooleanparametersetstheGPSstate
duringsleep.
MicroPythoncode,whichisafterthisfunction,isnotexecuted,aswakeupwillrestart
MicroPython.
pytrack.setup_int_wake_up(rising,falling])
Enablesaswakeupsource,theaccelerometerINTpin(PIC-RA5).Thebooleanparameters
willindicaterisingedge(activitydetection)and/orfallingedge(inactivitydetection)is
configured.
Theaccelerometer(class LIS2HH12)hastobealsoconfiguredforacertainacceleration
thresholdandduration.Codesnippet:
frompytrackimportPytrack
fromLIS2HH12importLIS2HH12
py=Pytrack()
acc=LIS2HH12()
#enableactivityandalsoinactivityinterrupts,usingthedefaultcallbackhandler
py.setup_int_wake_up(True,True)
#settheaccelerationthresholdto2000mG(2G)andthemindurationto200ms
acc.enable_activity_interrupt(2000,200)
pytrack.setup_int_pin_wake_up([rising_edge=True])
Enablesaswakeupsource,theINTpic(PIC-RC1,pin#6onExternalIOHeader).Either
risingorfallingedgehastobeset,bydefaultit'srisingedge.
3.3.3Sleep
146
pytrack.setup_sleep(time_seconds)
Setsthesleepinterval,specifiedinseconds.Theactualsleepwillbestartedbycalling
go_to_sleep()method.
Pleasenotethatmorefunctionalityisbeingaddedweeklytotheselibraries.Ifarequired
featureisnotavailable,feelfreetocontributewithapullrequestattheLibrariesGitHub
repository
3.3.3Sleep
147
TutorialsandExamples
ThissectioncontainstutorialsandexamplesforusewithPycommodulesandExpansion
boards.
GeneralPycomtutorialscontainstutorialsthatmayberunonanyPycomdevice,suchas
connectingtoaWiFinetwork,Bluetooth,controllingI/Opinsetc.Latersectionsarespecific
totheLoPyandSiPydevicessuchassettingupaLoRanodeorconnectingtotheSigfox
network.ThefinalsectionsarerelatedtoexamplesusingthePytrackandPysense.
Beforestarting,ensurethatanyPycomdevicesarerunningthelatestfirmware;for
instructionsseeFirmwareUpdates.
Thesourcecodeforthesetutorials,alongwiththerequiredlibrariescanbefoundininthe
pycom-librariesrepository.
4.1Introduction
148
AllPycomDeviceExamples
ThissectioncontainsgenericexamplesthatwillworkacrossallPycomdevicesand
ExpansionBoards.
4.2AllPycomDeviceExamples
149
UsingtheREPLPrompt
UsingthePymakrPlugin,openandconnectadeviceoruseserialterminal(PuTTY,screen,
picocom,etc).Uponconnecting,thereshouldbeablankscreenwithaflashingcursor.Press
EnterandaMicroPythonpromptshouldappear,i.e. >>>.Let’smakesureitisworkingwith
theobligatorytest:
>>>print("HelloLoPy!")
HelloLoPy!
Intheexampleabove,the >>>charactersshouldnotbetyped.Theyaretheretoindicate
thatthetextshouldbeplacedaftertheprompt.Oncethetexthasbeenentered
print("HelloLoPy!")andpressed Enter,theoutputshouldappearonscreen,identicalto
theexampleabove.
BasicPythoncommandscanbetestedoutinasimilarfashion.
Ifthisisnotworking,tryeitherahardresetorasoftreset;seebelow.
Herearesomeotherexample,utilisingthedevice'shardwarefeatures:
>>>frommachineimportPin
>>>led=Pin('G16',mode=Pin.OUT,value=1)
>>>led(0)
>>>led(1)
>>>led.toggle()
>>>1+2
3
>>>5/2
2.5
>>>20*'py'
'pypypypypypypypypypypypypypypypypypypypy'
ResettingtheDevice
Ifsomethinggoeswrong,thedevicecanberesetwithtwomethods.Thefirstistopress
CTRL-DattheMicroPythonprompt,whichwillperformasoftreset.Amessage,asfollowing,
willappear:
4.2.1REPL
150
>>>
PYB:softreboot
MicroPythonv1.4.6-146-g1d8b5e5on2016-10-21;LoPywithESP32
Type"help()"formoreinformation.
>>>
Ifthatstillisn’tworkingahardresetcanbeperformed(power-off/on)bypressingthe RST
switch(thesmallblackbuttonnexttotheRGBLED).Usingtelnet,thiswillendthesession,
disconnectingtheprogramthatwasusedtoconnecttothePycomDevice.
4.2.1REPL
151
WLAN
TheWLANisasystemfeatureofallPycomdevices,thereforeitisenabledbydefault.
InordertoretrievethecurrentWLANinstance,run:
>>>fromnetworkimportWLAN
>>>wlan=WLAN()#wecalltheconstructorwithoutparams
Thecurrentmode( WLAN.APafterpowerup)maybecheckedbyrunning:
>>>wlan.mode()
WhenchangingtheWLANmode,iffollowingtheinstructionsbelow,theWLAN
connectiontothePycomdevicewillbebroken.Thismeanscommandswillnotrun
interactivelyoverWiFi.
Therearetwowaysaroundthis:
1. Putthissetupcodeintothe boot.pyfileofthePycomdevicesothatitgets
executedautomaticallyafterreset.
2. DuplicatetheREPLonUART.ThiswaycommandscanberunviaSerialUSB.
ConnectingtoaRouter
TheWLANnetworkclassalwaysbootsin WLAN.APmode;toconnectittoanexisting
network,theWiFiclassmustbeconfiguredasastation:
fromnetworkimportWLAN
wlan=WLAN(mode=WLAN.STA)
Nowthedevicemayproceedtoscanfornetworks:
4.2.2WLAN
152
nets=wlan.scan()
fornetinnets:
ifnet.ssid=='mywifi':
print('Networkfound!')
wlan.connect(net.ssid,auth=(net.sec,'mywifikey'),timeout=5000)
whilenotwlan.isconnected():
machine.idle()#savepowerwhilewaiting
print('WLANconnectionsucceeded!')
break
AssigningaStaticIPAddressatBootUp
Iftheuserswantstheirdevicetoconnecttoahomerouteruponbootup,usingwithafixed
IPaddress,usethefollowingscriptas /flash/boot.py:
importmachine
fromnetworkimportWLAN
wlan=WLAN()#getcurrentobject,withoutchangingthemode
ifmachine.reset_cause()!=machine.SOFT_RESET:
wlan.init(mode=WLAN.STA)
#configurationbelowMUSTmatchyourhomeroutersettings!!
wlan.ifconfig(config=('192.168.178.107','255.255.255.0','192.168.178.1','8.8.8.
8'))
ifnotwlan.isconnected():
#changethelinebelowtomatchyournetworkssid,securityandpassword
wlan.connect('mywifi',auth=(WLAN.WPA2,'mywifikey'),timeout=5000)
whilenotwlan.isconnected():
machine.idle()#savepowerwhilewaiting
Noticehowwecheckfortheresetcauseandtheconnectionstatus,thisiscrucialin
ordertobeabletosoftresettheLoPyduringatelnetsessionwithoutbreakingthe
connection.
MultipleNetworksusingaStaticIPAddress
Thefollowingscriptholdsalistwithnetsandanoptionallistof wlan_configtosetafixedIP
4.2.2WLAN
153
importos
importmachine
uart=machine.UART(0,115200)
os.dupterm(uart)
known_nets={
'<net>':{'pwd':'<password>'},
'<net>':{'pwd':'<password>','wlan_config':('10.0.0.114','255.255.0.0','10.0
.0.1','10.0.0.1')},#(ip,subnet_mask,gateway,DNS_server)
}
ifmachine.reset_cause()!=machine.SOFT_RESET:
fromnetworkimportWLAN
wl=WLAN()
wl.mode(WLAN.STA)
original_ssid=wl.ssid()
original_auth=wl.auth()
print("Scanningforknownwifinets")
available_nets=wl.scan()
nets=frozenset([e.ssidforeinavailable_nets])
known_nets_names=frozenset([keyforkeyinknown_nets])
net_to_use=list(nets&known_nets_names)
try:
net_to_use=net_to_use[0]
net_properties=known_nets[net_to_use]
pwd=net_properties['pwd']
sec=[e.secforeinavailable_netsife.ssid==net_to_use][0]
if'wlan_config'innet_properties:
wl.ifconfig(config=net_properties['wlan_config'])
wl.connect(net_to_use,(sec,pwd),timeout=10000)
whilenotwl.isconnected():
machine.idle()#savepowerwhilewaiting
print("Connectedto"+net_to_use+"withIPaddress:"+wl.ifconfig()[0])
exceptExceptionase:
print("Failedtoconnecttoanyknownnetwork,goingintoAPmode")
wl.init(mode=WLAN.AP,ssid=original_ssid,auth=original_auth,channel=6,anten
na=WLAN.INT_ANT)
ConnectingtoaWPA2-Enterprisenetwork
ConnectingwithEAP-TLS:
Beforeconnecting,obtainandcopythepublicandprivatekeystothedevice,e.g.under
location /flash/cert.Ifitisrequiredtovalidatetheserver’spublickey,anappropriateCA
certificate(chain)mustalsobeprovided.
4.2.2WLAN
154
fromnetworkimportWLAN
wlan=WLAN(mode=WLAN.STA)
wlan.connect(ssid='mywifi',auth=(WLAN.WPA2_ENT,),identity='myidentity',ca_certs='/f
lash/cert/ca.pem',keyfile='/flash/cert/client.key',certfile='/flash/cert/client.crt'
)
ConnectingwithEAP-PEAPorEAP-TTLS:
IncaseofEAP-PEAP(orEAP-TTLS),theclientkeyandcertificatearenotnecessary,onlya
usernameandpasswordpair.Ifitisrequiredtovalidatetheserver’spublickey,an
appropriateCAcertificate(chain)mustalsobeprovided.
fromnetworkimportWLAN
wlan=WLAN(mode=WLAN.STA)
wlan.connect(ssid='mywifi',auth=(WLAN.WPA2_ENT,'username','password'),identity='my
identity',ca_certs='/flash/cert/ca.pem')
4.2.2WLAN
155
Bluetooth
Atpresent,basicBLEfunctionalityisavailable.Morefeatureswillbeimplementedinthe
nearfuture,suchaspairing.Thispagewillbeupdatedinlinewiththesefeatures.
Fullinfoon bluetoothcanbefoundwithinBluetoothpageoftheFirmwareAPIReference.
ScanforBLEDevices
Scanforalloftheadvertisingdeviceswithinrangeofthescanningdevice.
bluetooth.start_scan(10)#startsscanningandstopafter10seconds
bluetooth.start_scan(-1)#startsscanningindefinitelyuntilbluetooth.stop_scan()i
scalled
RawDatafromaBLEDevice
Aquickusageexamplethatscansandprintstherawdatafromadvertisements.
fromnetworkimportBluetooth
bluetooth=Bluetooth()
bluetooth.start_scan(-1)#startscanningwithnotimeout
whileTrue:
print(bluetooth.get_adv())
ConnecttoaBLEDevice
Connectingtoadevicethatissendingadvertisements.
4.2.3Bluetooth
156
fromnetworkimportBluetooth
importubinascii
bluetooth=Bluetooth()
#scanuntilwecanconnecttoanyBLEdevicearound
bluetooth.start_scan(-1)
adv=None
whileTrue:
adv=bluetooth.get_adv()
ifadv:
try:
bluetooth.connect(adv.mac)
except:
#startscanningagain
bluetooth.start_scan(-1)
continue
break
print("Connectedtodevicewithaddr={}".format(ubinascii.hexlify(adv.mac)))
ConnecttoaBLEDeviceandRetrieveData
Connectingtoadevicenamed'HeartRate'andreceivingdatafromit’sservices.
4.2.3Bluetooth
157
fromnetworkimportBluetooth
importtime
bt=Bluetooth()
bt.start_scan(-1)
whileTrue:
adv=bt.get_adv()
ifadvandbt.resolve_adv_data(adv.data,Bluetooth.ADV_NAME_CMPL)=='HeartRate':
try:
conn=bt.connect(adv.mac)
services=conn.services()
forserviceinservices:
time.sleep(0.050)
iftype(service.uuid())==bytes:
print('Readingcharsfromservice={}'.format(service.uuid()))
else:
print('Readingcharsfromservice=%x'%service.uuid())
chars=service.characteristics()
forcharinchars:
if(char.properties()&Bluetooth.PROP_READ):
print('char{}value={}'.format(char.uuid(),char.read()))
conn.disconnect()
break
except:
pass
else:
time.sleep(0.050)
RetrievetheName&ManufacturerfromaBLEDevice
Using resolve_adv_data()toattempttoretrievethenameandmanufacturerdatafromthe
advertiser.
4.2.3Bluetooth
158
importubinascii
fromnetworkimportBluetooth
bluetooth=Bluetooth()
bluetooth.start_scan(20)
whilebluetooth.isscanning():
adv=bluetooth.get_adv()
ifadv:
#trytogetthecompletename
print(bluetooth.resolve_adv_data(adv.data,Bluetooth.ADV_NAME_CMPL))
mfg_data=bluetooth.resolve_adv_data(adv.data,Bluetooth.ADV_MANUFACTURER_DAT
A)
ifmfg_data:
#trytogetthemanufacturerdata(Apple'siBeacondataissenthere)
print(ubinascii.hexlify(mfg_data))
4.2.3Bluetooth
159
HTTPS
Basicconnectionusing ssl.wrap_socket().
importsocket
importssl
s=socket.socket()
ss=ssl.wrap_socket(s)
ss.connect(socket.getaddrinfo('www.google.com',443)[0][-1])
Belowisanexampleusingcertificateswiththeblynkcloud.
Certificatewasdownloadedfromtheblynkexamplesfolderandplacedin /flash/cert/on
thedevice.
importsocket
importssl
s=socket.socket()
ss=ssl.wrap_socket(s,cert_reqs=ssl.CERT_REQUIRED,ca_certs='/flash/cert/ca.pem')
ss.connect(socket.getaddrinfo('cloud.blynk.cc',8441)[0][-1])
Formoreinfo,checkthe sslmoduleintheAPIreference.
4.2.4HTTPS
160
MQTT
MQTTisalightweightmessagingprotocolthatisidealforsendingsmallpacketsofdatato
andfromIoTdevicesviaWiFi.
ThebrokerusedinthisexampleistheIOAdafruit)platform,whichisfreeandallowsfor
tinkeringwithMQTT.
VisitIOAdafruitandcreateanaccount.You'llneedtogetholdofanAPIKeyaswellasyour
credentials.VisitthisguideformoreinformationaboutMQTTandhowtouseitwith
Adafruit'sBroker.
ThisexamplewillsendamessagetoatopicontheAdafruitMQTTbrokerandthenalso
subscribetothesametopic,inordertoshowhowtousethesubscribefunctionality.
frommqttimportMQTTClient
fromnetworkimportWLAN
importmachine
importtime
defsub_cb(topic,msg):
print(msg)
wlan=WLAN(mode=WLAN.STA)
wlan.connect("yourwifinetwork",auth=(WLAN.WPA2,"wifipassword"),timeout=5000)
whilenotwlan.isconnected():
machine.idle()
print("ConnectedtoWiFi\n")
client=MQTTClient("device_id","io.adafruit.com",user="your_username",password="you
r_api_key",port=1883)
client.set_callback(sub_cb)
client.connect()
client.subscribe(topic="youraccount/feeds/lights")
whileTrue:
print("SendingON")
client.publish(topic="youraccount/feeds/lights",msg="ON")
time.sleep(1)
print("SendingOFF")
client.publish(topic="youraccount/feeds/lights",msg="OFF")
client.check_msg()
time.sleep(1)
4.2.5MQTT
161
4.2.5MQTT
162
AmazonWebServices
TheAWSIoTplatformenablesdevicestoconnecttotheAmazoncloudandletsapplications
inthecloudinteractwithInternet-connectedthings.CommonIoTapplicationseithercollect
andprocesstelemetryfromdevicesorenableuserstocontroladeviceremotely.Things
reporttheirstatebypublishingmessages,inJSONformat,onMQTTtopics.
FormoreinformationseethisPDFFile.
GettingStartedwithAWSIoT
Creatingthemessagebroker(Amazonwebsite):
SignintotheAWSManagementConsole
NavigatetotheIoTConsolebyclickingontheAWSIoTlink
Intheleftnavigationpane,chooseRegister/Manage
Clickonthecreatebutton,giveyourdeviceanameandpresscreate
Clickonthedevicethathasbeencreated
OntheDetailspage,intheleftnavigationpane,chooseSecurity
OntheCertificatespage,chooseCreatecertificate
Downloadallthecertificates,thenpresstheActivateandtheAttachaPolicybuttons.
Seeimage
ClickontheCreateNewPolicybutton
OntheCreatePolicypage,chooseapolicynameandtheactionstoauthorise.
Gotothecertificatespage,clickonthethreedotsofyourcertificateandattachthe
policytothecertificateasshowninthediagram
Settingupthedevice(Pycomdevice):
DownloadthelatestsamplecodefromthePycomGitHubRepository.
ConnecttothedeviceviaFTPandputtherootCAcertificate,theclientcertificate
(*.pem.crt)andtheprivatekey( *.private.pem.key)inthe /flash/certfolder.
UpdatetheconfigfilewithyourWiFisettings,theAWSHostandthecertificatepaths.
Putthe config.pyandthe main.pyinthedeviceflash
Configuration( config.py):
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ThisfilecontainstheWiFi,certificatepathsandapplicationspecificsettingsthatneedtobe
updatedbytheuser.
#WiFiconfiguration
WIFI_SSID='my_wifi_ssid'
WIFI_PASS='my_wifi_password'
#AWSgeneralconfiguration
AWS_PORT=8883
AWS_HOST='aws_host_url'
AWS_ROOT_CA='/flash/cert/aws_root.ca'
AWS_CLIENT_CERT='/flash/cert/aws_client.cert'
AWS_PRIVATE_KEY='/flash/cert/aws_private.key'
##################Subscribe/Publishclient#################
CLIENT_ID='PycomPublishClient'
TOPIC='PublishTopic'
OFFLINE_QUEUE_SIZE=-1
DRAINING_FREQ=2
CONN_DISCONN_TIMEOUT=10
MQTT_OPER_TIMEOUT=5
LAST_WILL_TOPIC='PublishTopic'
LAST_WILL_MSG='ToAll:Lastwillmessage'
#######################Shadowupdater########################
#THING_NAME="mythingname"
#CLIENT_ID="ShadowUpdater"
#CONN_DISCONN_TIMEOUT=10
#MQTT_OPER_TIMEOUT=5
#######################DeltaListener########################
#THING_NAME="mythingname"
#CLIENT_ID="DeltaListener"
#CONN_DISCONN_TIMEOUT=10
#MQTT_OPER_TIMEOUT=5
#######################ShadowEcho########################
#THING_NAME="mythingname"
#CLIENT_ID="ShadowEcho"
#CONN_DISCONN_TIMEOUT=10
#MQTT_OPER_TIMEOUT=5
Subscibe/Publish( main.py)
Tosubscribetoatopic:
GototheAWSIotpage,clickonmanageandchooseyourdevice
Fromthelefthandside,chooseActivityandthenclickMQTTclient.
Choosethetopicnameyouenteredintheconfigurationfile.
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Messagesshouldbepublishedasshowninthediagram
#userspecifiedcallbackfunction
defcustomCallback(client,userdata,message):
print("Receivedanewmessage:")
print(message.payload)
print("fromtopic:")
print(message.topic)
print("--------------\n\n")
#configuretheMQTTclient
pycomAwsMQTTClient=AWSIoTMQTTClient(config.CLIENT_ID)
pycomAwsMQTTClient.configureEndpoint(config.AWS_HOST,config.AWS_PORT)
pycomAwsMQTTClient.configureCredentials(config.AWS_ROOT_CA,config.AWS_PRIVATE_KEY,co
nfig.AWS_CLIENT_CERT)
pycomAwsMQTTClient.configureOfflinePublishQueueing(config.OFFLINE_QUEUE_SIZE)
pycomAwsMQTTClient.configureDrainingFrequency(config.DRAINING_FREQ)
pycomAwsMQTTClient.configureConnectDisconnectTimeout(config.CONN_DISCONN_TIMEOUT)
pycomAwsMQTTClient.configureMQTTOperationTimeout(config.MQTT_OPER_TIMEOUT)
pycomAwsMQTTClient.configureLastWill(config.LAST_WILL_TOPIC,config.LAST_WILL_MSG,1)
#ConnecttoMQTTHost
ifpycomAwsMQTTClient.connect():
print('AWSconnectionsucceeded')
#Subscribetotopic
pycomAwsMQTTClient.subscribe(config.TOPIC,1,customCallback)
time.sleep(2)
#Sendmessagetohost
loopCount=0
whileloopCount<8:
pycomAwsMQTTClient.publish(config.TOPIC,"NewMessage"+str(loopCount),1)
loopCount+=1
time.sleep(5.0)
Shadowupdater( main.py)
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#userspecifiedcallbackfunctions
defcustomShadowCallback_Update(payload,responseStatus,token):
ifresponseStatus=="timeout":
print("Updaterequest"+token+"timeout!")
ifresponseStatus=="accepted":
payloadDict=json.loads(payload)
print("Updaterequestwithtoken:"+token+"accepted!")
print("property:"+str(payloadDict["state"]["desired"]["property"]))
ifresponseStatus=="rejected":
print("Updaterequest"+token+"rejected!")
defcustomShadowCallback_Delete(payload,responseStatus,token):
ifresponseStatus=="timeout":
print("Deleterequest"+token+"timeout!")
ifresponseStatus=="accepted":
print("Deleterequestwithtoken:"+token+"accepted!")
ifresponseStatus=="rejected":
print("Deleterequest"+token+"rejected!")
#configuretheMQTTclient
pycomAwsMQTTShadowClient=AWSIoTMQTTShadowClient(config.CLIENT_ID)
pycomAwsMQTTShadowClient.configureEndpoint(config.AWS_HOST,config.AWS_PORT)
pycomAwsMQTTShadowClient.configureCredentials(config.AWS_ROOT_CA,config.AWS_PRIVATE_K
EY,config.AWS_CLIENT_CERT)
pycomAwsMQTTShadowClient.configureConnectDisconnectTimeout(config.CONN_DISCONN_TIMEOUT
)
pycomAwsMQTTShadowClient.configureMQTTOperationTimeout(config.MQTT_OPER_TIMEOUT)
#ConnecttoMQTTHost
ifpycomAwsMQTTShadowClient.connect():
print('AWSconnectionsucceeded')
deviceShadowHandler=pycomAwsMQTTShadowClient.createShadowHandlerWithName(config.THIN
G_NAME,True)
#DeleteshadowJSONdoc
deviceShadowHandler.shadowDelete(customShadowCallback_Delete,5)
#Updateshadowinaloop
loopCount=0
whileTrue:
JSONPayload='{"state":{"desired":{"property":'+str(loopCount)+'}}}'
deviceShadowHandler.shadowUpdate(JSONPayload,customShadowCallback_Update,5)
loopCount+=1
time.sleep(5)
DeltaListener( main.py)
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#CustomShadowcallback
defcustomShadowCallback_Delta(payload,responseStatus,token):
payloadDict=json.loads(payload)
print("property:"+str(payloadDict["state"]["property"]))
print("version:"+str(payloadDict["version"]))
#configuretheMQTTclient
pycomAwsMQTTShadowClient=AWSIoTMQTTShadowClient(config.CLIENT_ID)
pycomAwsMQTTShadowClient.configureEndpoint(config.AWS_HOST,config.AWS_PORT)
pycomAwsMQTTShadowClient.configureCredentials(config.AWS_ROOT_CA,config.AWS_PRIVATE_K
EY,config.AWS_CLIENT_CERT)
pycomAwsMQTTShadowClient.configureConnectDisconnectTimeout(config.CONN_DISCONN_TIMEOUT
)
pycomAwsMQTTShadowClient.configureMQTTOperationTimeout(config.MQTT_OPER_TIMEOUT)
#ConnecttoMQTTHost
ifpycomAwsMQTTShadowClient.connect():
print('AWSconnectionsucceeded')
deviceShadowHandler=pycomAwsMQTTShadowClient.createShadowHandlerWithName(config.THIN
G_NAME,True)
#Listenondeltas
deviceShadowHandler.shadowRegisterDeltaCallback(customShadowCallback_Delta)
#Loopforever
whileTrue:
time.sleep(1)
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ADC
ThisexampleisasimpleADCsample.Formoreinformationpleasesee ADC.
frommachineimportADC
adc=ADC(0)
adc_c=adc.channel(pin='P13')
adc_c()
adc_c.value()
Calibration
CurrentlytheESP32'sADCisnotcalibratedfromthefactory.Thismeansitmustbe
calibratedeachtimeyouwishtouseit.Todothisyoumustfirstlymeasuretheinternal
voltagereference.Thefollowingcodewillconnectthe1.1vreferenceto P22
frommachineimportADC
adc=ADC()
#OutputVrefofP22
adc.vref_to_pin('P22')
Nowthatthevoltagereferenceisexternallyaccessibleyoushouldmeasureitwiththemost
accuratevoltmeteryouhaveaccessto.Notedownthereadinginmillivolts,e.g. 1120.To
disconnectthe1.1vreferencefrom P22pleaseresetyourmodule.Youcannowcalibrate
theADCbytellingitthetruevalueoftheinternalreference.Youshouldthencheckyour
calibrationbyconnectingtheADCtoaknownvoltagesource.
#Setcalibration-seenoteabove
adc.vref(1100)
#Checkcalibrationbyreadingaknownvoltage
adc_c=adc.channel(pin='P16',attn=ADC.ATTN_11DB)
print(adc_c.voltage())
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I2C
ThefollowingexamplereceivesdatafromalightsensorusingI2C.Sensorusedisthe
BH1750FVIDigitalLightSensor.
importtime
frommachineimportI2C
importbh1750fvi
i2c=I2C(0,I2C.MASTER,baudrate=100000)
light_sensor=bh1750fvi.BH1750FVI(i2c,addr=i2c.scan()[0])
while(True):
data=light_sensor.read()
print(data)
time.sleep(1)
DriversfortheBH1750FVI
Placethissamplecodeintoafilenamed bh1750fvi.py.Thiscanthenbeimportedasa
library.
#SimpledriverfortheBH1750FVIdigitallightsensor
classBH1750FVI:
MEASUREMENT_TIME=const(120)
def__init__(self,i2c,addr=0x23,period=150):
self.i2c=i2c
self.period=period
self.addr=addr
self.time=0
self.value=0
self.i2c.writeto(addr,bytes([0x10]))#startcontinuos1Luxreadingsevery1
20ms
defread(self):
self.time+=self.period
ifself.time>=MEASUREMENT_TIME:
self.time=0
data=self.i2c.readfrom(self.addr,2)
self.value=(((data[0]<<8)+data[1])*1200)//1000
returnself.value
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LightsensorandLoRa
Thisisthesamecode,withaddedLoRaconnectivity,sendingtheluxvaluefromthelight
sensortoanotherLoRaenableddevice.
importsocket
importtime
importpycom
importstruct
fromnetworkimportLoRa
frommachineimportI2C
importbh1750fvi
LORA_PKG_FORMAT="!BH"
LORA_CONFIRM_FORMAT="!BB"
DEVICE_ID=1
pycom.heartbeat(False)
lora=LoRa(mode=LoRa.LORA,tx_iq=True,region=LoRa.EU868)
lora_sock=socket.socket(socket.AF_LORA,socket.SOCK_RAW)
lora_sock.setblocking(False)
i2c=I2C(0,I2C.MASTER,baudrate=100000)
light_sensor=bh1750fvi.BH1750FVI(i2c,addr=i2c.scan()[0])
while(True):
msg=struct.pack(LORA_PKG_FORMAT,DEVICE_ID,light_sensor.read())
lora_sock.send(msg)
pycom.rgbled(0x150000)
wait=5
while(wait>0):
wait=wait-0.1
time.sleep(0.1)
recv_data=lora_sock.recv(64)
if(len(recv_data)>=2):
status,device_id=struct.unpack(LORA_CONFIRM_FORMAT,recv_data)
if(device_id==DEVICE_IDandstatus==200):
pycom.rgbled(0x001500)
wait=0
time.sleep(1)
4.2.8I2C
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4.2.8I2C
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OnewireDriver
ThistutorialexplainshowtoconnectandreaddatafromaDS18x20temperaturesensor.
Theonewirelibraryisalsoavailableatthepycom-librariesGitHubRepository.
Basicusage
importtime
frommachineimportPin
fromonewireimportDS18X20
fromonewireimportOneWire
#DS18B20datalineconnectedtopinP10
ow=OneWire(Pin('P10'))
temp=DS18X20(ow)
whileTrue:
print(temp.read_temp_async())
time.sleep(1)
temp.start_conversion()
time.sleep(1)
Library
#!/usr/bin/envpython3
"""
OneWirelibraryforMicroPython
"""
importtime
importmachine
classOneWire:
CMD_SEARCHROM=const(0xf0)
CMD_READROM=const(0x33)
CMD_MATCHROM=const(0x55)
CMD_SKIPROM=const(0xcc)
def__init__(self,pin):
self.pin=pin
self.pin.init(pin.OPEN_DRAIN,pin.PULL_UP)
defreset(self):
"""
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Performtheonewireresetfunction.
ReturnsTrueifadeviceassertedapresencepulse,Falseotherwise.
"""
sleep_us=time.sleep_us
disable_irq=machine.disable_irq
enable_irq=machine.enable_irq
pin=self.pin
pin(0)
sleep_us(480)
i=disable_irq()
pin(1)
sleep_us(60)
status=notpin()
enable_irq(i)
sleep_us(420)
returnstatus
defread_bit(self):
sleep_us=time.sleep_us
enable_irq=machine.enable_irq
pin=self.pin
pin(1)#halfofthedevicesdon'tmatchCRCwithoutthisline
i=machine.disable_irq()
pin(0)
sleep_us(1)
pin(1)
sleep_us(1)
value=pin()
enable_irq(i)
sleep_us(40)
returnvalue
defread_byte(self):
value=0
foriinrange(8):
value|=self.read_bit()<<i
returnvalue
defread_bytes(self,count):
buf=bytearray(count)
foriinrange(count):
buf[i]=self.read_byte()
returnbuf
defwrite_bit(self,value):
sleep_us=time.sleep_us
pin=self.pin
i=machine.disable_irq()
pin(0)
sleep_us(1)
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pin(value)
sleep_us(60)
pin(1)
sleep_us(1)
machine.enable_irq(i)
defwrite_byte(self,value):
foriinrange(8):
self.write_bit(value&1)
value>>=1
defwrite_bytes(self,buf):
forbinbuf:
self.write_byte(b)
defselect_rom(self,rom):
"""
Selectaspecificdevicetotalkto.Passinromasabytearray(8bytes).
"""
self.reset()
self.write_byte(CMD_MATCHROM)
self.write_bytes(rom)
defcrc8(self,data):
"""
ComputeCRC
"""
crc=0
foriinrange(len(data)):
byte=data[i]
forbinrange(8):
fb_bit=(crc^byte)&0x01
iffb_bit==0x01:
crc=crc^0x18
crc=(crc>>1)&0x7f
iffb_bit==0x01:
crc=crc|0x80
byte=byte>>1
returncrc
defscan(self):
"""
ReturnalistofROMsforallattacheddevices.
EachROMisreturnedasabytesobjectof8bytes.
"""
devices=[]
diff=65
rom=False
foriinrange(0xff):
rom,diff=self._search_rom(rom,diff)
ifrom:
devices+=[rom]
ifdiff==0:
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break
returndevices
def_search_rom(self,l_rom,diff):
ifnotself.reset():
returnNone,0
self.write_byte(CMD_SEARCHROM)
ifnotl_rom:
l_rom=bytearray(8)
rom=bytearray(8)
next_diff=0
i=64
forbyteinrange(8):
r_b=0
forbitinrange(8):
b=self.read_bit()
ifself.read_bit():
ifb:#therearenodevicesorthereisanerroronthebus
returnNone,0
else:
ifnotb:#collision,twodeviceswithdifferentbitmeaning
ifdiff>ior((l_rom[byte]&(1<<bit))anddiff!=i):
b=1
next_diff=i
self.write_bit(b)
ifb:
r_b|=1<<bit
i-=1
rom[byte]=r_b
returnrom,next_diff
classDS18X20(object):
def__init__(self,onewire):
self.ow=onewire
self.roms=[romforrominself.ow.scan()ifrom[0]==0x10orrom[0]==0x28
]
defisbusy(self):
"""
CheckswetheroneoftheDS18x20devicesonthebusisbusy
performingatemperatureconversion
"""
returnnotself.ow.read_bit()
defstart_conversion(self,rom=None):
"""
StartthetempconversionononeDS18x20device.
Passthe8-bytebytesobjectwiththeROMofthespecificdeviceyouwanttor
ead.
IfonlyoneDS18x20deviceisattachedtothebusyoumayomittheromparamet
er.
"""
rom=romorself.roms[0]
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ow=self.ow
ow.reset()
ow.select_rom(rom)
ow.write_byte(0x44)#ConvertTemp
defread_temp_async(self,rom=None):
"""
ReadthetemperatureofoneDS18x20deviceiftheconversioniscomplete,
otherwisereturnNone.
"""
ifself.isbusy():
returnNone
rom=romorself.roms[0]
ow=self.ow
ow.reset()
ow.select_rom(rom)
ow.write_byte(0xbe)#Readscratch
data=ow.read_bytes(9)
returnself.convert_temp(rom[0],data)
defconvert_temp(self,rom0,data):
"""
Converttherawtemperaturedataintodegreescelsiusandreturnasafixedpo
intwith2decimalplaces.
"""
temp_lsb=data[0]
temp_msb=data[1]
ifrom0==0x10:
iftemp_msb!=0:
#convertnegativenumber
temp_read=temp_lsb>>1|0x80#truncatebit0byshifting,fillh
ighbitwith1.
temp_read=-((~temp_read+1)&0xff)#nowconvertfromtwo'scomple
ment
else:
temp_read=temp_lsb>>1#truncatebit0byshifting
count_remain=data[6]
count_per_c=data[7]
temp=100*temp_read-25+(count_per_c-count_remain)//count_per_c
returntemp
elifrom0==0x28:
return(temp_msb<<8|temp_lsb)*100//16
else:
assertFalse
4.2.9OnewireDriver
176
Threading
MicroPythonsupportsspawningthreadsbythe _threadmodule.Thefollowingexample
demonstratestheuseofthismodule.Athreadissimplydefinedasafunctionthatcan
receiveanynumberofparameters.Below3threadsarestarted,eachoneperformaprintat
adifferentinterval.
import_thread
importtime
defth_func(delay,id):
whileTrue:
time.sleep(delay)
print('Runningthread%d'%id)
foriinrange(3):
_thread.start_new_thread(th_func,(i+1,i))
UsingLocks:
import_thread
a_lock=_thread.allocate_lock()
witha_lock:
print("a_lockislockedwhilethisexecutes")
4.2.10Threading
177
RGBLED
BydefaulttheheartbeatLEDflashesinbluecolouronceevery4stosignalthatthesystem
isalive.Thiscanbeoverriddenthroughthe pycommodule.
importpycom
pycom.heartbeat(False)
pycom.rgbled(0xff00)#turnontheRGBLEDingreencolour
TheheartbeatLEDisalsousedtoindicatethatanerrorwasdetected.
ThefollowingpieceofcodeusestheRGBLEDtomakeatrafficlightthatrunsfor10cycles.
importpycom
importtime
pycom.heartbeat(False)
forcyclesinrange(10):#stopafter10cycles
pycom.rgbled(0x007f00)#green
time.sleep(5)
pycom.rgbled(0x7f7f00)#yellow
time.sleep(1.5)
pycom.rgbled(0x7f0000)#red
time.sleep(4)
Hereistheexpectedresult:
4.2.11RGBLED
178
4.2.11RGBLED
179
Timers
Detailedinformationaboutthisclasscanbefoundin Timer.
Chronometer
TheChronometercanbeusedtomeasurehowmuchtimehaselapsedinablockofcode.
Thefollowingexampleusesasimplestopwatch.
frommachineimportTimer
importtime
chrono=Timer.Chrono()
chrono.start()
time.sleep(1.25)#simulatethefirstlaptook1.25seconds
lap=chrono.read()#readelapsedtimewithoutstopping
time.sleep(1.5)
chrono.stop()
total=chrono.read()
print()
print("\ntheracertook%fsecondstofinishtherace"%total)
print("%fsecondsinthefirstlap"%lap)
print("%fsecondsinthelastlap"%(total-lap))
Alarm
TheAlarmcanbeusedtogetinterruptsataspecificinterval.Thefollowingcodeexecutesa
callbackeverysecondfor10seconds.
4.2.12Timers
180
frommachineimportTimer
classClock:
def__init__(self):
self.seconds=0
self.__alarm=Timer.Alarm(self._seconds_handler,1,periodic=True)
def_seconds_handler(self,alarm):
self.seconds+=1
print("%02dsecondshavepassed"%self.seconds)
ifself.seconds==10:
alarm.callback(None)#stopcountingafter10seconds
clock=Clock()
Therearenorestrictionstowhatcanbedoneinaninterrupt.Forexample,itispossible
toevendonetworkrequestswithaninterrupt.However,itisimportanttokeepinmind
thatinterruptsarehandledsequentially,soit’sgoodpracticetokeepthemshort.More
informationcanbefoundin InterruptHandling.
4.2.12Timers
181
PIRSensor
ThiscodereadsPIRsensortriggersfromthissimplePIRsensorandsendsanHTTP
requestforeverytrigger,inthiscasetoaDomoticzinstallation.Whenmotionisconstantly
detected,thisPIRsensorkeepsthepinhigh,inwhichcasethiscodewillkeepsending
HTTPrequestsevery10seconds(configurablewiththehold_timevariable).
Main( main.py)
importtime
fromnetworkimportWLAN
frommachineimportPin
fromdomoticzimportDomoticz
wl=WLAN(WLAN.STA)
d=Domoticz("<ip>",8080,"<hash>")
#config
hold_time_sec=10
#flags
last_trigger=-10
pir=Pin('G4',mode=Pin.IN,pull=Pin.PULL_UP)
#mainloop
print("Startingmainloop")
whileTrue:
ifpir()==1:
iftime.time()-last_trigger>hold_time_sec:
last_trigger=time.time()
print("Presencedetected,sendingHTTPrequest")
try:
return_code=d.setVariable('Presence:LivingRoom','1')
print("Requestresult:"+str(return_code))
exceptExceptionase:
print("Requestfailed")
print(e)
else:
last_trigger=0
print("Nopresence")
time.sleep_ms(500)
print("Exitedmainloop")
4.2.13PIRSensor
182
Boot( boot.py)
FormoreWiFiscripts,seethewlanstepbysteptutorial.
importos
importmachine
uart=machine.UART(0,115200)
os.dupterm(uart)
known_nets={
'NetworkID':{'pwd':'<password>','wlan_config':('10.0.0.8','255.255.0.
0','10.0.0.1','10.0.0.1')},
}
fromnetworkimportWLAN
wl=WLAN()
ifmachine.reset_cause()!=machine.SOFT_RESET:
wl.mode(WLAN.STA)
original_ssid=wl.ssid()
original_auth=wl.auth()
print("Scanningforknownwifinets")
available_nets=wl.scan()
nets=frozenset([e.ssidforeinavailable_nets])
known_nets_names=frozenset([keyforkeyinknown_nets])
net_to_use=list(nets&known_nets_names)
try:
net_to_use=net_to_use[0]
net_properties=known_nets[net_to_use]
pwd=net_properties['pwd']
sec=[e.secforeinavailable_netsife.ssid==net_to_use][0]
if'wlan_config'innet_properties:
wl.ifconfig(config=net_properties['wlan_config'])
wl.connect(net_to_use,(sec,pwd),timeout=10000)
whilenotwl.isconnected():
machine.idle()#savepowerwhilewaiting
print("Connectedto"+net_to_use+"withIPaddress:"+wl.ifconfig()[0])
exceptExceptionase:
print("Failedtoconnecttoanyknownnetwork,goingintoAPmode")
wl.init(mode=WLAN.AP,ssid=original_ssid,auth=original_auth,channel=6,anten
na=WLAN.INT_ANT)
DomoticzWrapper( domoticz.py)
4.2.13PIRSensor
183
importsocket
classDomoticz:
def__init__(self,ip,port,basic):
self.basic=basic
self.ip=ip
self.port=port
defsetLight(self,idx,command):
returnself.sendRequest("type=command&param=switchlight&idx="+idx+"&switchcmd="
+command)
defsetVariable(self,name,value):
returnself.sendRequest("type=command&param=updateuservariable&vtype=0&vname="
+name+"&vvalue="+value)
defsendRequest(self,path):
try:
s=socket.socket()
s.connect((self.ip,self.port))
s.send(b"GET/json.htm?"+path+"HTTP/1.1\r\nHost:pycom.io\r\nAuthorizatio
n:Basic"+self.basic+"\r\n\r\n")
status=str(s.readline(),'utf8')
code=status.split("")[1]
s.close()
returncode
exceptException:
print("HTTPrequestfailed")
return0
4.2.13PIRSensor
184
ModbusProtocol
Modbusisamessagingprotocolthatdefinesthepacketstructurefortransferringdata
betweendevicesinamaster/slavearchitecture.Theprotocolisindependentofthe
transmissionmediumandisusuallytransmittedoverTCP(MODBUSTCP)orserial
communication(MODBUSRTU).Modbusisintendedasarequest/replyprotocoland
deliversservicesspecifiedbyfunctioncodes.Thefunctioncodeintherequesttellsthe
addressedslavewhatkindofactiontoperform.Thefunctioncodesmostcommonly
supportedbydevicesarelistedbelow.
FunctionName FunctionCode
ReadCoils 0x01
ReadDiscreteInputs 0x02
ReadHoldingRegisters 0x03
ReadInputRegisters 0x04
WriteSingleCoil 0x05
WriteSingleRegister 0x06
WriteMultipleCoils 0x0F
WriteMultipleRegisters 0x10
FormoreinformationontheMODBUSRTUseethefollowingPDFFile.Informationonthe
MODBUSTCPcanbefoundhere.
PycomModbusLibrary
PythonlibrariesandsamplecodethatsupportModbusTCPandModbusRTUareavailable
atthefollowingGitHubRepository.Tousethislibrary,connecttothetargetPycomdevice
viaftpanduploadtheuModbusfolderto /flash.Adescriptionofthesupportedfunction
codesisfoundbelow.
ReadCoils
Thisfunctioncoderequeststhestatus(ON/OFF)ofdiscretecoilsonaremotedevice.The
slavedeviceaddress,theaddressofthefirstcoilandthenumberofcoilsmustbespecified
intherequest.Theaddressofthefirstcoilis0andamaximumof2000contiguouscoilscan
beread.Pythonsamplecodeisshownbelow.
4.2.14Modbus
185
slave_addr=0x0A
starting_address=0x00
coil_quantity=100
coil_status=modbus_obj.read_coils(slave_addr,starting_address,coil_quantity)
print('Coilstatus:'+''.join('{:d}'.format(x)forxincoil_status))
ReadDiscreteInputs
Thiscommandisusedtoreadthestatus(ON/OFF)ofdiscreteinputsonaremotedevice.
Theslaveaddress,theaddressofthefirstinput,andthequantityofinputstobereadmust
bespecified.Theaddressofthefirstinputis0andamaximumof2000continuousinputs
canberead.ThePythonsamplecodeisshownbelow.
slave_addr=0x0A
starting_address=0x0
input_quantity=100
input_status=modbus_obj.read_discrete_inputs(slave_addr,starting_address,input_qua
ntity)
print('Inputstatus:'+''.join('{:d}'.format(x)forxininput_status))
ReadHoldingRegisters
Thisfunctioncodeisusedtoreadthecontentsofanalogueoutputholdingregisters.The
slaveaddress,thestartingregisteraddress,thenumberofregisterstoreadandthesignof
thedatamustbespecified.Registeraddressesstartat0andamaximumof125continuous
registerscanberead.
slave_addr=0x0A
starting_address=0x00
register_quantity=100
signed=True
register_value=modbus_obj.read_holding_registers(slave_addr,starting_address,regis
ter_quantity,signed)
print('Holdingregistervalue:'+''.join('{:d}'.format(x)forxinregister_value))
ReadInputRegisters
Thiscommandisusedtoreadupto125continuousinputregistersonaremotedevice.The
slaveaddress,thestartingregisteraddress,thenumberofinputregistersandthesignofthe
datamustbespecified.Theaddressofthefirstinputregistersis0.
4.2.14Modbus
186
slave_addr=0x0A
starting_address=0x00
register_quantity=100
signed=True
register_value=modbus_obj.read_input_registers(slave_addr,starting_address,registe
r_quantity,signed)
print('Inputregistervalue:'+''.join('{:d}'.format(x)forxinregister_value))
WriteSingleCoil
Thisfunctioncodeisusedtowritethestateofadiscretecoilonaremotedevice.Avalueof
0xFF00meansthecoilshouldbesettoON,whileavalueof 0x0000meansthecoilshould
besettoOFF.ThePythonsamplecodetosetthecoilataddress 0x00,toanONstateis
shownbelow.
slave_addr=0x0A
output_address=0x00
output_value=0xFF00
return_flag=modbus_obj.write_single_coil(slave_addr,output_address,output_value)
output_flag='Success'ifreturn_flagelse'Failure'
print('Writingsinglecoilstatus:'+output_flag)
WriteSingleRegister
Thiscommandisusedtowritethecontentsofananalogoutputholdingregisteronaremote
device.Theslaveaddress,theregisteraddress,theregistervalue,andthesignatureofthe
datamustbespecified.Asforalltheothercommands,theregisteraddressesstartfrom0.
slave_addr=0x0A
register_address=0x01
register_value=-32768
signed=True
return_flag=modbus_obj.write_single_register(slave_addr,register_address,register_
value,signed)
output_flag='Success'ifreturn_flagelse'Failure'
print('Writingsinglecoilstatus:'+output_flag)
WriteMultipleCoils
4.2.14Modbus
187
Thisfunctioncodeisusedtosetacontinuoussequenceofcoils,inaremotedevice,to
eitherONorOFF.Theslaveaddress,thestartingaddressofthecoilsandanarraywiththe
coilstatesmustbespecified.
slave_addr=0x0A
starting_address=0x00
output_values=[1,1,1,0,0,1,1,1,0,0,1,1,1]
return_flag=modbus_obj.write_multiple_coils(slave_addr,starting_address,output_val
ues)
output_flag='Success'ifreturn_flagelse'Failure'
print('Writingmultiplecoilstatus:'+output_flag)
WriteMultipleRegisters
Thiscommandisusedtowritethecontentsofacontinuoussequenceofanalogueregisters
onaremotedevice.Theslaveaddress,thestartingregisteraddress,theregistervalues,
andthesignatureofthedatamustbespecified.Theaddressofthefirstregisteris0anda
maximumof125registervaluescanbewritten.ThePythonsamplecodeisshownbelow.
slave_addr=0x0A
register_address=0x01
register_values=[2,-4,6,-256,1024]
signed=True
return_flag=modbus_obj.write_multiple_registers(slave_addr,register_address,regist
er_values,signed)
output_flag='Success'ifreturn_flagelse'Failure'
print('Writingmultipleregisterstatus:'+output_flag)
4.2.14Modbus
188
Overview
Pycommodulescomewiththeabilitytoupdatethedevicesfirmware,whileitisstillrunning,
wecallthisan"overtheair"(OTA)update.Thepycomlibraryprovidesseveralfunctionsto
achievethis.Thisexamplewilldemonstratehowyoucouldpotentiallyusethisfunctionality
toupdatedeployeddevices.Thefullsourcecodeofthisexamplecanbefoundhere.
Method
Herewewilldescribeonepossibleupdatemethodologyyoucouldusethatisimplemented
bythisexample.
ImagineyouasmartmeteringcompanyandyouwishtorolloutanupdateforyourPycom
basedsmartmeter.ThesemetersusuallysenddatabackviaLoRa.UnfortunatelyLoRa
downlinkmessageshaveaverylimitedsizeandseveralhundredifnotthousandwouldbe
requiredtouploadacompletefirmwareimage.Togetaroundthisyoucanhaveyourdevices
sendingtheirregulardataviaLoRaandwhentheyreceiveaspecialcommandviaa
downlinkmessage,thedeviceswillconnecttoaWiFinetwork.Itisunfeasibletoask
customerstoallowyourdevicetoconnecttotheirhomenetworksoinsteadthisnetwork
couldbeprovidedbyavehicle.Thisvehiclewilltravelaroundacertaingeographicareain
whichthedeviceshavebeensentthespecialdownlinkmessagetoinitiatetheupdate.The
deviceswilllookfortheWiFinetworkbeingbroadcastbythevehicleandconnect.The
deviceswillthenconnecttoaserverrunningonthisWiFinetwork.Thisserver(alsoshown
inthisexample)willgeneratemanifestfilesthatinstructthedeviceonwhatitshouldupdate,
andwheretogettheupdatedatafrom.
Server
Codeavailablehere.
ThisscriptrunsaHTTPserveronport 8000thatprovisionsovertheair(OTA)update
manifestsinJSONformataswellasservingtheupdatecontent.Thisscriptshouldberunin
adirectorythatcontainseveryversionoftheenddevicescode,inthefollowingstructure:
4.2.15OTAupdate
189
-serverdirectory
|-this_script.py
|-1.0.0
||-flash
|||-lib
||||-lib_a.py
|||-main.py
|||-boot.py
||-sd
||-some_asset.txt
||-asset_that_will_be_removed.wav
|-1.0.1
||-flash
|||-lib
||||-lib_a.py
||||-new_lib.py
|||-main.py
|||-boot.py
||-sd
||-some_asset.txt
|-firmware_1.0.0.bin
|-firmware_1.0.1.bin
Thetopleveldirectorythatcontainsthisscriptcancontainoneoftwothings:
Updatedirectory:Theseshouldbenamedwithaversionnumbercompatiblewiththe
pythonLooseVersionversioningscheme
(http://epydoc.sourceforge.net/stdlib/distutils.version.LooseVersion-class.html).They
shouldcontaintheentirefilesystemoftheenddeviceforthecorrespondingversion
number.
Firmware:Thesefilesshouldbenamedintheformat firmare_VERSION.bin,where
VERSIONisaaversionnumbercompatiblewiththepythonLooseVersionversioning
scheme(http://epydoc.sourceforge.net/stdlib/distutils.version.LooseVersion-class.html).
Thisfileshouldbeintheformatofthe appimg.bincreatedbythePycomfirmwarebuild
scripts.
Howtouse
Oncethedirectoryhasbeensetupasdescribedaboveyousimplyneedtostartthisscript
usingpython3.OncestartedthisscriptwillrunaHTTPserveronport 8000(thiscanbe
changedbychangingthePORTvariable).Thisserverwillserveallthefilesindirectoryas
expectedalongwithoneadditionalspecialfile, manifest.json.Thisfiledoesnotexiston
4.2.15OTAupdate
190
thefilesystembutisinsteadgeneratedwhenrequestedandcontainstherequiredchanges
tobringtheenddevicefromitscurrentversiontothelatestavailableversion.Youcansee
anexampleofthisbypointingyourwebbrowserat:
http://127.0.0.1:8000/manifest.json?current_ver=1.0.0
The current_verfieldattheendoftheURLshouldbesettothecurrentfirmwareversionof
theenddevice.Thegeneratedmanifestwillcontainlistsofwhichfilesarenew,have
changedorneedtobedeletedalongwithSHA1hashesofthefiles.Belowisanexampleof
whatsuchamanifestmightlooklike:
{
"delete":[
"flash/old_file.py",
"flash/other_old_file.py"
],
"firmware":{
"URL":"http://192.168.1.144:8000/firmware_1.0.1b.bin",
"hash":"ccc6914a457eb4af8855ec02f6909316526bdd08"
},
"new":[
{
"URL":"http://192.168.1.144:8000/1.0.1b/flash/lib/new_lib.py",
"dst_path":"flash/lib/new_lib.py",
"hash":"1095df8213aac2983efd68dba9420c8efc9c7c4a"
}
],
"update":[
{
"URL":"http://192.168.1.144:8000/1.0.1b/flash/changed_file.py",
"dst_path":"flash/changed_file.py",
"hash":"1095df8213aac2983efd68dba9420c8efc9c7c4a"
}
],
"version":"1.0.1b"
}
Themanifestcontainsthefollowingfields:
delete:Alistofpathstofileswhicharenolongerneeded
firmware:TheURLandSHA1hashofthefirmwareimage
new:theURL,pathonenddeviceandSHA1hashofallnewfiles
update:theURL,pathonenddeviceandSHA1hashofallfileswhichexistedbefore
buthavechanged.
version:Theversionnumberthatthismanifestwillupdatetheclientto
previous_version:Theversiontheclientiscurrentlyonbeforeapplyingthisupdate
4.2.15OTAupdate
191
Note:Theversionnumberofthefilesmightnotbethesameasthefirmware.Thehighest
availableversionnumber,higherthanthecurrentclientversionisusedforbothfirmwareand
files.Thismaydifferbetweenthetwo.
InorderfortheURL'stobeproperlyformattedyouarerequiredtosenda"host"header
alongwithyourHTTPgetrequeste.g:
GET/manifest.json?current_ver=1.0.0HTTP/1.0\r\nHost:192.168.1.144:8000\r\n\r\n
ClientLibrary
AMicroPytonlibraryforinterfacingwiththeserverdescribedaboveisavailablehere.
Thislibraryissplitintotwolayers.Thetoplevel OTAclassimplementsallthehighlevel
functionalitysuchasparsingtheJSONfile,makingbackcopiesoffilesbeingupdated
incasetheupdatefails,etc.Thelayerofthelibraryisagnostictoyourchosentransport
method.Belowthisisthe WiFiOTAclass.Thisclassimplementstheactualtransport
mechanismofhowthedevicefetchesthefilesandupdatemanifest(viaWiFiastheclass
namesuggests).Thereasonforthissplitissothatthehighlevelfunctionalitycanbereused
regardlessofwhattransportmechanismyouendupusing.Thiscouldbeimplementedon
topofBluetoothforexample,ortheseverchangedfromHTTPtoFTP.
Althoughtheabovecodeisfunctional,itisprovidedonlyasanexampleofhowanend
usermightimplementaOTAupdatemechanism.Itisnot100%featurecompletee.g.
eventhoughitdoesbackuppreviousversionsoffiles,therollbackprocedureisnot
implemented.Thisisleftoftheendusertodo.
Example
Belowisamexampleimplementingthemethodologypreviouslyexplainedinthistutorialto
initiateanOTAupdate.
TheexamplebelowwillonlyworkonaPycomdevicewithLoRacapabilities.Ifwantto
testitoutonadevicewithoutLoRafunctionalitythensimplycommentoutanycode
relatingtoLoRa.Leavingjustthe WiFiOTAinitialisationandthey ota.connect()and
ota.update()
4.2.15OTAupdate
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fromnetworkimportLoRa,WLAN
importsocket
importtime
fromOTAimportWiFiOTA
fromtimeimportsleep
importpycom
importubinascii
fromconfigimportWIFI_SSID,WIFI_PW,SERVER_IP
#TurnonGREENLED
pycom.heartbeat(False)
pycom.rgbled(0xff00)
#SetupOTA
ota=WiFiOTA(WIFI_SSID,
WIFI_PW,
SERVER_IP,#Updateserveraddress
8000)#Updateserverport
#TurnoffWiFitosavepower
w=WLAN()
w.deinit()
#InitialiseLoRainLORAWANmode.
lora=LoRa(mode=LoRa.LORAWAN,region=LoRa.EU868)
app_eui=ubinascii.unhexlify('70B3D57ED0008CD6')
app_key=ubinascii.unhexlify('B57F36D88691CEC5EE8659320169A61C')
#joinanetworkusingOTAA(OvertheAirActivation)
lora.join(activation=LoRa.OTAA,auth=(app_eui,app_key),timeout=0)
#waituntilthemodulehasjoinedthenetwork
whilenotlora.has_joined():
time.sleep(2.5)
print('Notyetjoined...')
#createaLoRasocket
s=socket.socket(socket.AF_LORA,socket.SOCK_RAW)
#settheLoRaWANdatarate
s.setsockopt(socket.SOL_LORA,socket.SO_DR,5)
#makethesocketblocking
#(waitsforthedatatobesentandforthe2receivewindowstoexpire)
s.setblocking(True)
whileTrue:
#sendsomedata
s.send(bytes([0x04,0x05,0x06]))
4.2.15OTAupdate
193
#makethesocketnon-blocking
#(becauseifthere'snodatareceiveditwillblockforever...)
s.setblocking(False)
#getanydatareceived(ifany...)
data=s.recv(64)
#SomesortofOTAtrigger
ifdata==bytes([0x01,0x02,0x03]):
print("PerformingOTA")
#PerformOTA
ota.connect()
ota.update()
sleep(5)
4.2.15OTAupdate
194
RMT
Detailedinformationaboutthisclasscanbefoundin RMT.
TheRMT(RemoteControl)peripheraloftheESP32isprimarilydesignedtosendand
receiveinfraredremotecontrolsignalsthatuseon-off-keyingofacarrierfrequency,butdue
toitsdesignitcanbeusedtogeneratevarioustypesofsignals,thisclasswillallowyouto
dothis.
TheRMThas7channels,ofwhich5areavailableandcanbemappedtoanyGPIOpin
(Note:Pins P13- P18canonlybeusedasinputs).
Channel Resolution MaximumPulseWidth
0 Usedbyon-boardLED
1 Usedby pycom.pulses_get()
2 100nS 3.2768ms
3 100nS 3.2768ms
4 1000nS 32.768ms
5 1000nS 32.768ms
6 3125nS 102.4ms
7 3125nS 102.4ms
Transmitting
ThefollowingexamplescreateanRMTobjectonchannel4,configureitfortransmission
andsendsomedatainvariousforms.Theresolutionofchannel4is1000nanoseconds,the
givenvaluesareinterpretedaccordingly.
Inthisfirstexample,wedefinethesignalasatupleofbinaryvaluesthatdefinetheshapeof
thedesiredsignalalongwiththedurationofabit.
4.2.16RMT
195
frommachineimportRMT
#MapRMTchannel4toP21,whentheRMTisidle,itwilloutputLOW
rmt=RMT(channel=4,gpio="P21",tx_idle_level=RMT.LOW)
#Producesthepatternshownindata,whereeachbitlasts
#duration*channelresolution=10000*1000ns=10ms
data=(1,0,1,1,1,0,1,0,1)
duration=10000
rmt.pulses_send(duration,data)
Inthisexamplewedefinethesignalbyatupleofdurationsandwhatstatethesignalstarts
in.
frommachineimportRMT
#MapRMTchannel4toP21,whentheRMTisidle,itwilloutputLOW
rmt=RMT(channel=4,gpio="P21",tx_idle_level=RMT.LOW)
#Thelistofdurationsforeachpulsetobe,theseareinunitsofthechannels
#resolution:
#duration=Desiredpulselength/ChannelResolution
duration=(8000,11000,8000,11000,6000,13000,6000,3000,8000)
#`start_level`definesifthesignalstartsoffasLOWorHIGH,itwillthen
#togglestatebetweeneachduration
rmt.pulses_send(duration,start_level=RMT.HIGH)
4.2.16RMT
196
Thisthirdexample,isacombinationoftheabovetwostylesofdefiningasignal.Eachpulse
hasadefineddurationaswellasastate.Thisisusefulifyoudon'talwayswantthesignalto
togglestate.
frommachineimportRMT
#MapRMTchannel4toP21,whentheRMTisidle,itwilloutputLOW
rmt=RMT(channel=4,gpio="P21",tx_idle_level=RMT.LOW)
#Producesthepatternshownindata,whereeachbitlasts
#duration[i]*channelresolution=duration[i]*1000ns
data=(1,0,1,1,0,1)
duration=(400,200,100,300,200,400)
rmt.pulses_send(duration,data)
ThefollowingexamplecreatesanRMTobjectonchannel4andconfiguresitfor
transmissionwithcarriermodulation.
frommachineimportRMT
rmt=RMT(channel=4,
gpio="P21",
tx_idle_level=RMT.LOW,
#Carrier=100Hz,80%duty,modulesHIGHsignals
tx_carrier=(100,70,RMT.HIGH))
data=(1,0,1)
duration=10000
rmt.pulses_send(duration,data)
4.2.16RMT
197
ThefollowingexamplecreatesanRMTobjectonchannel2,configuresitforreceiving,then
waitsforthefirst,undefinednumberofpulseswithouttimeout
frommachineimportRMT
rmt=machine.RMT(channel=2)
rmt.init(gpio="P21",rx_idle_threshold=1000)
data=rmt.pulses_get()
If tx_idle_levelisnotsettotheoppositeofthethirdvalueinthe tx_carriertuple,
thecarrierwavewillcontinuetobegeneratedwhentheRMTchannelisidle.
Receiving
ThefollowingexamplecreatesanRMTobjectonchannel2,configuresitforreceivinga
undefinednumberofpulses,thenwaitsmaximumof1000usforthefirstpulse.
frommachineimportRMT
#SetsRMTchannel2toP21andsetsthemaximumlengthofavalidpulseto
#1000*channelresolution=1000*100ns=100us
rmt=machine.RMT(channel=2,gpio="P21",rx_idle_threshold=1000)
rmt.init()
#Getaundefinednumberofpulses,waitingamaximumof500usforthefirst
#pulse(unlikeotherplaceswheretheabsolutedurationwasbasedontheRMT
#channelsresolution,thisvalueisinus)untilapulselongerthan
#rx_idle_thresholdoccurs.
data=rmt.pulses_get(timeout=500)
ThefollowingexamplecreatesanRMTobjectonchannel2,configuresitforreceiving,filters
outpulseswithwidth<20*100nanoseconds,thenwaitsfor100pulses
4.2.16RMT
198
frommachineimportRMT
rmt=machine.RMT(channel=2,#Resolution=100ns
gpio="P21",
#Longestvalidpulse=1000*100ns=100us
rx_idle_threshold=1000,
#Filteroutpulsesshorterthan20*100ns=2us
rx_filter_threshold=20)
#Receive100pulses,pulsesshorterthan2usorlongerthan100uswillbe
#ignored.Thatmeansifitreceives80validpulsesbutthenthesignal
#doesn'tchangefor10hoursandthen20morepulsesoccur,thisfunction
#willwaitfor10h
data=rmt.pulses_get(pulses=100)
4.2.16RMT
199
LoPyTutorials
ThefollowingtutorialsdemonstratetheuseoftheLoRafunctionalityontheLoPy.LoRacan
workin2differentmodes;LoRa-MAC(whichwealsocallRaw-LoRa)andLoRaWANmode.
LoRa-MACmodebasicallyaccessesderadiodirectlyandpacketsaresentusingtheLoRa
modulationontheselectedfrequencywithoutanyheaders,addressinginformationor
encryption.OnlyaCRCisaddedatthetailofthepacketandthisisremovedbeforethe
receivedframeispassedontotheapplication.Thismodecanbeusedtobuildanyhigher
levelprotocolthatcanbenefitfromthelongrangefeaturesoftheLoRamodulation.Typical
usescasesincludeLoPytoLoPydirectcommunicationandaLoRapacketforwarder.
LoRaWANmodeimplementsthefullLoRaWANstackforaclassAdevice.Itsupportsboth
OTAAandABPconnectionmethods,aswellasadvancedfeatureslikeaddingandremoving
customchannelstosupport"special"frequenciesplanslikethethoseusedinNewZealand.
4.3LoRaExamples
200
LoRa-MAC(RawLoRa)
BasicLoRaconnectionexample,sendingandreceivingdata.InLoRa-MACmodethe
LoRaWANlayerisbypassedandtheradioisuseddirectly.Thedatasentisnotformattedor
encryptedinanyway,andnoaddressinginformationisaddedtotheframe.
Fortheexamplebelow,youwillneedtwoLoPys.Awhileloopwitharandomdelaytimeis
usedtominimisethechancesofthe2LoPy’stransmittingatthesametime.Runthecode
belowonthe2LoPymodulesandyouwillseetheword'Hello'beingreceivedonbothsides.
fromnetworkimportLoRa
importsocket
importmachine
importtime
#initialiseLoRainLORAmode
#Pleasepicktheregionthatmatcheswhereyouareusingthedevice:
#Asia=LoRa.AS923
#Australia=LoRa.AU915
#Europe=LoRa.EU868
#UnitedStates=LoRa.US915
#moreparamscanalsobegiven,likefrequency,txpowerandspreadingfactor
lora=LoRa(mode=LoRa.LORA,region=LoRa.EU868)
#createarawLoRasocket
s=socket.socket(socket.AF_LORA,socket.SOCK_RAW)
whileTrue:
#sendsomedata
s.setblocking(True)
s.send('Hello')
#getanydatareceived...
s.setblocking(False)
data=s.recv(64)
print(data)
#waitarandomamountoftime
time.sleep(machine.rng()&0x0F)
4.3.1LoRa-MAC(RawLoRa)
201
LoRaWAN(OTAA)
OTAAstandsforOverTheAirAuthentication.WiththismethodtheLoPysendsaJoin
requesttotheLoRaWANGatewayusingthe APPEUIand APPKEYprovided.Ifthekeysare
correcttheGatewaywillreplytotheLoPywithajoinacceptmessageandfromthatpointon
theLoPyisabletosendandreceivepacketsto/fromtheGateway.Ifthekeysareincorrect
noresponsewillbereceivedandthe has_joined()methodwillalwaysreturn False.
Theexamplebelowattemptstogetanydatareceivedaftersendingtheframe.Keepinmind
thattheGatewaymightnotbesendinganydataback,thereforewemakethesocketnon-
blockingbeforeattemptingtoreceive,inordertopreventgettingstuckwaitingforapacket
thatwillneverarrive.
4.3.2LoRaWANwithOTAA
202
fromnetworkimportLoRa
importsocket
importtime
importubinascii
#InitialiseLoRainLORAWANmode.
#Pleasepicktheregionthatmatcheswhereyouareusingthedevice:
#Asia=LoRa.AS923
#Australia=LoRa.AU915
#Europe=LoRa.EU868
#UnitedStates=LoRa.US915
lora=LoRa(mode=LoRa.LORAWAN,region=LoRa.EU868)
#createanOTAAauthenticationparameters
app_eui=ubinascii.unhexlify('ADA4DAE3AC12676B')
app_key=ubinascii.unhexlify('11B0282A189B75B0B4D2D8C7FA38548B')
#joinanetworkusingOTAA(OvertheAirActivation)
lora.join(activation=LoRa.OTAA,auth=(app_eui,app_key),timeout=0)
#waituntilthemodulehasjoinedthenetwork
whilenotlora.has_joined():
time.sleep(2.5)
print('Notyetjoined...')
#createaLoRasocket
s=socket.socket(socket.AF_LORA,socket.SOCK_RAW)
#settheLoRaWANdatarate
s.setsockopt(socket.SOL_LORA,socket.SO_DR,5)
#makethesocketblocking
#(waitsforthedatatobesentandforthe2receivewindowstoexpire)
s.setblocking(True)
#sendsomedata
s.send(bytes([0x01,0x02,0x03]))
#makethesocketnon-blocking
#(becauseifthere'snodatareceiveditwillblockforever...)
s.setblocking(False)
#getanydatareceived(ifany...)
data=s.recv(64)
print(data)
4.3.2LoRaWANwithOTAA
203
LoRaWAN(ABP)
ABPstandsforAuthenticationByPersonalisation.Itmeansthattheencryptionkeysare
configuredmanuallyonthedeviceandcanstartsendingframestotheGatewaywithout
needinga'handshake'proceduretoexchangethekeys(suchastheoneperformedduring
anOTAAjoinprocedure).
Theexamplebelowattemptstogetanydatareceivedaftersendingtheframe.Keepinmind
thattheGatewaymightnotbesendinganydataback,thereforewemakethesocketnon-
blockingbeforeattemptingtoreceive,inordertopreventgettingstuckwaitingforapacket
thatwillneverarrive.
4.3.3LoRaWANwithABP
204
fromnetworkimportLoRa
importsocket
importubinascii
importstruct
#InitialiseLoRainLORAWANmode.
#Pleasepicktheregionthatmatcheswhereyouareusingthedevice:
#Asia=LoRa.AS923
#Australia=LoRa.AU915
#Europe=LoRa.EU868
#UnitedStates=LoRa.US915
lora=LoRa(mode=LoRa.LORAWAN,region=LoRa.EU868)
#createanABPauthenticationparams
dev_addr=struct.unpack(">l",binascii.unhexlify('00000005'))[0]
nwk_swkey=ubinascii.unhexlify('2B7E151628AED2A6ABF7158809CF4F3C')
app_swkey=ubinascii.unhexlify('2B7E151628AED2A6ABF7158809CF4F3C')
#joinanetworkusingABP(ActivationByPersonalization)
lora.join(activation=LoRa.ABP,auth=(dev_addr,nwk_swkey,app_swkey))
#createaLoRasocket
s=socket.socket(socket.AF_LORA,socket.SOCK_RAW)
#settheLoRaWANdatarate
s.setsockopt(socket.SOL_LORA,socket.SO_DR,5)
#makethesocketblocking
#(waitsforthedatatobesentandforthe2receivewindowstoexpire)
s.setblocking(True)
#sendsomedata
s.send(bytes([0x01,0x02,0x03]))
#makethesocketnon-blocking
#(becauseifthere'snodatareceiveditwillblockforever...)
s.setblocking(False)
#getanydatareceived(ifany...)
data=s.recv(64)
print(data)
4.3.3LoRaWANwithABP
205
LoRaNano-Gateway(RawLoRa)
ThisexampleallowsarawLoRaconnectionbetweentwoLoPys(nodes)toasingleLoPy
actingasaNano-Gateway.
Formoreinformationanddiscussionsaboutthiscode,seethisforumpost.
GatewayCode
importsocket
importstruct
fromnetworkimportLoRa
#Abasicpackageheader,B:1byteforthedeviceId,B:1byteforthepkgsize,%ds:
Formattedstringforstring
_LORA_PKG_FORMAT="!BB%ds"
#Abasicackpackage,B:1byteforthedeviceId,B:1byteforthepkgsize,B:1by
tefortheOk(200)orerrormessages
_LORA_PKG_ACK_FORMAT="BBB"
#OpenaLoRaSocket,userx_iqtoavoidlisteningtoourownmessages
#Pleasepicktheregionthatmatcheswhereyouareusingthedevice:
#Asia=LoRa.AS923
#Australia=LoRa.AU915
#Europe=LoRa.EU868
#UnitedStates=LoRa.US915
lora=LoRa(mode=LoRa.LORA,rx_iq=True,region=LoRa.EU868)
lora_sock=socket.socket(socket.AF_LORA,socket.SOCK_RAW)
lora_sock.setblocking(False)
while(True):
recv_pkg=lora_sock.recv(512)
if(len(recv_pkg)>2):
recv_pkg_len=recv_pkg[1]
device_id,pkg_len,msg=struct.unpack(_LORA_PKG_FORMAT%recv_pkg_len,recv_
pkg)
#Iftheuart=machine.UART(0,115200)andos.dupterm(uart)aresetintheboot.pyth
isprintshouldappearintheserialport
print('Device:%d-Pkg:%s'%(device_id,msg))
ack_pkg=struct.pack(_LORA_PKG_ACK_FORMAT,device_id,1,200)
lora_sock.send(ack_pkg)
4.3.4LoRa-MACNano-Gateway
206
The _LORA_PKG_FORMATisusedasamethodofidentifyingthedifferentdeviceswithina
network.The _LORA_PKG_ACK_FORMATisasimple ackpackageasaresponsetothenodes
package.
Node
4.3.4LoRa-MACNano-Gateway
207
importos
importsocket
importtime
importstruct
fromnetworkimportLoRa
#Abasicpackageheader,B:1byteforthedeviceId,B:1byteforthepkgsize
_LORA_PKG_FORMAT="BB%ds"
_LORA_PKG_ACK_FORMAT="BBB"
DEVICE_ID=0x01
#OpenaLoraSocket,usetx_iqtoavoidlisteningtoourownmessages
#Pleasepicktheregionthatmatcheswhereyouareusingthedevice:
#Asia=LoRa.AS923
#Australia=LoRa.AU915
#Europe=LoRa.EU868
#UnitedStates=LoRa.US915
lora=LoRa(mode=LoRa.LORA,tx_iq=True,region=LoRa.EU868)
lora_sock=socket.socket(socket.AF_LORA,socket.SOCK_RAW)
lora_sock.setblocking(False)
while(True):
#Packagesendcontainingasimplestring
msg="Device1Here"
pkg=struct.pack(_LORA_PKG_FORMAT%len(msg),DEVICE_ID,len(msg),msg)
lora_sock.send(pkg)
#Waitfortheresponsefromthegateway.NOTE:Forthisdemothedevicedoesani
nfiniteloopforwhilewaitingtheresponse.Introduceamax_time_waitingforyouappl
ication
waiting_ack=True
while(waiting_ack):
recv_ack=lora_sock.recv(256)
if(len(recv_ack)>0):
device_id,pkg_len,ack=struct.unpack(_LORA_PKG_ACK_FORMAT,recv_ack)
if(device_id==DEVICE_ID):
if(ack==200):
waiting_ack=False
#Iftheuart=machine.UART(0,115200)andos.dupterm(uart)ares
etintheboot.pythisprintshouldappearintheserialport
print("ACK")
else:
waiting_ack=False
#Iftheuart=machine.UART(0,115200)andos.dupterm(uart)ares
etintheboot.pythisprintshouldappearintheserialport
print("MessageFailed")
time.sleep(5)
4.3.4LoRa-MACNano-Gateway
208
Thenodeisalwayssendingpackagesandwaitingforthe ackfromthegateway.
Toadaptthiscodetouserspecificneeds:
Putamaxwaitingtimeforthe acktoarriveandresendthepackageormarkitas
invalid
Increasethepackagesizechangingthe _LORA_PKG_FORMATto BH%ds.The Hwill
allowthekeepingof2bytesforsize(formoreinformationaboutstructformat)
Reducethepackagesizewithbitwisemanipulation
Reducethemessagesize(forthisdemo,astring)tosomethingmoreusefulfor
specificdevelopment
4.3.4LoRa-MACNano-Gateway
209
LoRaModuletoModuleConnection
ThisexampleshowshowtoconnecttwoPycodeLoRacapablemodules(nodes)viaraw
LoRa.
NodeA
fromnetworkimportLoRa
importsocket
importtime
#Pleasepicktheregionthatmatcheswhereyouareusingthedevice:
#Asia=LoRa.AS923
#Australia=LoRa.AU915
#Europe=LoRa.EU868
#UnitedStates=LoRa.US915
lora=LoRa(mode=LoRa.LORA,region=LoRa.EU868)
s=socket.socket(socket.AF_LORA,socket.SOCK_RAW)
s.setblocking(False)
whileTrue:
ifs.recv(64)==b'Ping':
s.send('Pong')
time.sleep(5)
NodeB
fromnetworkimportLoRa
importsocket
importtime
#Pleasepicktheregionthatmatcheswhereyouareusingthedevice:
#Asia=LoRa.AS923
#Australia=LoRa.AU915
#Europe=LoRa.EU868
#UnitedStates=LoRa.US915
lora=LoRa(mode=LoRa.LORA,region=LoRa.EU868)
s=socket.socket(socket.AF_LORA,socket.SOCK_RAW)
s.setblocking(False)
whileTrue:
s.send('Ping')
time.sleep(5)
4.3.5LoPytoLoPy
210
4.3.5LoPytoLoPy
211
LoRaWANNano-Gateway
ThisexampleallowstoconnectaLoPytoaLoRaWANnetworksuchasTheThingsNetwork
(TTN)orLoriottobeusedasanano-gateway.
ThisexampleusessettingsspecificallyforconnectingtoTheThingsNetworkwithinthe
European868MHzregion.Foranotherusage,pleaseseethe config.pyfileforrelevant
sectionsthatneedchanging.
UptodateversionsofthesesnippetscanbefoundatthefollowingGitHubRepository.For
moreinformationanddiscussionaboutthiscode,seethisforumpost.
Nano-Gateway
TheNano-Gatewaycodeissplitinto3files, main.py, config.pyand nanogateway.py.
Theseareusedtoconfigureandspecifyhowthegatewaywillconnecttoapreferred
networkandhowitcanactaspacketforwarder.
GatewayID
MostLoRaWANnetworkserversexpectaGatewayIDintheformofaunique64-bit
hexadecimalnumber(calledaEUI-64).TherecommendedpracticeistoproducethisID
fromyourboardbyexpandingtheWiFiMACaddress(a48-bitnumber,calledMAC-48).You
canobtainthatbyrunningthiscodepriortoconfiguration:
fromnetworkimportWLAN
importubinascii
wl=WLAN()
ubinascii.hexlify(wl.mac())[:6]+'FFFE'+ubinascii.hexlify(wl.mac())[6:]
Theresultwillbysomethinglike b'240ac4FFFE008d88'where 240ac4FFFE008d88isyour
GatewayIDtobeusedinyournetworkproviderconfiguration.
Main( main.py)
Thisfilerunsatbootandcallsthelibraryand config.pyfilestoinitialisethenano-gateway.
Onceconfigurationisset,thenano-gatewayisthenstarted.
4.3.6LoRaWANNano-Gateway
212
"""LoPyLoRaWANNanoGatewayexampleusage"""
importconfig
fromnanogatewayimportNanoGateway
if__name__=='__main__':
nanogw=NanoGateway(
id=config.GATEWAY_ID,
frequency=config.LORA_FREQUENCY,
datarate=config.LORA_GW_DR,
ssid=config.WIFI_SSID,
password=config.WIFI_PASS,
server=config.SERVER,
port=config.PORT,
ntp_server=config.NTP,
ntp_period=config.NTP_PERIOD_S
)
nanogw.start()
nanogw._log('YoumaynowpressENTERtoentertheREPL')
input()
Configuration( config.py)
Thisfilecontainssettingsfortheserverandnetworkitisconnectingto.Dependingonthe
nano-gatewayregionandprovider(TTN,Loriot,etc.)thesewillvary.Theprovidedexample
willworkwithTheThingsNetwork(TTN)intheEuropean,868Mhz,region.
TheGatewayIDisgeneratedinthescriptusingtheprocessdescribedabove.
PleasechangetheWIFI_SSIDandWIFI_PASSvariablestomatchyourdesiredWiFi
network
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"""LoPyLoRaWANNanoGatewayconfigurationoptions"""
importmachine
importubinascii
WIFI_MAC=ubinascii.hexlify(machine.unique_id()).upper()
#SettheGatewayIDtobethefirst3bytesofMACaddress+'FFFE'+last3byteso
fMACaddress
GATEWAY_ID=WIFI_MAC[:6]+"FFFE"+WIFI_MAC[6:12]
SERVER='router.eu.thethings.network'
PORT=1700
NTP="pool.ntp.org"
NTP_PERIOD_S=3600
WIFI_SSID='my-wifi'
WIFI_PASS='my-wifi-password'
#forEU868
LORA_FREQUENCY=868100000
LORA_GW_DR="SF7BW125"#DR_5
LORA_NODE_DR=5
#forUS915
#LORA_FREQUENCY=903900000
#LORA_GW_DR="SF7BW125"#DR_3
#LORA_NODE_DR=3
Library( nanogateway.py)
Thenano-gatewaylibrarycontrolsallofthepacketgenerationandforwardingfortheLoRa
data.Thisdoesnotrequireanyuserconfigurationandthelatestversionofthiscodeshould
bedownloadedfromthePycomGitHubRepository.
"""LoPyNanoGatewayclass"""
fromnetworkimportWLAN
fromnetworkimportLoRa
frommachineimportTimer
importos
importubinascii
importmachine
importjson
importtime
importerrno
import_thread
importsocket
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PROTOCOL_VERSION=const(2)
PUSH_DATA=const(0)
PUSH_ACK=const(1)
PULL_DATA=const(2)
PULL_ACK=const(4)
PULL_RESP=const(3)
TX_ERR_NONE="NONE"
TX_ERR_TOO_LATE="TOO_LATE"
TX_ERR_TOO_EARLY="TOO_EARLY"
TX_ERR_COLLISION_PACKET="COLLISION_PACKET"
TX_ERR_COLLISION_BEACON="COLLISION_BEACON"
TX_ERR_TX_FREQ="TX_FREQ"
TX_ERR_TX_POWER="TX_POWER"
TX_ERR_GPS_UNLOCKED="GPS_UNLOCKED"
STAT_PK={"stat":{"time":"","lati":0,
"long":0,"alti":0,
"rxnb":0,"rxok":0,
"rxfw":0,"ackr":100.0,
"dwnb":0,"txnb":0}}
RX_PK={"rxpk":[{"time":"","tmst":0,
"chan":0,"rfch":0,
"freq":868.1,"stat":1,
"modu":"LORA","datr":"SF7BW125",
"codr":"4/5","rssi":0,
"lsnr":0,"size":0,
"data":""}]}
TX_ACK_PK={"txpk_ack":{"error":""}}
classNanoGateway:
def__init__(self,id,frequency,datarate,ssid,password,server,port,ntp='poo
l.ntp.org',ntp_period=3600):
self.id=id
self.frequency=frequency
self.sf=self._dr_to_sf(datarate)
self.ssid=ssid
self.password=password
self.server=server
self.port=port
self.ntp=ntp
self.ntp_period=ntp_period
self.rxnb=0
self.rxok=0
self.rxfw=0
self.dwnb=0
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self.txnb=0
self.stat_alarm=None
self.pull_alarm=None
self.uplink_alarm=None
self.udp_lock=_thread.allocate_lock()
self.lora=None
self.lora_sock=None
defstart(self):
#ChangeWiFitoSTAmodeandconnect
self.wlan=WLAN(mode=WLAN.STA)
self._connect_to_wifi()
#GetatimeSync
self.rtc=machine.RTC()
self.rtc.ntp_sync(self.ntp,update_period=self.ntp_period)
#GettheserverIPandcreateanUDPsocket
self.server_ip=socket.getaddrinfo(self.server,self.port)[0][-1]
self.sock=socket.socket(socket.AF_INET,socket.SOCK_DGRAM,socket.IPPROTO_UD
P)
self.sock.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR,1)
self.sock.setblocking(False)
#Pushthefirsttimeimmediately
self._push_data(self._make_stat_packet())
#Createthealarms
self.stat_alarm=Timer.Alarm(handler=lambdat:self._push_data(self._make_sta
t_packet()),s=60,periodic=True)
self.pull_alarm=Timer.Alarm(handler=lambdau:self._pull_data(),s=25,perio
dic=True)
#StarttheUDPreceivethread
_thread.start_new_thread(self._udp_thread,())
#InitializeLoRainLORAmode
self.lora=LoRa(mode=LoRa.LORA,frequency=self.frequency,bandwidth=LoRa.BW_1
25KHZ,sf=self.sf,
preamble=8,coding_rate=LoRa.CODING_4_5,tx_iq=True)
#CreatearawLoRasocket
self.lora_sock=socket.socket(socket.AF_LORA,socket.SOCK_RAW)
self.lora_sock.setblocking(False)
self.lora_tx_done=False
self.lora.callback(trigger=(LoRa.RX_PACKET_EVENT|LoRa.TX_PACKET_EVENT),hand
ler=self._lora_cb)
defstop(self):
#TODO:CheckhowtostoptheNTPsync
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#TODO:Createacancelmethodforthealarm
#TODO:killtheUDPthread
self.sock.close()
def_connect_to_wifi(self):
self.wlan.connect(self.ssid,auth=(None,self.password))
whilenotself.wlan.isconnected():
time.sleep(0.5)
print("WiFiconnected!")
def_dr_to_sf(self,dr):
sf=dr[2:4]
ifsf[1]notin'0123456789':
sf=sf[:1]
returnint(sf)
def_sf_to_dr(self,sf):
return"SF7BW125"
def_make_stat_packet(self):
now=self.rtc.now()
STAT_PK["stat"]["time"]="%d-%02d-%02d%02d:%02d:%02dGMT"%(now[0],now[1],
now[2],now[3],now[4],now[5])
STAT_PK["stat"]["rxnb"]=self.rxnb
STAT_PK["stat"]["rxok"]=self.rxok
STAT_PK["stat"]["rxfw"]=self.rxfw
STAT_PK["stat"]["dwnb"]=self.dwnb
STAT_PK["stat"]["txnb"]=self.txnb
returnjson.dumps(STAT_PK)
def_make_node_packet(self,rx_data,rx_time,tmst,sf,rssi,snr):
RX_PK["rxpk"][0]["time"]="%d-%02d-%02dT%02d:%02d:%02d.%dZ"%(rx_time[0],rx
_time[1],rx_time[2],rx_time[3],rx_time[4],rx_time[5],rx_time[6])
RX_PK["rxpk"][0]["tmst"]=tmst
RX_PK["rxpk"][0]["datr"]=self._sf_to_dr(sf)
RX_PK["rxpk"][0]["rssi"]=rssi
RX_PK["rxpk"][0]["lsnr"]=float(snr)
RX_PK["rxpk"][0]["data"]=ubinascii.b2a_base64(rx_data)[:-1]
RX_PK["rxpk"][0]["size"]=len(rx_data)
returnjson.dumps(RX_PK)
def_push_data(self,data):
token=os.urandom(2)
packet=bytes([PROTOCOL_VERSION])+token+bytes([PUSH_DATA])+ubinascii.un
hexlify(self.id)+data
withself.udp_lock:
try:
self.sock.sendto(packet,self.server_ip)
exceptException:
print("PUSHexception")
def_pull_data(self):
token=os.urandom(2)
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packet=bytes([PROTOCOL_VERSION])+token+bytes([PULL_DATA])+ubinascii.un
hexlify(self.id)
withself.udp_lock:
try:
self.sock.sendto(packet,self.server_ip)
exceptException:
print("PULLexception")
def_ack_pull_rsp(self,token,error):
TX_ACK_PK["txpk_ack"]["error"]=error
resp=json.dumps(TX_ACK_PK)
packet=bytes([PROTOCOL_VERSION])+token+bytes([PULL_ACK])+ubinascii.unh
exlify(self.id)+resp
withself.udp_lock:
try:
self.sock.sendto(packet,self.server_ip)
exceptException:
print("PULLRSPACKexception")
def_lora_cb(self,lora):
events=lora.events()
ifevents&LoRa.RX_PACKET_EVENT:
self.rxnb+=1
self.rxok+=1
rx_data=self.lora_sock.recv(256)
stats=lora.stats()
self._push_data(self._make_node_packet(rx_data,self.rtc.now(),stats.time
stamp,stats.sf,stats.rssi,stats.snr))
self.rxfw+=1
ifevents&LoRa.TX_PACKET_EVENT:
self.txnb+=1
lora.init(mode=LoRa.LORA,frequency=self.frequency,bandwidth=LoRa.BW_125K
HZ,
sf=self.sf,preamble=8,coding_rate=LoRa.CODING_4_5,tx_iq=True)
def_send_down_link(self,data,tmst,datarate,frequency):
self.lora.init(mode=LoRa.LORA,frequency=frequency,bandwidth=LoRa.BW_125KHZ,
sf=self._dr_to_sf(datarate),preamble=8,coding_rate=LoRa.CODING
_4_5,
tx_iq=True)
whiletime.ticks_us()<tmst:
pass
self.lora_sock.send(data)
def_udp_thread(self):
whileTrue:
try:
data,src=self.sock.recvfrom(1024)
_token=data[1:3]
_type=data[3]
if_type==PUSH_ACK:
print("Pushack")
elif_type==PULL_ACK:
4.3.6LoRaWANNano-Gateway
218
print("Pullack")
elif_type==PULL_RESP:
self.dwnb+=1
ack_error=TX_ERR_NONE
tx_pk=json.loads(data[4:])
tmst=tx_pk["txpk"]["tmst"]
t_us=tmst-time.ticks_us()-5000
ift_us<0:
t_us+=0xFFFFFFFF
ift_us<20000000:
self.uplink_alarm=Timer.Alarm(handler=lambdax:self._send_d
own_link(ubinascii.a2b_base64(tx_pk["txpk"]["data"]),

tx_pk["txpk"]["tmst"]-10,tx_pk["txpk"]["datr"],

int(tx_pk["txpk"]["freq"]*1000000)),us=t_us)
else:
ack_error=TX_ERR_TOO_LATE
print("Downlinktimestamperror!,t_us:",t_us)
self._ack_pull_rsp(_token,ack_error)
print("Pullrsp")
exceptsocket.timeout:
pass
exceptOSErrorase:
ife.errno==errno.EAGAIN:
pass
else:
print("UDPrecvOSErrorException")
exceptException:
print("UDPrecvException")
#Waitbeforetryingtoreceiveagain
time.sleep(0.025)
RegisteringwithTTN
TosetupthegatewaywithTheThingsNetwork(TTN),navigatetotheirwebsiteand
create/registeranaccount.Enterausernameandanemailaddresstoverifywiththeir
platform.
4.3.6LoRaWANNano-Gateway
219
Onceanaccounthasbeenregistered,thenano-gatewaycanthenberegistered.Todothis,
navigatetotheTTNConsolewebpage.
RegisteringtheGateway
InsidetheTTNConsole,therearetwooptions, applicationsand gateways.Select
gatewaysandthenclickon registergateway.Thiswillallowforthesetupandregistration
ofanewnano-gateway.
4.3.6LoRaWANNano-Gateway
220
OntheRegisterGatewaypage,youwillneedtosetthefollowingsettings:
Theseareuniquetoeachgateway,locationandcountryspecificfrequency.Pleaseverify
thatcorrectsettingsareselectedotherwisethegatewaywillnotconnecttoTTN.
Youneedtotickthe"I'musingthelegacypacketforwarder"toenabletheright
settings.ThisisbecausetheNano-Gatewayusesthe'defacto'standardSemtechUDP
protocol.
4.3.6LoRaWANNano-Gateway
221
Option Value
Protocol PacketForwarder
GatewayEUI UserDefined(mustmatch config.py)
Description UserDefined
FrequencyPlan SelectCountry(e.g.EU-868MHz)
Location UserDefined
AntennaPlacement IndoororOutdoor
TheGatewayEUIshouldmatchyourGatewayIDfromthe config.pyfile.Wesuggestyou
followtheproceduredescribednearthetopofthisdocumenttocreateyourownunique
GatewayID.
Oncethesesettingshavebeenapplied,click RegisterGateway.AGatewayOverviewpage
willappear,withtheconfigurationsettingsshowing.Nextclickonthe GatewaySettingsand
configuretheRouteraddresstomatchthatofthegateway(default:
router.eu.thethings.network).
The Gatewayshouldnowbeconfigured.Next,oneormorenodescannowbeconfiguredto
usethenano-gatewayandTTNapplicationsmaybebuilt.
LoPyNode
4.3.6LoRaWANNano-Gateway
222
TherearetwomethodsofconnectingLoPydevicestothenano-gateway,OvertheAir
Activation(OTAA)andActivationByPersonalisation(ABP).Thecodeandinstructionsfor
registeringthesemethodsareshownbelow,followedbyinstructionforhowtoconnectthem
toanapplicationonTTN.
It’simportantthatthefollowingcodeexamples(alsoonGitHub)areusedtoconnectto
thenano-gatewayasitonlysupportssinglechannelconnections.
OTAA(OverTheAirActivation)
WhentheLoPyconnectsanapplication(viaTTN)usingOTAA,thenetworkconfigurationis
derivedautomaticallyduringahandshakebetweentheLoPyandnetworkserver.Notethat
thenetworkkeysderivedusingtheOTAAmethodologyarespecifictothedeviceandare
usedtoencryptandverifytransmissionsatthenetworklevel.
"""OTAANodeexamplecompatiblewiththeLoPyNanoGateway"""
fromnetworkimportLoRa
importsocket
importubinascii
importstruct
importtime
#InitializeLoRainLORAWANmode.
lora=LoRa(mode=LoRa.LORAWAN)
#createanOTAauthenticationparams
dev_eui=ubinascii.unhexlify('AABBCCDDEEFF7778')#thesesettingscanbefoundfromT
TN
app_eui=ubinascii.unhexlify('70B3D57EF0003BFD')#thesesettingscanbefoundfromT
TN
app_key=ubinascii.unhexlify('36AB7625FE77776881683B495300FFD6')#thesesettingscan
befoundfromTTN
#setthe3defaultchannelstothesamefrequency(mustbebeforesendingtheOTAAjo
inrequest)
lora.add_channel(0,frequency=868100000,dr_min=0,dr_max=5)
lora.add_channel(1,frequency=868100000,dr_min=0,dr_max=5)
lora.add_channel(2,frequency=868100000,dr_min=0,dr_max=5)
#joinanetworkusingOTAA
lora.join(activation=LoRa.OTAA,auth=(dev_eui,app_eui,app_key),timeout=0)
#waituntilthemodulehasjoinedthenetwork
whilenotlora.has_joined():
time.sleep(2.5)
4.3.6LoRaWANNano-Gateway
223
print('Notjoinedyet...')
#removeallthenon-defaultchannels
foriinrange(3,16):
lora.remove_channel(i)
#createaLoRasocket
s=socket.socket(socket.AF_LORA,socket.SOCK_RAW)
#settheLoRaWANdatarate
s.setsockopt(socket.SOL_LORA,socket.SO_DR,5)
#makethesocketnon-blocking
s.setblocking(False)
time.sleep(5.0)
"""Yourowncodecanbewrittenbelow!"""
foriinrange(200):
s.send(b'PKT#'+bytes([i]))
time.sleep(4)
rx=s.recv(256)
ifrx:
print(rx)
time.sleep(6)
ABP(ActivationByPersonalisation)
UsingABPjoinmoderequirestheusertodefinethefollowingvaluesandinputtheminto
boththeLoPyandtheTTNApplication:
DeviceAddress
ApplicationSessionKey
NetworkSessionKey
4.3.6LoRaWANNano-Gateway
224
"""ABPNodeexamplecompatiblewiththeLoPyNanoGateway"""
fromnetworkimportLoRa
importsocket
importubinascii
importstruct
importtime
#InitialiseLoRainLORAWANmode.
lora=LoRa(mode=LoRa.LORAWAN)
#createanABPauthenticationparams
dev_addr=struct.unpack(">l",ubinascii.unhexlify('2601147D'))[0]#thesesettingsca
nbefoundfromTTN
nwk_swkey=ubinascii.unhexlify('3C74F4F40CAE2221303BC24284FCF3AF')#thesesettingsc
anbefoundfromTTN
app_swkey=ubinascii.unhexlify('0FFA7072CC6FF69A102A0F39BEB0880F')#thesesettingsc
anbefoundfromTTN
#joinanetworkusingABP(ActivationByPersonalisation)
lora.join(activation=LoRa.ABP,auth=(dev_addr,nwk_swkey,app_swkey))
#removeallthenon-defaultchannels
foriinrange(3,16):
lora.remove_channel(i)
#setthe3defaultchannelstothesamefrequency
lora.add_channel(0,frequency=868100000,dr_min=0,dr_max=5)
lora.add_channel(1,frequency=868100000,dr_min=0,dr_max=5)
lora.add_channel(2,frequency=868100000,dr_min=0,dr_max=5)
#createaLoRasocket
s=socket.socket(socket.AF_LORA,socket.SOCK_RAW)
#settheLoRaWANdatarate
s.setsockopt(socket.SOL_LORA,socket.SO_DR,5)
#makethesocketnon-blocking
s.setblocking(False)
"""Yourowncodecanbewrittenbelow!"""
foriinrange(200):
s.send(b'PKT#'+bytes([i]))
time.sleep(4)
rx=s.recv(256)
ifrx:
print(rx)
time.sleep(6)
TTNApplications
4.3.6LoRaWANNano-Gateway
225
Nowthatthegateway&nodeshavebeensetup,aTTNApplicationcanbebuilt;i.e.what
happenstotheLoRadataonceitisreceivedbyTTN.Thereareanumberofdifferent
setups/systemsthatcanbeused,howeverthefollowingexampledemonstratestheHTTP
requestintegration.
RegisteringanApplication
Selectingthe ApplicationstabatthetopoftheTTNconsole,willbringupascreenfor
registeringapplications.Clickregisterandanewpage,similartotheonebelow,willopen.
Enteraunique ApplicationIDaswellasaDescription&HandlerRegistration.
NowtheLoPynodesmustberegisteredtosenddatauptothenewApplication.
RegisteringDevices(LoPy)
Toconnectnodestothenano-gateway,devicesneedtobeaddedtotheapplication.Todo
this,navigatetothe Devicestabonthe Applicationhomepageandclickthe Register
Devicebutton.
Inthe RegisterDevicepanel,completetheformsforthe DeviceIDandthe DeviceEUI.
The DeviceIDisuserspecifiedandisuniquetothedeviceinthisapplication.The Device
EUIisalsouserspecifiedbutmustconsistofexactly8bytes,giveninhexadecimal.
4.3.6LoRaWANNano-Gateway
226
Oncethedevicehasbeenadded,changethe ActivationMethodbetween OTAAand ABP
dependingonuserpreference.ThisoptioncanbefoundundertheSettingstab.
AddingApplicationIntegrations
NowthatthedataisarrivingontheTTNBackend,TTNcanbemanagedastowheredata
shouldbedeliveredto.Todothis,usethe IntegrationstabwithinthenewApplication’s
settings.
Uponclicking addintegration,ascreenwith4differentoptionswillappear.Thesehave
variousfunctionalityandmoreinformationaboutthemcanbefoundontheTTN
website/documentation.
Forthisexample,usethe HTTPIntegrationtoforwardtheLoRaWANPacketstoaremote
server/address.
4.3.6LoRaWANNano-Gateway
227
Click HTTPIntegrationtoconnectupanendpointthatcanreceivethedata.
Fortesting,awebsitecalledRequestBinmaybeusedtoreceivethedatathatTTNforwards
(viaPOSTRequest).Tosetthisup,navigatetoRequestBinandclickthe Createa
RequestBin.
CopytheURLthatisgeneratedandpastthisintothe URLformunderthe Application
Settings.
4.3.6LoRaWANNano-Gateway
228
ThisistheaddressthatTTNwillforwarddataonto.AssoonasaLoPystartssending
messages,TTNwillforwardtheseonto RequestBinandtheywillappearattheunique
RequestBinURL.
4.3.6LoRaWANNano-Gateway
229
RN2483toLoPy
ThisexampleshowshowtosenddatabetweenaMicrochipRN2483andaLoPyviaraw
LoRa.
RN2483
macpause
radiosetfreq868000000
radiosetmodlora
radiosetbw250
radiosetsfsf7
radiosetcr4/5
radiosetbw125
radiosetsync12
radiosetprlen8
#Transmitviaradiotx:
radiotx48656c6C6F#(shouldsend‘Hello’)
LoPy
fromnetworkimportLoRa
importsocket
lora=LoRa(mode=LoRa.LORA,frequency=868000000,bandwidth=LoRa.BW_125KHZ,sf=7,prea
mble=8,
coding_rate=LoRa.CODING_4_5,power_mode=LoRa.ALWAYS_ON,
tx_iq=False,rx_iq=False,public=False)
s=socket.socket(socket.AF_LORA,socket.SOCK_RAW)
#Thiskeepslisteningfordata"forever".
while(True):
s.recv(64)
4.3.7RN2483toLoPy
230
SiPyTutorials
ToensureyourdevicehasbeenprovisionedwithDeviceIDandPACnumber,please
updatetothelatestfirmware.
ThefollowingtutorialsdemonstratehowtoregisterandgetstartedwiththeSiPy.TheSiPy
canbeconfiguredforoperationinvariouscountriesbaseduponspecifiedRCZzones(see
the Sigfoxclassformoreinfo).TheSiPysupportsbothuplinkanddownlink Sigfox
messagesaswellasdevicetodevicecommunicationviaitsFSKMode Sigfox.
4.4SigfoxExamples
231
RegisteringwithSigfox
ToensurethedevicehasbeenprovisionedwithDeviceIDandPACnumber,pleaseupdate
tothelatestfirmware.
InordertosendaSigfoxmessage,thedeviceneedtoregisterwiththeSigfoxBackend.
Navigatetohttps://backend.sigfox.com/activatetofindthelistofSigfoxenabled
developmentkits.
Select Pycomtoproceed.
NextchooseaSigfoxOperatorforthecountrywherethedevicewillbeactivated.Findthe
specificcountryandselecttheoperatortocontinue.
4.4.1RegisterDevice
232
Nowneedtoenterthedevice'sDeviceIDandPACnumber.
TheDeviceIDandPACnumberareretrievablethroughacoupleofcommandsviathe
REPL.
fromnetworkimportSigfox
importubinascii
#initaliseSigfoxforRCZ1(YoumayneedadifferentRCZRegion)
sigfox=Sigfox(mode=Sigfox.SIGFOX,rcz=Sigfox.RCZ1)
#printSigfoxDeviceID
print(ubinascii.hexlify(sigfox.id()))
#printSigfoxPACnumber
print(ubinascii.hexlify(sigfox.pac()))
See SigfoxformoreinfoabouttheSigfoxClassandwhich RCZregiontouse.
4.4.1RegisterDevice
233
Oncethedevice'sDeviceIDandPACnumberhavebeenentered,createanaccount.
Providetherequiredinformationincludingemailaddressandclicktocontinue.
AnemailconfirmingthecreationofaSigfoxBackendaccountandthesuccessful
registrationofthedeviceshouldarriveattheusersinbox.
4.4.1RegisterDevice
234
HowToDisengageSequenceNumber
IfyourareexperiencingissueswithSigfoxconnectivity,thiscouldbeduetothesequence
numberbeingoutofsync.Topreventreplayonthenetwork,theSigfoxprotocoluses
sequencenumbers.Ifthereisalargedifferencebetweenthesequencenumbersentbythe
deviceandtheoneexpectedbythebackend,yourmessageisdroppedbythenetwork.
Youcanusethe Disengagesequencenumberbuttononthedeviceinformationoronthe
devicetypeinformationpageoftheSigfoxbackendtoresetthenumberexpectedbythe
backend.Ifthesequencenumberofyournextmessageisdifferentfromthelasttrashed
sequencenumber,themessagewillbeaccepted.
Issueswiththesequencenumbercanoccurwhenalotofmessagesaresentwhenoutside
ofSigfoxcoverageforinstance.
FirstlyyouwillneedtologintotheSigfoxBackend,navigatetodevice,andclickonthe
SigfoxIDoftheaffectedSiPy.
YoushouldnowseetheInformationpagewithanentry DeviceType:followedbyalink.
Pleasefollowthelink
4.4.2DisengageSequenceNumber
235
Finally,onthispageclickon Disengagesequencenumberbuttonintheupperrightcorner.
4.4.2DisengageSequenceNumber
236
LTETutorials
ThefollowingtutorialsdemonstratetheuseoftheLTECAT-M1andNB-IoTfunctionalityon
cellularenabledPycommodules.
OurcellularmodulessupportbothLTECAT-M1andNB-IoT,thesearenewlowerpower,
longrange,cellularprotocols.Thesearenotthesameasthefullversionof2G/3G/LTE
supportedbycellphones,andrequireyourlocalcarrierstosupportthem.Atthetimeof
writing,CAT-M1andNB-IoTconnectivityisnotwidelyavailablesobesuretocheckwith
localcarriersifsupportisavailablewhereyouare.
4.5LTEExamples
237
LTEclassforCatM1
PleaseensureyouhavethelatestSequansmodemfirmwareforthebestnetwork
compatibility.Instructionsforthiscanbefoundhere.
TheLTECatM1servicegivesfullIPaccessthroughthecellularmodem.
Oncethe lte.connect()functionhascompletedalltheIPsocketfunctions-includingSSL-
willberoutedthroughthisconnection.ThismeananycodeusingWLANcanbeadaptedto
CatM1bysimplyaddingtheconnectionsetupstepfirstanddisconnectafter.
ForexampletoconnectoverLTECatM1toGoogle'swebserveroversecureSSL:
importsocket
importssl
importtime
fromnetworkimportLTE
lte=LTE()#instantiatetheLTEobject
lte.attach()#attachthecellularmodemtoabasestation
whilenotlte.isattached():
time.sleep(0.25)
lte.connect()#startadatasessionandobtainanIPaddress
whilenotlte.isconnected():
time.sleep(0.25)
s=socket.socket()
s=ssl.wrap_socket(s)
s.connect(socket.getaddrinfo('www.google.com',443)[0][-1])
s.send(b"GET/HTTP/1.0\r\n\r\n")
print(s.recv(4096))
s.close()
lte.disconnect()
lte.dettach()
ThisalsoappliestoourMQTTandAWSexamples.
IMPORTANT:OncetheLTEradioisinitialised,itmustbede-initialisedbeforegoingto
deepsleepinordertoensureminimumpowerconsumption.ThisisrequiredduetotheLTE
radiobeingpoweredindependentlyandallowingusecaseswhichrequirethesystemtobe
takenoutfromdeepsleepbyaneventfromtheLTEnetwork(dataorSMSreceivedfor
instance).
4.5.1CAT-M1
238
WhenusingtheexpansionboardandtheFiPytogether,theRTS/CTSjumpersMUSTbe
removedasthosepinsarebeingusedbytheLTEradio.Keepingthosejumpersinplacewill
leadtoerraticoperationandhighercurrentconsumptionspeciallywhileindeepsleep.
4.5.1CAT-M1
239
LTEclassforNarrowBandIoT
Asshipped,PycommodulesonlysupportCAT-M1,inordertouseNB-IoTyouneedto
flashadifferentfirmwaretotheSequansmodem.Instructionsforthiscanbefound
here.
CurrentNB-IoTlimitations
AtthemomenttheNB-IoTfirmwaresuppliedbySequansonlysupportEricssonbase
stationsconfiguredforIn-Bandmode.Standaloneandguard-bandmodeswillbesupported
inalaterrelease.SupportforHuaweibasestationsisalsolimitedandonlylabtestingwith
HuaweieNodeBisrecommendedatthemoment.FullsupportforHuaweiisplannedfor
earlyQ22018.
NB-IoTusage:
ExamplewithVodafone:
fromnetworkimportLTE
lte=LTE()
lte.send_at_cmd('AT+CFUN=0')
lte.send_at_cmd('AT!="clearscanconfig"')
lte.send_at_cmd('AT!="addscanfreqband=20dl-earfcn=6300"')
lte.send_at_cmd('AT!="zsp0:npc1"')
lte.send_at_cmd('AT+CGDCONT=1,"IP","nb.inetd.gdsp"')
lte.send_at_cmd('AT+CFUN=1')
whilenotlte.isattached():
pass
lte.connect()
whilenotlte.isconnected():
pass
#nowusesocketasusual...
4.5.2NB-IoT
240
IMPORTANT:OncetheLTEradioisinitialised,itmustbede-initialisedbeforegoingto
deepsleepinordertoensureminimumpowerconsumption.ThisisrequiredduetotheLTE
radiobeingpoweredindependentlyandallowingusecaseswhichrequirethesystemtobe
takenoutfromdeepsleepbyaneventfromtheLTEnetwork(dataorSMSreceivedfor
instance).
WhenusingtheexpansionboardandtheFiPytogether,theRTS/CTSjumpersMUSTbe
removedasthosepinsarebeingusedbytheLTEradio.Keepingthosejumpersinplacewill
leadtoerraticoperationandhighercurrentconsumptionspeciallywhileindeepsleep.
4.5.2NB-IoT
241
HowtogettheIMEIofyourmodule
InordertoretrievetheIMEIofyourcellularenabledPycommoduleyouwillfirstlyneedto
makesureyouareonfirmwareversion 1.17.0.b1orhigher.Youcancheckyourfirmware
versionbyrunningthefollowingcodeonyoudeviceviatheinteractiveREPL.
>>>importos
>>>os.uname()
(sysname='GPy',nodename='GPy',release='1.17.0.b1',version='v1.8.6-849-d0dc708on20
18-02-27',machine='GPywithESP32')
Onceyouhaveacompatiblefirmware,youcanrunthefollowingcodetogetyourmodules
IMEInumber:
fromnetworkimportLTE
lte=LTE()
lte.send_at_cmd('AT+CGSN=1')
You’llgetareturnstringlikethis \r\n+CGSN:"354347xxxxxxxxx"\r\n\r\nOK.Thevalue
betweenthedoublequotesisyourIMEI.
4.5.3ModuleIMEI
242
FirmwareupgradetoolfortheSequans
MonarchSQN3330
Description
TheSequansMonarchSQN3330cellularradiofoundonthePycomFiPy,GPyandGO1
modulesrequiresadifferentfirmwaretooperateinCAT-M1orNB-IoTmode.
ThispagewillexplaintheprocesstoupgradethefirmwareofthecellularradioTheprocess
involvesstreamingthefirmwarefilefromtheESP32totheSQN3330.Currently,thefilehas
tobestoredinamicroSDcardfirstsothattheESP32canaccessiteasily.Wearecurrent
workingtoaddsupportforstreamingthefileviatheupdatertoolaswell.
Requirements
Beforeproceedingyouwillneed:
Pycomcellularenabledmodule(GPy,FiPy,G01)
FAT32formattedmicroSDcard(withatleast6MBoffreespace)
APycomExpansionBoardorshield(oramicroSDcardsocketbreakoutboard)
Usage
IfyourmoduleisrunningthefactoryLTEchipfirmware,youMUSTfirstperforman
updatetothelatestCAT-M1firmwarebeforetryingtoupgradetotheNB-IoTfirmware.
Skippingthisstepwillcauseyourradiotobecomeunresponsiveanditwillrequire
accesstothetestpointsinordertore-flashthefirmware.
Firstly,youwillneedtodownloadtherequiredlibraryfilesfromhere.Youwillneedtoplace
theseinadirectorycalled"lib"justlikeanyotherlibraries.Thiscanbedoneusingeither
FTPorPymakr
Nextyouneedtodownloadthefirmwarefilefromhere.Youwillneedtoplacethefirmware
onaFAT32formattedmicroSDcard,theninserttheSDcardintoaExpansionBoard,
Pytrack,PysenseorPyscan.Power-upthesystemandconnecttotheinteractiveREPLand
4.5.3ModemFirmwareUpdate
243
runthefollowingcode:
importsqnsupgrade
sqnsupgrade.run(path_to_firmware,921600)#path_to_firmwareexample:'/sd/FIPY_NB1_
35351.dup'
Thewholeprocesscantakebetween2and3minutesandatsomepointsitwillseemto
stall,thisisnormal,justbepatience.Youshouldseeanoutputlikethis:
<<<WelcometotheSQN3330firmwareupdater>>>
Enteringrecoverymode
Resetting.
StartingSTP(DONOTDISCONNECTPOWER!!!)
STPstarted
Sessionopened:version1,maxtransfer8192bytes
Sending4560505bytes:[########################################]100%
Codedownloaddone,returningtousermode
Resetting(DONOTDISCONNECTPOWER!!!).
.........
Deployingtheupgrade(DONOTDISCONNECTPOWER!!!)...
Resetting(DONOTDISCONNECTPOWER!!!)..
...
Upgradecompleted!
Hereisthecurrentfirmwareversion:
UE6.0.0.0-ER7
LR6.0.0.0-35351
OK
DONOTdisconnectpowerwhiletheupgradeprocessistakingplace,waitforittofinish!
Ifthemoduleget'sstuckinhereformorethan1minutewhileupgradingtotheNB-IoT
firmware,youcancyclepowerandretry.Inthiscaseitissafe.
Sending4560505bytes:[##]6%
4.5.3ModemFirmwareUpdate
244
Accelerometer
BoththePysenseandPytrackusethesameaccelerometer.PleaseseethePysense
Examplestoseehowtousetheaccelerometer.
4.6PytrackExamples
245
SensorDemos
Accelerometer
Thisbasicexampleshowshowtoreadpitchandrollfromtheon-boardaccelerometerand
outputitincommaseparatedvalue(CSV)formatoverserial.
fromLIS2HH12importLIS2HH12
frompytrackimportPytrack
py=Pytrack()
acc=LIS2HH12()
whileTrue:
pitch=acc.pitch()
roll=acc.roll()
print('{},{}'.format(pitch,roll))
time.sleep_ms(100)
IfyouwanttovisualisethedataoutputbythisscriptaProcessingsketchisavailablehere
thatwillshowtheboardorientationin3D.
4.7PysenseExamples
246
4.7PysenseExamples
247
Introduction
Thischapterdescribesmodules(functionandclasslibraries)thatarebuiltintoMicroPython.
Thereareanumberofcategoriesfortheavailablemodules:
ModuleswhichimplementasubsetofstandardPythonfunctionalityandarenot
intendedtobeextendedbytheuser.
ModuleswhichimplementasubsetofPythonfunctionality,withaprovisionfor
extensionbytheuser(viaPythoncode).
ModuleswhichimplementMicroPythonextensionstothePythonstandardlibraries.
Modulesspecifictoaparticularportandthusnotportable.
Noteabouttheavailabilityofmodulesandtheircontents
Thisdocumentationingeneralaspirestodescribeallmodulesandfunctions/classeswhich
areimplementedinMicroPython.However,MicroPythonishighlyconfigurable,andeach
porttoaparticularboard/embeddedsystemmakesavailableonlyasubsetofMicroPython
libraries.Forofficiallysupportedports,thereisanefforttoeitherfilteroutnon-applicable
items,ormarkindividualdescriptionswith“Availability:”clausesdescribingwhichports
provideagivenfeature.Withthatinmind,pleasestillbewarnedthatsomefunctions/classes
inamodule(oreventheentiremodule)describedinthisdocumentationmaybeunavailable
inaparticularbuildofMicroPythononaparticularboard.Thebestplacetofindgeneral
informationoftheavailability/non-availabilityofaparticularfeatureisthe“General
Information”sectionwhichcontainsinformationpertainingtoaspecificport.
Beyondthebuilt-inlibrariesdescribedinthisdocumentation,manymoremodulesfromthe
Pythonstandardlibrary,aswellasfurtherMicroPythonextensionstoit,canbefoundinthe
micropython-librepository.
5.1Introduction
248
PycomModules
ThesemodulesarespecifictothePycomdevicesandmayhaveslightlydifferent
implementationstoothervariationsofMicroPython(i.e.forNon-Pycomdevices).Modules
includethosewhichsupportaccesstounderlyinghardware,e.g.I2C,SPI,WLAN,Bluetooth,
etc.
5.2PycomModules
249
modulemachine
The machinemodulecontainsspecificfunctionsrelatedtotheboard.
QuickUsageExample
importmachine
help(machine)#displayallmembersfromthemachinemodule
machine.freq()#gettheCPUfrequency
machine.unique_id()#returnthe6-byteuniqueidoftheboard(theLoPy'sWiFiMACad
dress)
ResetFunctions
machine.reset()
ResetsthedeviceinamannersimilartopushingtheexternalRESETbutton.
machine.reset_cause()
Gettheresetcause.Seeconstantsforthepossiblereturnvalues.
InterruptFunctions
machine.disable_irq()
Disableinterruptrequests.ReturnsandintegerrepresentingthepreviousIRQstate.This
returnvaluecanbepassedto enable_irqtorestoretheIRQtoitsoriginalstate.
machine.enable_irq([state])
Enableinterruptrequests.Themostcommonuseofthisfunctionistopassthevalue
returnedby disable_irqtoexitacriticalsection.Anotheroptionsistoenableallinterrupts
whichcanbeachievedbycallingthefunctionwithnoparameters.
PowerFunctions
machine.freq()
ReturnsCPUfrequencyinhertz.
5.2.1machine
250
machine.idle()
GatestheclocktotheCPU,usefultoreducepowerconsumptionatanytimeduringshortor
longperiods.Peripheralscontinueworkingandexecutionresumesassoonasanyinterrupt
istriggered(onmanyportsthisincludessystemtimerinterruptoccurringatregularintervals
ontheorderofmillisecond).
machine.deepsleep([time_ms])
StopstheCPUandallperipherals,includingthenetworkinginterfaces(exceptforLTE).
Executionisresumedfromthemainscript,justaswithareset.Ifavalueinmillisecondsis
giventhenthedevicewillwakeupafterthatperiodoftime,otherwiseitwillremainindeep
sleepuntiltheresetbuttonispressed.
TheproductswithLTEconnectivity(FiPy,GPy,G01),requiretheLTEradiotobedisabled
separatelyviatheLTEclassbeforeenteringdeepsleep.ThisisrequiredduetotheLTE
radiobeingpoweredindependentlyandallowingusecaseswhichrequirethesystemtobe
takenoutfromdeepsleepbyaneventfromtheLTEnetwork(dataorSMSreceivedfor
instance).
machine.pin_deepsleep_wakeup(pins,mode,enable_pull)
Configurepinstowakeupfromdeepsleepmode.Thepinswhichhavethiscapabilityare:
P2,P3,P4,P6,P8toP10andP13toP23.
Theargumentsare:
pinsalistortuplecontainingthe GPIOtosetupfordeepsleepwakeup.
modeselectsthewaytheconfigure GPIOscanwakeupthemodule.Thepossible
valuesare: machine.WAKEUP_ALL_LOWand machine.WAKEUP_ANY_HIGH.
enable_pullifsetto Truekeepsthepulluporpulldownresistorsenabledduring
deepsleep.Ifthisvariableissetto True,then ULPorcapacitivetouchwakeupcannot
beusedincombinationwith GPIOwakeup.
machine.wake_reason()
Getthewakereason.Seeconstantsforthepossiblereturnvalues.Returnsatupleofthe
form: (wake_reason,gpio_list).WhenthewakeupreasoniseitherGPIOortouchpad,
thenthesecondelementofthetupleisalistwithGPIOsthatgeneratedthewakeup.
machine.remaining_sleep_time()
Returnstheremainingtimerduration(inmilliseconds)iftheESP32iswokenupfromdeep
sleepbysomethingotherthanthetimer.Forexample,ifyousetthetimerfor30seconds
(30000ms)anditwakesupafter10secondsthenthisfunctionwillreturn 20000.
5.2.1machine
251
MiscellaneousFunctions
machine.main(filename)
Setthe filenameofthemainscripttorunafter boot.pyisfinished.Ifthisfunctionisnot
calledthenthedefaultfile main.pywillbeexecuted.
Itonlymakessensetocallthisfunctionfromwithin boot.py.
machine.rng()
Returna24-bitsoftwaregeneratedrandomnumber.
machine.unique_id()
Returnsabytestringwithauniqueidentifierofaboard/SoC.Itwillvaryfromaboard/SoC
instancetoanother,ifunderlyinghardwareallows.Lengthvariesbyhardware(souse
substringofafullvalueifyouexpectashortID).InsomeMicroPythonports,IDcorresponds
tothenetworkMACaddress.
Use ubinascii.hexlify()toconvertthebytestringtohexadecimalformforeaseof
manipulationanduseelsewhere.
machine.info()
Returnsthehighwatermarkofthestackassociatedwithvarioussystemtasks,inwords(1
word=4bytesontheESP32).Ifthevalueiszerothenthetaskhaslikelyoverflowedits
stack.Ifthevalueisclosetozerothenthetaskhascomeclosetooverflowingitsstack.
Constants
ResetCauses
machine.PWRON_RESETmachine.HARD_RESETmachine.WDT_RESET
machine.DEEPSLEEP_RESETmachine.SOFT_RESETmachine.BROWN_OUT_RESET
WakeReasons
machine.PWRON_WAKEmachine.PIN_WAKEmachine.RTC_WAKEmachine.ULP_WAKE
PinWakeupModes
5.2.1machine
252
machine.WAKEUP_ALL_LOWmachine.WAKEUP_ANY_HIGH
5.2.1machine
253
classADC–AnalogtoDigitalConversion
QuickUsageExample
importmachine
adc=machine.ADC()#createanADCobject
apin=adc.channel(pin='P16')#createananalogpinonP16
val=apin()#readananalogvalue
Constructors
classmachine.ADC(id=0)
CreateanADCobject;associateachannelwithapin.Formoreinfocheckthehardware
section.
Methods
adc.init(*,bits=12)
EnabletheADCblock.Thismethodisautomaticallycalledonobjectcreation.
Bitscantakevaluesbetween9and12andselectsthenumberofbitsofresolutionof
theADCblock.
adc.deinit()
DisabletheADCblock.
adc.channel(*,pin,attn=ADC.ATTN_0DB)
Createananalogpin.
pinisakeyword-onlystringargument.Validpinsare P13to P20.
attnistheattenuationlevel.Thesupportedvaluesare:ADC.ATTN_0DB
ADC.ATTN_2_5DBADC.ATTN_6DBADC.ATTN_11DB
ReturnsaninstanceofADCChannel.Example:
#enableanADCchannelonP16
apin=adc.channel(pin='P16')
5.2.1.1ADC
254
adc.vref(vref)
Ifcalledwithoutanyarguments,thisfunctionreturnsthecurrentcalibratedvoltage(in
millivolts)ofthe 1.1vreference.Otherwiseitwillupdatethecalibratedvalue(inmillivolts)
oftheinternal 1.1vreference.
adc.vref_to_pin(pin)
Connectstheinternal 1.1vtoexternal GPIO.Itcanonlybeconnectedto P22, P21or
P6.Itisrecommendedtoonlyuse P6ontheWiPy,onothermodulesthispinis
connectedtotheradio.
Constants
ADC.ATTN_0DBADC.ATTN_2_5DBADC.ATTN_6DBADC.ATTN_11DB
ADCchannelattenuationvalues
classADCChannel
Readanalogvaluesfrominternal/externalsources.ADCchannelscanbeconnectedto
internalpointsofthe MCUorto GPIOpins.ADCchannelsarecreatedusingthe
ADC.channelmethod.
Methods
adcchannel()
Fastmethodtoreadthechannelvalue.
adcchannel.value()
Readthechannelvalue.
adcchannel.init()
(Re)initandenabletheADCchannel.Thismethodisautomaticallycalledonobjectcreation.
adcchannel.deinit()
DisabletheADCchannel.
adcchannel.voltage()
Readsthechannelsvalueandconvertsitintoavoltage(inmillivolts)
5.2.1.1ADC
255
adcchannel.value_to_voltage(value)
Convertstheprovidedvalueintoavoltage(inmillivolts)inthesamewayvoltagedoes.
ADCpininputrangeis 0-1.1V.Thismaximumvaluecanbeincreasedupto 3.3V
usingthehighestattenuationof 11dB.Donotexceedthemaximumof3.3V,toavoid
damagingthedevice.
5.2.1.1ADC
256
classDAC–DigitaltoAnalogConversion
TheDACisusedtooutputanalogvalues(aspecificvoltage)onpin P22orpin P21.The
voltagewillbebetween 0and 3.3V.
QuickUsageExample
importmachine
dac=machine.DAC('P22')#createaDACobject
dac.write(0.5)#setoutputto50%
dac_tone=machine.DAC('P21')#createaDACobject
dac_tone.tone(1000,0)#settoneoutputto1kHz
Constructors
classclassmachine.DAC(pin)
CreateaDACobject,thatwillletyouassociateachannelwitha pin. pincanbeastring
argument.
Methods
dac.init()
EnabletheDACblock.Thismethodisautomaticallycalledonobjectcreation.
dac.deinit()
DisabletheDACblock.
dac.write(value)
SettheDClevelforaDACpin. valueisafloatargument,withvaluesbetween0and1.
dac.tone(frequency,amplitude)
Setsuptonesignaltothespecified frequencyat amplitudescale. frequencycanbefrom
125Hzto 20kHzinstepsof 122Hz. amplitudeisanintegerspecifyingthetoneamplitude
towritetheDACpin.Amplitudevaluerepresents:
5.2.1.2DAC
257
0is0dBV(~3Vppat600Ohmload)
1is-6dBV(~1.5Vpp), 2is-12dBV(~0.8Vpp)
3is-18dBV(~0.4Vpp).ThegeneratedsignalisasinewavewithanDCoffsetof
VDD/2.
5.2.1.2DAC
258
classI2C–Two-WireSerialProtocol
I2Cisatwo-wireprotocolforcommunicatingbetweendevices.Atthephysicallevelit
consistsof2wires:SCLandSDA,theclockanddatalinesrespectively.
I2Cobjectsarecreatedattachedtoaspecificbus.Theycanbeinitialisedwhencreated,or
initialisedlateron.
ExampleusingdefaultPins
frommachineimportI2C
i2c=I2C(0)#createonbus0
i2c=I2C(0,I2C.MASTER)#createandinitasamaster
i2c=I2C(0,pins=('P10','P11'))#createandusenon-defaultPINassignments(P10
=SDA,P11=SCL)
i2c.init(I2C.MASTER,baudrate=20000)#initasamaster
i2c.deinit()#turnofftheperipheral
Exampleusingnon-defaultPins
frommachineimportI2C
i2c=I2C(0,pins=('P10','P11'))#createandusenon-defaultPINassignments(P10
=SDA,P11=SCL)
i2c.init(I2C.MASTER,baudrate=20000)#initasamaster
i2c.deinit()#turnofftheperipheral
Printingthe i2cobjectgivesyouinformationaboutitsconfiguration.
Amastermustspecifytherecipient’saddress:
i2c.init(I2C.MASTER)
i2c.writeto(0x42,'123')#send3bytestoslavewithaddress0x42
i2c.writeto(addr=0x42,b'456')#keywordforaddress
Masteralsohasothermethods:
5.2.1.3I2C
259
i2c.scan()#scanforslavesonthebus,returning
#alistofvalidaddresses
i2c.readfrom_mem(0x42,2,3)#read3bytesfrommemoryofslave0x42,
#startingataddress2intheslave
i2c.writeto_mem(0x42,2,'abc')#write'abc'(3bytes)tomemoryofslave0x42
#startingataddress2intheslave,timeoutafte
r1second
QuickUsageExample
frommachineimportI2C
#configuretheI2Cbus
i2c=I2C(0,I2C.MASTER,baudrate=100000)
i2c.scan()#returnslistofslaveaddresses
i2c.writeto(0x42,'hello')#send5bytestoslavewithaddress0x42
i2c.readfrom(0x42,5)#receive5bytesfromslave
i2c.readfrom_mem(0x42,0x10,2)#read2bytesfromslave0x42,slavememory0x10
i2c.writeto_mem(0x42,0x10,'xy')#write2bytestoslave0x42,slavememory0x10
Constructors
classmachine.I2C(bus,...)
ConstructanI2Cobjectonthegiven bus. buscanonlybe 0,1,2.Ifthe busisnot
given,thedefaultonewillbeselected( 0).Buses 0and 1usetheESP32I2Chardware
peripheralwhilebus 2isimplementedwithabit-bangedsoftwaredriver.
GeneralMethods
i2c.init(mode,*,baudrate=100000,pins=(SDA,SCL))
InitialisetheI2Cbuswiththegivenparameters:
modemustbeI2C.MASTER
baudrateistheSCLclockrate
pinsisanoptionaltuplewiththepinstoassigntotheI2Cbus.ThedefaultI2Cpinsare
P9(SDA)and P10(SCL)
i2c.scan()
ScanallI2Caddressesbetween 0x08and 0x77inclusiveandreturnalistofthosethat
respond.AdevicerespondsifitpullstheSDAlinelowafteritsaddress(includingareadbit)
issentonthebus.
5.2.1.3I2C
260
StandardBusOperations
ThefollowingmethodsimplementthestandardI2Cmasterreadandwriteoperationsthat
targetagivenslavedevice.
i2c.readfrom(addr,nbytes)
Read nbytesfromtheslavespecifiedby addr.Returnsabytesobjectwiththedataread.
i2c.readfrom_into(addr,buf)
Readinto buffromtheslavespecifiedby addr.Thenumberofbytesreadwillbethe
lengthof buf.
Returnvalueisthenumberofbytesread.
i2c.writeto(addr,buf,*,stop=True)
Writethebytesfrom buftotheslavespecifiedby addr.Theargument bufcanalsobe
anintegerwhichwillbetreatedasasinglebyte.If stopissetto Falsethenthestop
conditionwon’tbesentandtheI2Coperationmaybecontinued(typicallywitharead
transaction).
Returnvalueisthenumberofbyteswritten.
MemoryOperations
SomeI2Cdevicesactasamemorydevice(orsetofregisters)thatcanbereadfromand
writtento.InthiscasetherearetwoaddressesassociatedwithanI2Ctransaction:theslave
addressandthememoryaddress.Thefollowingmethodsareconveniencefunctionsto
communicatewithsuchdevices.
i2c.readfrom_mem(addr,memaddr,nbytes,*,addrsize=8)
Read nbytesfromtheslavespecifiedby addrstartingfromthememoryaddressspecified
by memaddr.The addrsizeargumentisspecifiedinbitsanditcanonlytake8or16.
i2c.readfrom_mem_into(addr,memaddr,buf,*,addrsize=8)
Readinto buffromtheslavespecifiedby addrstartingfromthememoryaddress
specifiedby memaddr.Thenumberofbytesreadisthelengthof buf.The addrsize
argumentisspecifiedinbitsanditcanonlytake8or16.
Thereturnvalueisthenumberofbytesread.
i2c.writeto_mem(addr,memaddr,buf*,addrsize=8)
5.2.1.3I2C
261
Write buftotheslavespecifiedby addrstartingfromthememoryaddressspecifiedby
memaddr.Theargument bufcanalsobeanintegerwhichwillbetreatedasasinglebyte.
The addrsizeargumentisspecifiedinbitsanditcanonlytake8or16.
Thereturnvalueisthenumberofbyteswritten.
Constants
I2C.MASTER
Usedtoinitialisethebustomastermode.
5.2.1.3I2C
262
classPin–ControlI/OPins
ApinisthebasicobjecttocontrolI/Opins(alsoknownasGPIO-general-purpose
input/output).Ithasmethodstosetthemodeofthepin(input,output,etc)andmethodsto
getandsetthedigitallogiclevel.Foranalogcontrolofapin,seetheADCclass.
QuickUsageExample
frommachineimportPin
#initialize`P9`ingpiomodeandmakeitanoutput
p_out=Pin('P9',mode=Pin.OUT)
p_out.value(1)
p_out.value(0)
p_out.toggle()
p_out(True)
#make`P10`aninputwiththepull-upenabled
p_in=Pin('P10',mode=Pin.IN,pull=Pin.PULL_UP)
p_in()#getvalue,0or1
Constructors
classmachine.Pin(id,...)
CreateanewPinobjectassociatedwiththestring id.Ifadditionalargumentsaregiven,
theyareusedtoinitialisethepin.Seepin.init().
frommachineimportPin
p=Pin('P10',mode=Pin.OUT,pull=None,alt=-1)
Methods
pin.init(mode,pull,*,alt)
Initialisethepin:
modecanbeoneof:
Pin.IN-inputpin.
Pin.OUT-outputpininpush-pullmode.
Pin.OPEN_DRAIN-inputoroutputpininopen-drainmode.
5.2.1.4Pin
263
pullcanbeoneof:
None-nopullupordownresistor.
Pin.PULL_UP-pullupresistorenabled.
Pin.PULL_DOWN-pulldownresistorenabled.
altistheidofthealternatefunction.
Returns: None.
pin.id()
Getthepinid.
pin.value([value])
Getorsetthedigitallogiclevelofthepin:
Withnoargument,return0or1dependingonthelogiclevelofthepin.
Withvaluegiven,setthelogiclevelofthepin.valuecanbeanythingthatconvertstoa
boolean.IfitconvertstoTrue,thepinissethigh,otherwiseitissetlow.
pin([value])
Pinobjectsarecallable.Thecallmethodprovidesa(fast)shortcuttosetandgetthevalue
ofthepin.
Example:
frommachineimportPin
pin=Pin('P12',mode=Pin.IN,pull=Pin.PULL_UP)
pin()#fastmethodtogetthevalue
Seepin.value()formoredetails.
pin.toggle()
Togglethevalueofthepin.
pin.mode([mode])
Getorsetthepinmode.
pin.pull([pull])
Getorsetthepinpull.
pin.hold([hold])
5.2.1.4Pin
264
Getorsetthepinhold.Youcanapplyaholdtoapinbypassing True(orclearitby
passing False).Whenapinisheld,itsvaluecannotbechangedbyusing Pin.value()or
Pin.toggle()untiltheholdisreleased.ThisCanbeusedtoretainthepinstatethrougha
coreresetandsystemresettriggeredbywatchdogtime-outorDeep-sleepevents.Onlypins
intheRTCpowerdomaincanretaintheirvaluethroughdeepsleeporreset.Theseare: P2,
P3,P4,P6,P8,P9,P10,P13,P14,P15,P16,P17,P18,P19,P20,P21,P22,P23.
pin.callback(trigger,handler=None,arg=None)
Setacallbacktobetriggeredwhentheinputlevelatthepinchanges.
triggeristhetypeofeventthattriggersthecallback.Possiblevaluesare:
Pin.IRQ_FALLINGinterruptonfallingedge.
Pin.IRQ_RISINGinterruptonrisingedge.
Pin.IRQ_LOW_LEVELinterruptonlowlevel.
Pin.IRQ_HIGH_LEVELinterruptonhighlevel.
ThevaluescanbeOR-edtogether,forinstance trigger=Pin.IRQ_FALLING|Pin.IRQ_RISING
handleristhefunctiontobecalledwhentheeventhappens.Thisfunctionwillreceive
oneargument.Set handlerto Nonetodisableit.
argisanoptionalargumenttopasstothecallback.Ifleftemptyorsetto None,the
functionwillreceivethePinobjectthattriggeredit.
Example:
frommachineimportPin
defpin_handler(arg):
print("gotaninterruptinpin%s"%(arg.id()))
p_in=Pin('P10',mode=Pin.IN,pull=Pin.PULL_UP)
p_in.callback(Pin.IRQ_FALLING|Pin.IRQ_RISING,pin_handler)
FormoreinformationonhowPycom’sproductshandleinterrupts,seehere.
Attributes
classpin.exp_board
ContainsallPinobjectssupportedbytheexpansionboard.Examples:
5.2.1.4Pin
265
Pin.exp_board.G16
led=Pin(Pin.exp_board.G16,mode=Pin.OUT)
Pin.exp_board.G16.id()
classpin.module
Containsall Pinobjectssupportedbythemodule.Examples:
Pin.module.P9
led=Pin(Pin.module.P9,mode=Pin.OUT)
Pin.module.P9.id()
Constants
Thefollowingconstantsareusedtoconfigurethepinobjects.Notethatnotallconstantsare
availableonallports.
Pin.INPin.OUTPin.OPEN_DRAIN
Selectsthepinmode.
Pin.PULL_UPPin.PULL_DOWN
Enablesthepulluporpulldownresistor.
5.2.1.4Pin
266
classPWM–PulseWidthModulation
QuickUsageExample
frommachineimportPWM
pwm=PWM(0,frequency=5000)#usePWMtimer0,withafrequencyof5KHz
#createpwmchannelonpinP12withadutycycleof50%
pwm_c=pwm.channel(0,pin='P12',duty_cycle=0.5)
pwm_c.duty_cycle(0.3)#changethedutycycleto30%
Constructors
classmachine.PWM(timer,frequency)
CreateaPWMobject.Thissetsupthe timertooscillateatthespecified frequency.
timerisanintegerfrom0to3. frequencyisanintegerfrom1Hzto78KHz(thisvalues
canchangeinfutureupgrades).
Methods
pwm.channel(id,pin*,duty_cycle=0.5)
ConnectaPWMchanneltoapin,settingtheinitialdutycycle. idisanintegerfrom0to7.
pinisastringargument. duty_cycleisakeyword-onlyfloatargument,withvalues
between0and1.Returnsaninstanceof PWMChannel.
classPWMChannel—PWMchannel
Methods
pwmchannel.duty_cycle(value)
SetthedutycycleforaPWMchannel. valueisafloatargument,withvaluesbetween0
and1.
5.2.1.5PWM
267
classRTC–RealTimeClock
TheRTCisusedtokeeptrackofthedateandtime.
QuickUsageExample
frommachineimportRTC
rtc=RTC()
rtc.init((2014,5,1,4,13,0,0,0))
print(rtc.now())
Constructors
classmachine.RTC(id=0,...)
CreateanRTCobject.Seeinitforparametersofinitialisation.
#idoftheRTCmaybesetifmultipleareconnected.Defaultstoid=0.
rtc=RTC(id=0)
Methods
rtc.init(datetime=None,source=RTC.INTERNAL_RC)
InitialisetheRTC.Theargumentsare:
datetimewhenpasseditsetsthecurrenttime.Itisatupleoftheform: (year,month,
day[,hour[,minute[,second[,microsecond[,tzinfo]]]]]).
sourceselectstheoscillatorthatdrivestheRTC.TheoptionsareRTC.INTERNAL_RC
andRTC.XTAL_32KHZ
Forexample:
#for2ndofFebruary2017at10:30am(TZ0)
rtc.init((2017,2,28,10,30,0,0,0))
tzinfoisignoredbythismethod.Use time.timezonetoachievesimilarresults.
5.2.1.6RTC
268
rtc.now()
Getgetthecurrent datetimetuple:
#returnsdatetimetuple
rtc.now()
rtc.ntp_sync(server,*,update_period=3600)
SetupautomaticfetchandupdatethetimeusingNTP(SNTP).
serveristheURLoftheNTPserver.Canbesetto Nonetodisabletheperiodic
updates.
update_periodisthenumberofsecondsbetweenupdates.Shortestperiodis15
seconds.
Canbeusedlike:
rtc.ntp_sync("pool.ntp.org")#thisisanexample.Youcanselectamorespecificserv
eraccordingtoyourgeographicallocation
rtc.synced()
Returns Trueifthelast ntp_synchasbeencompleted, Falseotherwise:
rtc.synced()
Constants
RTC.INTERNAL_RCRTC.XTAL_32KHZ
Clocksource
5.2.1.6RTC
269
classSPI–SerialPeripheralInterface
SPIisaserialprotocolthatisdrivenbyamaster.Atthephysicallevelthereare3lines:
SCK,MOSI,MISO.
SeeusagemodelofI2C;SPIisverysimilar.MaindifferenceisparameterstoinittheSPI
bus:
frommachineimportSPI
spi=SPI(0,mode=SPI.MASTER,baudrate=1000000,polarity=0,phase=0,firstbit=SPI.MSB)
Onlyrequiredparameterismode,mustbeSPI.MASTER.Polaritycanbe0or1,andisthe
leveltheidleclocklinesitsat.Phasecanbe0or1tosampledataonthefirstorsecond
clockedgerespectively.
QuickUsageExample
frommachineimportSPI
#configuretheSPImaster@2MHz
#thisusestheSPIdefaultpinsforCLK,MOSIandMISO(``P10``,``P11``and``P14``)
spi=SPI(0,mode=SPI.MASTER,baudrate=2000000,polarity=0,phase=0)
spi.write(bytes([0x01,0x02,0x03,0x04,0x05]))#send5bytesonthebus
spi.read(5)#receive5bytesonthebus
rbuf=bytearray(5)
spi.write_readinto(bytes([0x01,0x02,0x03,0x04,0x05]),rbuf)#sendareceive5byt
es
QuickUsageExampleusingnon-defaultpins
5.2.1.7SPI
270
frommachineimportSPI
#configuretheSPImaster@2MHz
#thisusestheSPInon-defaultpinsforCLK,MOSIandMISO(``P19``,``P20``and``P2
1``)
spi=SPI(0,mode=SPI.MASTER,baudrate=2000000,polarity=0,phase=0,pins=('P19','P20',
'P21'))
spi.write(bytes([0x01,0x02,0x03,0x04,0x05]))#send5bytesonthebus
spi.read(5)#receive5bytesonthebus
rbuf=bytearray(5)
spi.write_readinto(bytes([0x01,0x02,0x03,0x04,0x05]),rbuf)#sendareceive5byt
es
Constructors
classmachine.SPI(id,...)
ConstructanSPIobjectonthegivenbus. idcanbeonly0.Withnoadditionalparameters,
theSPIobjectiscreatedbutnotinitialised(ithasthesettingsfromthelastinitialisationofthe
bus,ifany).Ifextraargumentsaregiven,thebusisinitialised.Seeinitforparametersof
initialisation.
Methods
spi.init(mode,baudrate=1000000,*,polarity=0,phase=0,bits=8,firstbit=SPI.MSB,
pins=(CLK,MOSI,MISO))
InitialisetheSPIbuswiththegivenparameters:
modemustbeSPI.MASTER.
baudrateistheSCKclockrate.
polaritycanbe0or1,andistheleveltheidleclocklinesitsat.
phasecanbe0or1tosampledataonthefirstorsecondclockedgerespectively.
bitsisthewidthofeachtransfer,acceptedvaluesare8,16and32.
firstbitcanbeSPI.MSBorSPI.LSB.
pinsisanoptionaltuplewiththepinstoassigntotheSPIbus.Ifthepinsargumentis
notgiventhedefaultpinswillbeselected( P10asCLK, P11asMOSIand P14as
MISO).IfpinsispassedasNonethennopinassignmentwillbemade.
spi.deinit()
TurnofftheSPIbus.
spi.write(buf)
5.2.1.7SPI
271
Writethedatacontainedin buf.Returnsthenumberofbyteswritten.
spi.read(nbytes,*,write=0x00)
Readthe nbyteswhilewritingthedataspecifiedby write.Returnthenumberofbytes
read.
spi.readinto(buf,*,write=0x00)
Readintothebufferspecifiedby bufwhilewritingthedataspecifiedby write.Returnthe
numberofbytesread.
spi.write_readinto(write_buf,read_buf)
Writefrom write_bufandreadinto read_buf.Bothbuffersmusthavethesamelength.
Returnsthenumberofbyteswritten
Constants
SPI.MASTER
ForinitialisingtheSPIbustomaster
SPI.MSB
Setthefirstbittobethemostsignificantbit
SPI.LSB
Setthefirstbittobetheleastsignificantbit
5.2.1.7SPI
272
classUART–UniversalAsynchronous
Receiver/Transmitter
UARTimplementsthestandardUART/USARTduplexserialcommunicationsprotocol.Atthe
physicallevelitconsistsof2lines:RXDandTXD.Theunitofcommunicationisacharacter
(nottobeconfusedwithastringcharacter)whichcanbe5,6,7or8bitswide.
UARTobjectscanbecreatedandinitialisedusing:
frommachineimportUART
uart=UART(1,9600)#initwithgivenbaudrate
uart.init(9600,bits=8,parity=None,stop=1)#initwithgivenparameters
Bitscanbe 5,6,7,8.Paritycanbe None,UART.EVENorUART.ODD.Stopcanbe 1,
1.5or2.
AUARTobjectactslikeastreamobjectthereforereadingandwritingisdoneusingthe
standardstreammethods:
uart.read(10)#read10characters,returnsabytesobject
uart.readall()#readallavailablecharacters
uart.readline()#readaline
uart.readinto(buf)#readandstoreintothegivenbuffer
uart.write('abc')#writethe3characters
Tocheckifthereisanythingtoberead,use:
uart.any()#returnsthenumberofcharactersavailableforreading
QuickUsageExample
frommachineimportUART
#thisusestheUART_1defaultpinsforTXDandRXD(``P3``and``P4``)
uart=UART(1,baudrate=9600)
uart.write('hello')
uart.read(5)#readupto5bytes
QuickUsageExampleusingnon-defaultpins(TXD/RXD
only)
5.2.1.8UART
273
frommachineimportUART
#thisusestheUART_1non-defaultpinsforTXDandRXD(``P20``and``P21``)
uart=UART(1,baudrate=9600,pins=('P20','P21'))
uart.write('hello')
uart.read(5)#readupto5bytes
QuickUsageExampleusingnon-defaultpins(TXD/RXD
andflowcontrol)
frommachineimportUART
#thisusestheUART_1non-defaultpinsforTXD,RXD,RTSandCTS(``P20``,``P21``,`
`P22``and``P23``)
uart=UART(1,baudrate=9600,pins=('P20','P21','P22','P23'))
uart.write('hello')
uart.read(5)#readupto5bytes
Constructors
classmachine.UART(bus,...)
ConstructaUARTobjectonthegiven bus. buscanbe 0,1or2.Ifthe busisnot
given,thedefaultonewillbeselected( 0)ortheselectionwillbemadebasedonthegiven
pins.
OntheGPy/FiPyUART2isunavailablebecauseitisusedtocommunicatewiththe
cellularradio.
Methods
uart.init(baudrate=9600,bits=8,parity=None,stop=1,*,timeout_chars=2,pins=(TXD,
RXD,RTS,CTS))
InitialisetheUARTbuswiththegivenparameters:
baudrateistheclockrate.
bitsisthenumberofbitspercharacter.Canbe 5,6,7or8.
parityistheparity, None,UART.EVENorUART.ODD.
stopisthenumberofstopbits, 1or2.
timeout_charsRxtimeoutdefinedinnumberofcharacters.Thevaluegivenherewill
bemultipliedbythetimeacharacterstakestobetransmittedattheconfigured
baudrate.
5.2.1.8UART
274
pinsisa4or2itemlistindicatingtheTXD,RXD,RTSandCTSpins(inthatorder).
Anyofthepinscanbe NoneifonewantstheUARTtooperatewithlimitedfunctionality.
IftheRTSpinisgiventhetheRXpinmustbegivenaswell.ThesameappliestoCTS.
Whennopinsaregiven,thenthedefaultsetofTXD(P1)andRXD(P0)pinsistaken,
andhardwareflowcontrolwillbedisabled.If pins=None,nopinassignmentwillbe
made.
uart.deinit()
TurnofftheUARTbus.
uart.any()
Returnthenumberofcharactersavailableforreading.
uart.read([nbytes])
Readcharacters.If nbytesisspecifiedthenreadatmostthatmanybytes.
Returnvalue:abytesobjectcontainingthebytesreadin.Returns Noneontimeout.
uart.readall()
Readasmuchdataaspossible.
Returnvalue:abytesobjector Noneontimeout.
uart.readinto(buf[,nbytes])
Readbytesintothe buf.If nbytesisspecifiedthenreadatmostthatmanybytes.
Otherwise,readatmost len(buf)bytes.
Returnvalue:numberofbytesreadandstoredinto bufor Noneontimeout.
uart.readline()
Readaline,endinginanewlinecharacter.Ifsuchalineexists,returnisimmediate.Ifthe
timeoutelapses,allavailabledataisreturnedregardlessofwhetheranewlineexists.
Returnvalue:thelinereador Noneontimeoutifnodataisavailable.
uart.write(buf)
Writethebufferofbytestothebus.
Returnvalue:numberofbyteswrittenorNoneontimeout.
uart.sendbreak()
5.2.1.8UART
275
Sendabreakconditiononthebus.Thisdrivesthebuslowforadurationof13bits.Return
value: None.
uart.wait_tx_done(timeout_ms)
Waitsatmost timeout_msforthelastTxtransactiontocomplete.Returns Trueifalldata
hasbeensentandtheTXbufferhasnodatainit,otherwisereturns False.
Constants
UART.EVENUART.ODD
Paritytypes(alongwith None)
UART.RX_ANY
IRQtriggersources
5.2.1.8UART
276
classWDT–WatchdogTimer
TheWDTisusedtorestartthesystemwhentheapplicationcrashesandendsupintoanon
recoverablestate.Afterenabling,theapplicationmust"feed"thewatchdogperiodicallyto
preventitfromexpiringandresettingthesystem.
QuickUsageExample
frommachineimportWDT
wdt=WDT(timeout=2000)#enableitwithatimeoutof2seconds
wdt.feed()
Constructors
classmachine.WDT(id=0,timeout)
CreateaWDTobjectandstartit.The idcanonlybe 0.Seetheinitmethodforthe
parametersofinitialisation.
Methods
wdt.init(timeout)
Initialisesthewatchdogtimer.Thetimeoutmustbegiveninmilliseconds.Onceitisrunning
theWDTcannotbestoppedbutthetimeoutcanbere-configuredatanypointintime.
wdt.feed()
FeedtheWDTtopreventitfromresettingthesystem.Theapplicationshouldplacethiscall
inasensibleplaceensuringthattheWDTisonlyfedafterverifyingthateverythingis
functioningcorrectly.
5.2.1.9WDT
277
classTimer–MeasureTimeandSet
Alarms
Timerscanbeusedforagreatvarietyoftasks,likemeasuringtimespansorbeingnotified
thataspecificintervalhaselapsed.
Thesetwoconceptsaregroupedintotwodifferentsubclasses:
Chrono:usedtomeasuretimespans. Alarm:togetinterruptedafteraspecificinterval.
Youcancreateasmanyoftheseobjectsasneeded.
Constructors
classTimer.Chrono()
Createachronometerobject.
classTimer.Alarm(handler=None,s,*,ms,us,arg=None,periodic=False)
CreateanAlarmobject.
handler:willbecalledaftertheintervalhaselapsed.Ifsetto None,thealarmwillbe
disabledaftercreation.
arg:anoptionalargumentcanbepassedtothecallbackhandlerfunction.If Noneis
specified,thefunctionwillreceivetheobjectthattriggeredthealarm.
s,ms,us:theintervalcanbespecifiedinseconds(float),miliseconds(integer)or
microseconds(integer).Onlyoneatatimecanbespecified.
periodic:analarmcanbesettotriggerrepeatedlybysettingthisparameterto True.
Methods
Timer.sleep_us()
Delayforagivennumberofmicroseconds,shouldbepositiveor0(forspeed,thecondition
isnotenforced).Internallyitusesthesametimerastheotherelementsofthe Timerclass.
Itcompensatesforthecallingoverhead,soforexample,100usshouldbereallycloseto
100us.Fortimesbiggerthan10,000usitreleasestheGILtoletotherthreadsrun,so
exactitudeisnotguaranteedfordelayslongerthanthat.
5.2.1.10Timer
278
classChrono
Canbeusedtomeasuretimespans.
Methods
chrono.start()
Startthechronometer.
chrono.stop()
Stopthechronometer.
chrono.reset()
Resetthetimecountto0.
chrono.read()
Gettheelapsedtimeinseconds.
chrono.read_ms()
Gettheelapsedtimeinmilliseconds.
chrono.read_us()
Gettheelapsedtimeinmicroseconds.
Example:
5.2.1.10Timer
279
frommachineimportTimer
importtime
chrono=Timer.Chrono()
chrono.start()
time.sleep(1.25)#simulatethefirstlaptook1.25seconds
lap=chrono.read()#readelapsedtimewithoutstopping
time.sleep(1.5)
chrono.stop()
total=chrono.read()
print()
print("\ntheracertook%fsecondstofinishtherace"%total)
print("%fsecondsinthefirstlap"%lap)
print("%fsecondsinthelastlap"%(total-lap))
classAlarm–getinterruptedafteraspecificinterval
Methods
alarm.callback(handler,*,arg=None)
Specifyacallbackhandlerforthealarm.Ifsetto None,thealarmwillbedisabled.
Anoptionalargument argcanbepassedtothecallbackhandlerfunction.If Noneis
specified,thefunctionwillreceivetheobjectthattriggeredthealarm.
alarm.cancel()
Disablesthealarm.
Example:
frommachineimportTimer
classClock:
def__init__(self):
self.seconds=0
self.__alarm=Timer.Alarm(self._seconds_handler,1,periodic=True)
def_seconds_handler(self,alarm):
self.seconds+=1
print("%02dsecondshavepassed"%self.seconds)
ifself.seconds==10:
alarm.cancel()#stopcountingafter10seconds
clock=Clock()
5.2.1.10Timer
280
FormoreinformationonhowPycom’sproductshandleinterrupts,seenotes.
5.2.1.10Timer
281
classSD–SecuredigitalMemoryCard
TheSDcardclassallowstoconfigureandenablethememorycardmoduleofyourPycom
moduleandautomaticallymountitas /sdaspartofthefilesystem.Thereisasinglepin
combinationthatcanbeusedfortheSDcard,andthecurrentimplementationonlyworksin
1-bitmode.Thepinconnectionsareasfollows:
P8:DAT0, P23:SCLKand P4:CMD(noexternalpull-upresistorsareneeded)
IfyouhaveoneofthePycomexpansionboards,thensimplyinsertthecardintothemicro
SDsocketandrunyourscript.
MakesureyourSDcardisformattedeitherasFAT16orFAT32.
QuickExampleUsage:
frommachineimportSD
importos
sd=SD()
os.mount(sd,'/sd')
#checkthecontent
os.listdir('/sd')
#trysomestandardfileoperations
f=open('/sd/test.txt','w')
f.write('TestingSDcardwriteoperations')
f.close()
f=open('/sd/test.txt','r')
f.readall()
f.close()
Constructors
classmachine.SD(id,...)
CreateaSDcardobject.Seesd.init()forparametersifinitialisation.
Methods
5.2.1.11SD
282
sd.init(id=0)
EnabletheSDcard.
sd.deinit()
DisabletheSDcard.
PleasenotethattheSDcardlibrarycurrentlysupportsFAT16/32formattedSDcardsup
to32GB.Futurefirmwareupdateswillincreasecompatibilitywithadditionalformatsand
sizes.
5.2.1.11SD
283
classCAN–ControllerAreaNetwork
TheCANclasssupportsthefullCAN2.0specificationwithstandardandextendedframes,
aswellasacceptancefiltering.
TheESP32hasabuilt-inCANcontroller,butthetransceiverneedstobeaddedexternally.A
recommendeddeviceistheSN65HVD230.
QuickUsageExample
frommachineimportCAN
can=CAN(mode=CAN.NORMAL,baudrate=500000,pins=('P22','P23'))
can.send(id=12,data=bytes([1,2,3,4,5,6,7,8]))
can.recv()
Constructors
classmachine.CAN(bus=0,...)
CreateanCANobject.Seeinitforparametersofinitialisation.:
#only1CANperipheralisavailable,sothebusmustalwaysbe0
can=CAN(0,mode=CAN.NORMAL,baudrate=500000,pins=('P22','P23'))#pinorderis
Tx,Rx
Methods
can.init(mode=CAN.NORMAL,baudrate=500000,*,frame_format=CAN.FORMAT_STD,
rx_queue_len=128,pins=('P22','P23'))
InitializetheCANcontroller.Theargumentsare:
modecantakeeitherCAN.NORMALorCAN.SILENT.Silentmodeisusefulforsniffing
thebus.
baudratesetsupthebusspeed.Acceptablevaluesarebetween1and1000000.
frame_formatdefinestheframeformattobeacceptedbythereceiver.Usefulfor
filteringframesbasedontheidentifierlength.CantaleeitherCAN.FORMAT_STDor
CAN.FORMAT_EXTorCAN.FORMAT_BOTH.IfCAN.FORMAT_STDisselected,
extendedframeswon'tbereceivedandvice-versa.
5.2.1.12CAN
284
rx_queue_lendefinesthenumberofmessagesthancanbequeuedbythereceiver.
DuetoCANbeingahightrafficbus,largevaluesarerecommended(>=128),otherwise
messageswillbedroppedspeciallywhennofilteringisapplied.
pinsselectsthe Txand Rxpins(inthatorder).
can.deinit()
DisablestheCANbus.
#disabletheCANbus
can.deinit()
can.send(id,*,data=None,rtr=False,extended=False)
SendaCANframeonthebus
idistheidentifierofthemessage.
datacantakeupto8bytes.Itmustbeleftemptyisthemessagetobesentisa
remoterequest(rtr=True).
rtrsetittofalsetosendaremoterequest.
extntedspecifiesifthemessageidentifierwidthshouldbe11bit(standard)or29bit
(extended).
Canbeusedlike:
can.send(id=0x0020,data=bytes([0x01,0x02,0x03,0x04,0x05]),extended=True)#sen
ds5byteswithanextendedidentifier
can.send(id=0x010,data=bytes([0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08]))#sen
ds8byteswithanstandardidentifier
can.send(id=0x012,rtr=True)#sendsaremoterequestformessageid=0x12
can.recv(timeout=0)
Getamessagefromthereceivequeue,andoptionallyspecifyatimeoutvalueins(canbea
floatingpointvaluee.g. 0.2).Thisfunctionreturns Noneifnomessagesavailable.Ifa
messageispresent,itwillbereturnedasanamedtuplewiththefollowingform:
(id,data,rtr,extended)
>>>can.recv()
(id=0x012,data=b'123',rtr=False,extended=False)
can.soft_filter(mode,filter_list)
5.2.1.12CAN
285
Specifyasoftwarefilteracceptingonlythemessagesthatpassthefiltertest.
Thereare3possiblefiltermodes:
CAN.FILTER_LISTallowstopassthelistofIDsthatshouldbeaccepted.
CAN.FILTER_RANGEallowstopassalistortupleofIDrangesthatshouldbe
accepted.
CAN.FILTER_MASKallowstopassalistoftuplesoftheform: (filer,mask).
WithsoftwarefiltersallmessagesinthebusarereceivedbytheCANcontrollerbutonlythe
matchingonesarepassedtotheRXqueue.Thismeansthatthequeuewon'tbefilledup
withnonrelevantmessages,buttheinterruptoverheadwillremainasnormal.The
filter_listcancontainupto32elements.
Forexample:
can.soft_filter(CAN.FILTER_LIST,[0x100,0x200,0x300,0x400])#onlyacceptidentifi
ersfrom0x100,0x200,0x300and0x400
can.soft_filter(CAN.FILTER_RANGE,[(0x001,0x010),(0x020,0x030),(0x040,0x050)])#
onlyacceptidentifiersfrom0x001to0x010,from0x020to0x030andfrom0x040to0x
050.
can.soft_filter(CAN.FILTER_MASK,[(0x100,0x7FF),(0x200,0x7FC)])#moreoftheclass
icFilterandMaskmethod.
can.soft_filter(None)#disablesoftfilters,allmessagesareaccepted
can.callback(trigger,handler=None,arg=None)
Setacallbacktobetriggeredwhenanyofthis3eventsarepresent:
triggeristhetypeofeventthattriggersthecallback.Possiblevaluesare:
CAN.RX_FRAMEinterruptwheneveranewframeisreceived.
CAN.RX_FIFO_NOT_EMPTYinterruptwhenaframeisreceivedonanempty
FIFO.
CAN.RX_FIFO_OVERRUNinterruptwhenamessageisreceivedandtheFIFOis
full.
ThevaluescanbeOR-edtogether,forinstancetrigger=CAN.RX_FRAME|
CAN.RX_FIFO_OVERRUN
handleristhefunctiontobecalledwhentheeventhappens.Thisfunctionwillreceive
oneargument.SethandlertoNonetodisablethecallback.
argisanoptionalargumenttopasstothecallback.IfleftemptyorsettoNone,the
functionwillreceivetheCANobjectthattriggeredit.
5.2.1.12CAN
286
Itcanbeusedlikethis:
frommachineimportCAN
can=CAN(mode=CAN.NORMAL,baudrate=500000,pins=('P22','P23'))
defcan_cb(can_o):
print('CANRx:',can_o.recv())
can.callback(handler=can_cb,trigger=CAN.RX_FRAME)
can.events()
Thismethodreturnsavaluewithbitssets(ifany)indicatingtheeventsthathaveoccurredin
thebus.Pleasenotethatbycallingthisfunctiontheinternaleventsregistryiscleared
automatically,thereforecallingitimmediatelyforasecondtimewillmostlikelyreturnavalue
of0.
Constants
CAN.NORMALCAN.SILENTCAN.FORMAT_STDCAN.FORMAT_EXT
CAN.FORMAT_BOTHCAN.RX_FRAMECAN.RX_FIFO_NOT_EMPTY
CAN.RX_FIFO_OVERRUNCAN.FILTER_LISTCAN.FILTER_RANGECAN.FILTER_MASK
5.2.1.12CAN
287
classRMT–RemoteController
TheRMT(RemoteControl)moduleisprimarilydesignedtosendandreceiveinfrared
remotecontrolsignalsthatuseon-off-keyingofacarrierfrequency,butduetoitsdesignit
canbeusedtogeneratevarioustypesofsignals.
QuickUsageExample:sending
importmachine
#createaRMTobjectfortransmission
rmt=machine.RMT(channel=3,gpio="P20",tx_idle_level=0)
#createseriesofbitstosend
data=(1,0,1,0,1,0,1,0,1)
#definedurationofthebits,timeunitdependsontheselectedRMTchannel
duration=10000
#sendthesignal
rmt.send_pulses(duration,data)
QuickUsageExample:receiving
importmachine
#createaRMTobject
rmt=machine.RMT(channel=3)
#ConfigureRTMforreceiving
rmt.init(gpio="P20",rx_idle_threshold=12000)
#waitforanynumberofpulsesuntilonelongerthanrx_idle_threshold
data=rmt.recv_pulses()
Constructors
classmachine.RMT(channel,...)
ConstructanRMTobjectonthegivenchannel. channelcanbe2-7.Withnoadditional
parameters,theRMTobjectiscreatedbutnotinitialised.Ifextraargumentsaregiven,the
RMTisinitialisedfortransmissionorreception.See initforparametersofinitialisation.
Theresolutionwhichapulsecanbesent/receiveddependsontheselectedchannel:
5.2.1.13RMT
288
Channel Resolution MaximumPulseWidth
0 Usedbyon-boardLED
1 Usedby pycom.pulses_get()
2 100nS 3.2768ms
3 100nS 3.2768ms
4 1000nS 32.768ms
5 1000nS 32.768ms
6 3125nS 102.4ms
7 3125nS 102.4ms
Methods
rmt.init(gpio,rx_idle_threshold,rx_filter_threshold,tx_idle_level,tx_carrier)
InitialisetheRMTperipheralwiththegivenparameters:
gpioistheGPIOPintouse.
rx_idle_thresholdisthemaximumdurationofavalidpulse.Therepresentedtimeunit
(resolution)dependsontheselectedchannel,valuecanbe0-65535.
rx_filter_thresholdistheminimumdurationofavalidpulse.Therepresentedtime
unit(resolution)dependsontheselectedchannel,valuecanbe0-31.
tx_idle_levelistheoutputsignal'slevelafterthetransmissionisfinished,canbe
RMT.HIGHorRMT.LOW.
tx_carrieristhemodulationofthepulsestosend.
Either rx_idle_thresholdor tx_idle_levelmustbedefined,bothcannotbegivenatthe
sametimebecauseachannelcanbeconfiguredinRXorTXmodeonly.
rx_filter_thresholdisnotmandatoryparameter.Ifnotgiventhenallpulsesareaccepted
withdurationlessthan rx_idle_threshold. tx_carrierisnotmandatoryparameters.Ifnot
givennomodulationisusedonthesentpulses.
The tx_carrierparameterisatuplewiththefollowingstructure:
carrier_freq_hzisthecarrier'sfrequencyinHz.
carrier_duty_percentisthedutypercentofthecarrier'ssignal,canbe0%-100%.
carrier_levelisthelevelofthepulsetomodulate,canbeRMT.HIGHorRMT.LOW.
rmt.deinit()
DeinitialisetheRMTobject.
5.2.1.13RMT
289
IfanRMTobjectneedstobereconfiguredfromRX/TXtoTX/RX,theneitherfirst
deinit()mustbecalledorthe init()againwiththedesiredconfiguration.
rmt.pulses_get(pulses,timeout)
ReadsinpulsesfromtheGPIOpin.
pulsesifnotspecified,thisfunctionwillkeepreadingpulsesuntilthe
rx_idle_thresholdisexceeded.Ifitisspecifiedthisfunctionwillreturntheexactlythat
numberofpulses,ignoringanythingshorterthan rx_filter_thresholdorlongerthan
rx_idle_threshold.
timeoutisspecified,thisfunctionwillreturnifthefirstpulsedoesnotoccurwithin
timeoutmicroseconds.Ifnotspecified,itwillwaitindefinitely.
Returnvalue:Tupleofitemswiththefollowingstructure:(level,duration):
levelrepresentsthelevelofthereceivedbit/pulse,canbe0or1.
durationrepresentsthedurationofthereceivedpulse,thetimeunit(resolution)
dependsontheselectedchannel.
Maximumof128pulsescanbereceivedinarowwithoutreceiving"idle"signal.Ifthe
incomingpulsesequencecontainsmorethan128pulsestherestisdroppedandthe
receiverwaitsforanothersequenceofpulses.The pulses_getfunctioncanbecalled
toreceivemorethan128pulses,howevertheabovementionedlimitationshouldbe
keptinmindwhenevaluatingthereceiveddata.
rmt.pulses_send(duration,data,start_level)
Generatespulsesasdefinedbytheparametersbelow
durationrepresentsthedurationofthepulsestobesent,thetimeunit(resolution)
dependsontheselectedchannel.
dataTuplethatrepresentsthesequenceofpulsestobesent,mustbecomposedof0
or1elements.
start_leveldefinesthestate(HIGH/LOW)ofthefirstpulsegivenby durationif
dataisnotgiven.
datamustbeatupleand durationcanbeatupleorasinglenumber,with databeing
optional.Inthecasethatonly durationisprovided,itmustbeatupleandyoumustalso
provide start_levelwhichwilldictatethelevelofthefirstduration,thesignallevelthen
togglesbetweeneachdurationvalue.If dataisprovidedand durationisasinglenumber,
5.2.1.13RMT
290
eachpulsein datawillhavehaveanequallengthassetby duration.If dataand
durationareprovidedastuples,theymustbeofthesamenumberofelements,witheach
pulselastingitsmatchingduration.
Constants
RMT.LOWRMT.HIGH
Definesthelevelofthepulse.
5.2.1.13RMT
291
modulenetwork
Thismoduleprovidesaccesstonetworkdriversandroutingconfiguration.Networkdrivers
forspecifichardwareareavailablewithinthismoduleandareusedtoconfigurespecific
hardwarenetworkinterfaces.
5.2.2network
292
classWLAN
ThisclassprovidesadriverfortheWiFinetworkprocessorinthemodule.Exampleusage:
importnetwork
importtime
#setupasastation
wlan=network.WLAN(mode=network.WLAN.STA)
wlan.connect('your-ssid',auth=(network.WLAN.WPA2,'your-key'))
whilenotwlan.isconnected():
time.sleep_ms(50)
print(wlan.ifconfig())
#nowusesocketasusual
QuickUsageExample
importmachine
fromnetworkimportWLAN
#configuretheWLANsubsysteminstationmode(thedefaultisAP)
wlan=WLAN(mode=WLAN.STA)
#goforfixedIPsettings(IP,Subnet,Gateway,DNS)
wlan.ifconfig(config=('192.168.0.107','255.255.255.0','192.168.0.1','192.168.0.1'))
wlan.scan()#scanforavailablenetworks
wlan.connect(ssid='mynetwork',auth=(WLAN.WPA2,'my_network_key'))
whilenotwlan.isconnected():
pass
print(wlan.ifconfig())
Constructors
classnetwork.WLAN(id=0,...)
CreateaWLANobject,andoptionallyconfigureit.Seeinitforparamsofconfiguration.
TheWLANconstructorisspecialinthesensethatifnoargumentsbesidesthe idare
given,itwillreturnthealreadyexistingWLANinstancewithoutre-configuringit.Thisis
becauseWLANisasystemfeatureoftheWiPy.Ifthealreadyexistinginstanceisnot
initialiseditwilldothesameastheotherconstructorsanwillinitialiseitwithdefault
values.
5.2.2.1WLAN
293
Methods
wlan.init(mode,*,ssid=None,auth=None,channel=1,antenna=None,
power_save=False,hidden=False)
SetorgettheWiFinetworkprocessorconfiguration.
Argumentsare:
modecanbeeitherWLAN.STA,WLAN.APorWLAN.STA_AP.
ssidisastringwiththeSSIDname.OnlyneededwhenmodeisWLAN.AP.
authisatuplewith(sec,key).Securitycanbe None,WLAN.WEP,WLAN.WPAor
WLAN.WPA2.Thekeyisastringwiththenetworkpassword.If secisWLAN.WEPthe
keymustbeastringrepresentinghexadecimalvalues(e.g. ABC1DE45BF).Onlyneeded
whenmodeisWLAN.AP.
channelanumberintherange1-11.OnlyneededwhenmodeisWLAN.AP.
antennaselectsbetweentheinternalandtheexternalantenna.Canbeeither
WLAN.INT_ANT,WLAN.EXT_ANT.Withourdevelopmentboardsitdefaultstousing
theinternalantenna,butinthecaseofanOEMmodule,theantennapin( P12)isnot
used,soit’sfreetobeusedforotherthings.
power_saveenablesordisablespowersavefunctionsinSTAmode.
hiddenonlyvalidinWLAN.APmodetocreateanaccesspointwithahiddenSSID
whensetto True.
Forexample,youcando:
#createandconfigureasanaccesspoint
wlan.init(mode=WLAN.AP,ssid='wipy-wlan',auth=(WLAN.WPA2,'www.wipy.io'),channel=7,a
ntenna=WLAN.INT_ANT)
or:
#configureasanstation
wlan.init(mode=WLAN.STA)
wlan.deinit()
DisablestheWiFiradio.
wlan.connect(ssid,*,auth=None,bssid=None,timeout=None,ca_certs=None,
keyfile=None,certfile=None,identity=None)
ConnecttoawifiaccesspointusingthegivenSSID,andothersecurityparameters.
5.2.2.1WLAN
294
authisatuplewith (sec,key).Securitycanbe None,WLAN.WEP,WLAN.WPA,
WLAN.WPA2orWLAN.WPA2_ENT.Thekeyisastringwiththenetworkpassword.If
secisWLAN.WEPthekeymustbeastringrepresentinghexadecimalvalues(e.g.
ABC1DE45BF).If secisWLAN.WPA2_ENTthenthe authtuplecanhaveeither3
elements: (sec,username,password),orjust1: (sec,).Whenpassingthe3element
tuple,the keyfileand certifleargumentsmustnotbegiven.
bssidistheMACaddressoftheAPtoconnectto.UsefulwhenthereareseveralAPs
withthesameSSID.
timeoutisthemaximumtimeinmillisecondstowaitfortheconnectiontosucceed.
ca_certsisthepathtotheCAcertificate.Thisargumentisnotmandatory. keyfileis
thepathtotheclientkey.Onlyusedif usernameand passwordarenotpartofthe
authtuple.
certfileisthepathtotheclientcertificate.Onlyusedif usernameand passwordare
notpartofthe authtuple.
identityisonlyusedincaseofWLAN.WPA2_ENTsecurity.
wlan.scan()
Performsanetworkscanandreturnsalistofnamedtupleswith(ssid,bssid,sec,
channel,rssi).Notethatchannelisalways Nonesincethisinfoisnotprovidedbythe
WiPy.
wlan.disconnect()
DisconnectfromtheWiFiaccesspoint.
wlan.isconnected()
IncaseofSTAmode,returns TrueifconnectedtoaWiFiaccesspointandhasavalidIP
address.InAPmodereturns Truewhenastationisconnected, Falseotherwise.
wlan.ifconfig(id=0,config=['dhcp'orconfigtuple])
When idis0,theconfigurationwillbeget/setontheStationinterface.When idis1the
configurationwillbedonefortheAPinterface.
Withnoparametersgivenreturnsa4-tupleof (ip,subnet_mask,gateway,DNS_server).
If dhcpispassedasaparameterthentheDHCPclientisenabledandtheIPparamsare
negotiatedwiththeAP.
Ifthe4-tupleconfigisgiventhenastaticIPisconfigured.Forinstance:
wlan.ifconfig(config=('192.168.0.4','255.255.255.0','192.168.0.1','8.8.8.8'))
5.2.2.1WLAN
295
wlan.mode([mode])
GetorsettheWLANmode.
wlan.ssid([ssid])
GetorsettheSSIDwheninAPmode.
wlan.auth([auth])
GetorsettheauthenticationtypewheninAPmode.
wlan.channel([channel])
Getorsetthechannel(onlyapplicableinAPmode).
wlan.antenna([antenna])
Getorsettheantennatype(externalorinternal).
wlan.mac()
Geta6-bytelong bytesobjectwiththeWiFIMACaddress.
Constants
WLAN.STAWLAN.APWLAN.STA_AP
WLANmode
WLAN.WEPWLAN.WPAWLAN.WPA2WLAN.WPA2_ENT
WLANnetworksecurity
WLAN.INT_ANTWLAN.EXT_ANT
Antennatype
5.2.2.1WLAN
296
classServer
The ServerclasscontrolsthebehaviourandtheconfigurationoftheFTPandtelnet
servicesrunningonthePycomdevice.Anychangesperformedusingthisclass’methods
willaffectboth.
Example:
importnetwork
server=network.Server()
server.deinit()#disabletheserver
#enabletheserveragainwithnewsettings
server.init(login=('user','password'),timeout=600)
QuickUsageExample
fromnetworkimportServer
#initwithnewuser,passwordandsecondstimeout
server=Server(login=('user','password'),timeout=60)
server.timeout(300)#changethetimeout
server.timeout()#getthetimeout
server.isrunning()#checkwhethertheserverisrunningornot
Constructors
classnetwork.Server(id,...)
Createaserverinstance,see initforparametersofinitialisation.
Methods
server.init(*,login=('micro','python'),timeout=300)
Init(andeffectivelystarttheserver).Optionallyanew user, passwordand timeout(in
seconds)canbepassed.
server.deinit()
Stoptheserver.
server.timeout([timeout_in_seconds])
5.2.2.2Server
297
Getorsettheservertimeout.
server.isrunning()
Returns Trueiftheserverisrunning(connectedoracceptingconnections), False
otherwise.
5.2.2.2Server
298
classBluetooth
ThisclassprovidesadriverfortheBluetoothradiointhemodule.Currently,onlybasicBLE
functionalityisavailable.
QuickUsageExample
fromnetworkimportBluetooth
importtime
bt=Bluetooth()
bt.start_scan(-1)
whileTrue:
adv=bt.get_adv()
ifadvandbt.resolve_adv_data(adv.data,Bluetooth.ADV_NAME_CMPL)=='HeartRate':
try:
conn=bt.connect(adv.mac)
services=conn.services()
forserviceinservices:
time.sleep(0.050)
iftype(service.uuid())==bytes:
print('Readingcharsfromservice={}'.format(service.uuid()))
else:
print('Readingcharsfromservice=%x'%service.uuid())
chars=service.characteristics()
forcharinchars:
if(char.properties()&Bluetooth.PROP_READ):
print('char{}value={}'.format(char.uuid(),char.read()))
conn.disconnect()
break
except:
print("ErrorwhileconnectingorreadingfromtheBLEdevice")
break
else:
time.sleep(0.050)
BluetoothLowEnergy(BLE)
Bluetoothlowenergy(BLE)isasubsetofclassicBluetooth,designedforeasyconnecting
andcommunicatingbetweendevices(inparticularmobileplatforms).BLEusesa
methodologyknownasGenericAccessProfile(GAP)tocontrolconnectionsand
advertising.
5.2.2.3Bluetooth
299
GAPallowsfordevicestotakevariousrolesbutgenericflowworkswithdevicesthatare
eitheraServer(lowpower,resourceconstrained,sendingsmallpayloadsofdata)oraClient
device(commonlyamobiledevice,PCorPycomDevicewithlargeresourcesand
processingpower).PycomdevicescanactasbothaClientandaServer.
Constructors
classnetwork.Bluetooth(id=0,...)
CreateaBluetoothobject,andoptionallyconfigureit.Seeinitforparamsofconfiguration.
Example:
fromnetworkimportBluetooth
bluetooth=Bluetooth()
Methods
bluetooth.init(id=0,mode=Bluetooth.BLE,antenna=None)
idOnlyoneBluetoothperipheralavailablesomustalwaysbe0
modecurrentlytheonlysupportedmodeis Bluetooth.BLE
antennaselectsbetweentheinternalandtheexternalantenna.Canbeeither
Bluetooth.INT_ANT,Bluetooth.EXT_ANT.Withourdevelopmentboardsitdefaultsto
usingtheinternalantenna,butinthecaseofanOEMmodule,theantennapin( P12)is
notused,soit’sfreetobeusedforotherthings.
InitialisesandenablestheBluetoothradioinBLEmode.
bluetooth.deinit()
DisablestheBluetoothradio.
bluetooth.start_scan(timeout)
StartsperformingascanlisteningforBLEdevicessendingadvertisements.Thisfunction
alwaysreturnsimmediately,thescanningwillbeperformedonthebackground.Thereturn
valueis None.Afterstartingthescanthefunctionget_adv()canbeusedtoretrievethe
advertisementsmessagesfromtheFIFO.TheinternalFIFOhasspacetocache16
advertisements.
Theargumentsare:
timeoutspecifiestheamountoftimeinsecondstoscanforadvertisements,cannotbe
5.2.2.3Bluetooth
300
zero.Iftimeoutis>0,thentheBLEradiowilllistenforadvertisementsuntilthespecified
valueinsecondselapses.Iftimeout<0,thenthere’snotimeoutatall,andstop_scan()
needstobecalledtocancelthescanningprocess.
Examples:
bluetooth.start_scan(10)#startsscanningandstopafter10seconds
bluetooth.start_scan(-1)#startsscanningindefinitelyuntilbluetooth.stop_sc
an()iscalled
bluetooth.stop_scan()
Stopsanongoingscanningprocess.Returns None.
bluetooth.isscanning()
Returns TrueifaBluetoothscanisinprogress. Falseotherwise.
bluetooth.get_adv()
Getsannamedtuplewiththeadvertisementdatareceivedduringthescanning.Thetuple
hasthefollowingstructure: (mac,addr_type,adv_type,rssi,data)
macisthe6-bytelingmacaddressofthedevicethatsenttheadvertisement.
addr_typeistheaddresstype.Seetheconstantssectionbelowformoredetails.
adv_typeistheadvertisementtypereceived.Seetheconstantssectionbelowfromore
details.
rssiissignedintegerwiththesignalstrengthoftheadvertisement.
datacontainsthecomplete31bytesoftheadvertisementmessage.Inordertoparse
thedataandgetthespecifictypes,themethodresolve_adv_data()canbeused.
Exampleforgetting macaddressofanadvertiser:
importubinascii
bluetooth=Bluetooth()
bluetooth.start_scan(20)#scanfor20seconds
adv=bluetooth.get_adv()#
ubinascii.hexlify(adv.mac)#converthexadecimaltoascii
bluetooth.get_advertisements()
Sameasthe get_adv()method,butthisonereturnsalistwithalltheadvertisements
received.
5.2.2.3Bluetooth
301
bluetooth.resolve_adv_data(data,data_type)
Parsestheadvertisementdataandreturnstherequested data_typeifpresent.Ifthedata
typeisnotpresent,thefunctionreturns None.
Arguments:
dataisthebytesobjectwiththecompleteadvertisementdata.
data_typeisthedatatypetoresolvefromfromtheadvertisementdata.Seeconstants
sectionbelowfordetails.
Example:
importubinascii
fromnetworkimportBluetooth
bluetooth=Bluetooth()
bluetooth.start_scan(20)
whilebluetooth.isscanning():
adv=bluetooth.get_adv()
ifadv:
#trytogetthecompletename
print(bluetooth.resolve_adv_data(adv.data,Bluetooth.ADV_NAME_CMPL))
mfg_data=bluetooth.resolve_adv_data(adv.data,Bluetooth.ADV_MANUFACTURER_DAT
A)
ifmfg_data:
#trytogetthemanufacturerdata(Apple'siBeacondataissenthere)
print(ubinascii.hexlify(mfg_data))
bluetooth.connect(mac_addr)
OpensaBLEconnectionwiththedevicespecifiedbythe mac_addrargument.Thisfunction
blocksuntiltheconnectionsucceedsorfails.Iftheconnectionssucceedsitreturnsaobject
oftype GATTCConnection.
bluetooth.connect('112233eeddff')#macaddressisacceptedasastring
bluetooth.callback(trigger=None,handler=None,arg=None)
Createsacallbackthatwillbeexecutedwhenanyofthetriggersoccurs.Thearguments
are:
triggercanbeeitherBluetooth.NEW_ADV_EVENT,
Bluetooth.CLIENT_CONNECTEDorBluetooth.CLIENT_DISCONNECTED
handleristhefunctionthatwillbeexecutedwhenthecallbackistriggered.
5.2.2.3Bluetooth
302
argistheargumentthatgetspassedtothecallback.Ifnothingisgiventhebluetooth
objectitselfisused.
Anexampleofhowthismaybeusedcanbeseeninthebluetooth.events()method.
bluetooth.events()
Returnsavaluewithbitflagsidentifyingtheeventsthathaveoccurredsincethelastcall.
Callingthisfunctionclearstheevents.
Exampleofusage:
fromnetworkimportBluetooth
bluetooth=Bluetooth()
bluetooth.set_advertisement(name='LoPy',service_uuid=b'1234567890123456')
defconn_cb(bt_o):
events=bt_o.events()#thismethodreturnstheflagsandclearstheinternalr
egistry
ifevents&Bluetooth.CLIENT_CONNECTED:
print("Clientconnected")
elifevents&Bluetooth.CLIENT_DISCONNECTED:
print("Clientdisconnected")
bluetooth.callback(trigger=Bluetooth.CLIENT_CONNECTED|Bluetooth.CLIENT_DISCONNECTED,
handler=conn_cb)
bluetooth.advertise(True)
bluetooth.set_advertisement(*,name=None,manufacturer_data=None,
service_data=None,service_uuid=None)
Configurethedatatobesentwhileadvertising.Ifleftwiththedefaultof Nonethedatawon’t
bepartoftheadvertisementmessage.
Theargumentsare:
nameisthestringnametobeshownonadvertisements.
manufacturer_datamanufacturerdatatobeadvertised(hint:useitforiBeacons).
service_dataservicedatatobeadvertised.
service_uuiduuidoftheservicetobeadvertised.
Example:
bluetooth.set_advertisement(name="advert",manufacturer_data="lopy_v1")
5.2.2.3Bluetooth
303
bluetooth.advertise([Enable])
Startorstopsendingadvertisements.Theset_advertisement()methodmusthavebeen
calledpriortothisone.
bluetooth.service(uuid,*,isprimary=True,nbr_chars=1,start=True)
CreateanewserviceontheinternalGATTserver.Returnsaobjectoftype
BluetoothServerService.
Theargumentsare:
uuidistheUUIDoftheservice.Cantakeanintegerora16bytelongstringorbytes
object.
isprimaryselectsiftheserviceisaprimaryone.Takesa boolvalue.
nbr_charsspecifiesthenumberofcharacteristicsthattheservicewillcontain.
startif Truetheserviceisstartedimmediately.
bluetooth.service('abc123')
bluetooth.disconnect_client()
ClosestheBLEconnectionwiththeclient.
Constants
Bluetoothmode
Bluetooth.BLE
Advertisementtype
Bluetooth.CONN_ADVBluetooth.CONN_DIR_ADVBluetooth.DISC_ADV
Bluetooth.NON_CONN_ADVBluetooth.SCAN_RSP
Addresstype
Bluetooth.PUBLIC_ADDRBluetooth.RANDOM_ADDRBluetooth.PUBLIC_RPA_ADDR
Bluetooth.RANDOM_RPA_ADDR
Advertisementdatatype
Bluetooth.ADV_FLAGBluetooth.ADV_16SRV_PARTBluetooth.ADV_T16SRV_CMPL
Bluetooth.ADV_32SRV_PARTBluetooth.ADV_32SRV_CMPL
Bluetooth.ADV_128SRV_PARTBluetooth.ADV_128SRV_CMPL
5.2.2.3Bluetooth
304
Bluetooth.ADV_NAME_SHORTBluetooth.ADV_NAME_CMPLBluetooth.ADV_TX_PWR
Bluetooth.ADV_DEV_CLASSBluetooth.ADV_SERVICE_DATA
Bluetooth.ADV_APPEARANCEBluetooth.ADV_ADV_INT
Bluetooth.ADV_32SERVICE_DATABluetooth.ADV_128SERVICE_DATA
Bluetooth.ADV_MANUFACTURER_DATA
Characteristicproperties(bitvaluesthatcanbecombined)
Bluetooth.PROP_BROADCASTBluetooth.PROP_READBluetooth.PROP_WRITE_NR
Bluetooth.PROP_WRITEBluetooth.PROP_NOTIFYBluetooth.PROP_INDICATE
Bluetooth.PROP_AUTHBluetooth.PROP_EXT_PROP
Characteristiccallbackevents
Bluetooth.CHAR_READ_EVENTBluetooth.CHAR_WRITE_EVENT
Bluetooth.NEW_ADV_EVENTBluetooth.CLIENT_CONNECTED
Bluetooth.CLIENT_DISCONNECTEDBluetooth.CHAR_NOTIFY_EVENT
Antennatype
Bluetooth.INT_ANTBluetooth.EXT_ANT
5.2.2.3Bluetooth
305
GenericAttribute
GATTstandsfortheGenericAttributeProfileanditdefinesthewaythattwoBluetoothLow
EnergydevicescommunicatebetweeneachotherusingconceptscalledServicesand
Characteristics.GATTusesadataprotocolknownastheAttributeProtocol(ATT),whichis
usedtostore/manageServices,Characteristicsandrelateddatainalookuptable.
GATTcomesintouseonceaconnectionisestablishedbetweentwodevices,meaningthat
thedevicewillhavealreadygonethroughtheadvertisingprocessmanagedbyGAP.It’s
importanttorememberthatthisconnectionisexclusive;i.e.thatonlyoneclientisconnected
tooneserveratatime.Thismeansthattheclientwillstopadvertisingonceaconnection
hasbeenmade.Thisremainsthecase,untiltheconnectionisbrokenordisconnected.
TheGATTServer,whichholdstheATTlookupdataandserviceandcharacteristic
definitions,andtheGATTClient(thephone/tablet),whichsendsrequeststothisserver.
5.2.2.3Bluetooth
306
classGATTCConnection
TheGATTClientisthedevicethatrequestsdatafromtheserver,otherwiseknownasthe
masterdevice(commonlythismightbeaphone/tablet/PC).Alltransactionsareinitiatedby
themaster,whichreceivesaresponsefromtheslave.
connection.disconnect()
ClosestheBLEconnection.Returns None.
connection.isconnected()
Returns Trueiftheconnectionisstillopen. Falseotherwise.
Example:
fromnetworkimportBluetooth
importubinascii
bluetooth=Bluetooth()
#scanuntilwecanconnecttoanyBLEdevicearound
bluetooth.start_scan(-1)
adv=None
whileTrue:
adv=bluetooth.get_adv()
ifadv:
try:
bluetooth.connect(adv.mac)
except:
#startscanningagain
bluetooth.start_scan(-1)
continue
break
print("Connectedtodevicewithaddr={}".format(ubinascii.hexlify(adv.mac)))
connection.services()
PerformsaservicesearchontheconnectedBLEperipheral(server)areturnsalist
containingobjectsoftheclassGATTCServiceifthesearchsucceeds.
Example:
5.2.2.3Bluetooth
307
#assumingthataBLEconnectionisalreadyopen
services=connection.services()
print(services)
forserviceinservices:
print(service.uuid())
5.2.2.3Bluetooth
308
classGATTCService
Servicesareusedtocategorisedataupintospecificchunksofdataknownas
characteristics.Aservicemayhavemultiplecharacteristics,andeachservicehasaunique
numericIDcalledaUUID.
ThefollowingclassallowscontroloverClientservices.
service.isprimary()
Returns Trueiftheserviceisaprimaryone. Falseotherwise.
service.uuid()
ReturnstheUUIDoftheservice.Inthecaseof16-bitor32-bitlongUUIDs,thevalue
returnedisaninteger,butfor128-bitlongUUIDsthevaluereturnedisabytesobject.
service.instance()
ReturnstheinstanceIDoftheservice.
service.characteristics()
PerformsagetcharacteristicsrequestontheconnectedBLEperipheralareturnsalist
containingobjectsoftheclassGATTCCharacteristiciftherequestsucceeds.
5.2.2.3Bluetooth
309
classGATTCCharacteristic
ThesmallestconceptinGATTistheCharacteristic,whichencapsulatesasingledatapoint
(thoughitmaycontainanarrayofrelateddata,suchasX/Y/Zvaluesfroma3-axis
accelerometer,longitudeandlatitudefromaGPS,etc.).
ThefollowingclassallowsyoutomanagecharacteristicsfromaClient.
characteristic.uuid()
ReturnstheUUIDoftheservice.Inthecaseof16-bitor32-bitlongUUIDs,thevalue
returnedisaninteger,butfor128-bitlongUUIDsthevaluereturnedisabytesobject.
characteristic.instance()
ReturnstheinstanceIDoftheservice.
characteristic.properties()
Returnsanintegerindicatingthepropertiesofthecharacteristic.Propertiesarerepresented
bybitvaluesthatcanbeOR-edtogether.Seetheconstantssectionformoredetails.
characteristic.read()
Readthevalueofthecharacteristic,sendingarequesttotheGATTserver.Returnsabytes
objectrepresentingthecharacteristicvalue.
characteristic.value()
Returnsthelocallystoredvalueofthecharacteristicwithoutsendingareadrequesttothe
GATTserver.Ifthecharacteristicvaluehasn'tbeenreadfromtheGATTserveryet,thevalue
returnedwillbe0.
characteristic.write(value)
Writesthegivenvalueonthecharacteristic.Fornowitonlyacceptsbytesobject
representingthevaluetobewritten.
characteristic.write(b'x0f')
characteristic.callback(trigger=None,handler=None,arg=None)
Thismethodallowstoregisterfornotificationsonthecharacteristic.
5.2.2.3Bluetooth
310
triggercanmustbeBluetooth.CHAR_NOTIFY_EVENT.
handleristhefunctionthatwillbeexecutedwhenthecallbackistriggered.
argistheargumentthatgetspassedtothecallback.Ifnothingisgiven,the
characteristicobjectthatownsthecallbackwillbeused.
5.2.2.3Bluetooth
311
classGATTSService
TheGATTServerallowsthedevicetoactasaperipheralandholditsownATTlookupdata,
server&characteristicdefinitions.Inthismode,thedeviceactsasaslaveandamaster
mustinitiatearequest.
Servicesareusedtocategorisedataupintospecificchunksofdataknownas
characteristics.Aservicemayhavemultiplecharacteristics,andeachservicehasaunique
numericIDcalledaUUID.
ThefollowingclassallowscontroloverServerservices.
service.start()
Startstheserviceifnotalreadystarted.
service.stop()
Stopstheserviceifpreviouslystarted.
service.characteristic(uuid,*,permissions,properties,value)
Createsanewcharacteristicontheservice.Returnsanobjectoftheclass
GATTSCharacteristic.Theargumentsare:
uuidistheUUIDoftheservice.Cantakeanintegerora16bytelongstringorbytes
object.
permissionsconfiguresthepermissionsofthecharacteristic.Takesanintegerwitha
combinationoftheflags.
propertiessetstheproperties.TakesanintegerwithanOR-edcombinationofthe
flags.
valuesetstheinitialvalue.Cantakeaninteger,astringorabytesobject.
service.characteristic('temp',value=25)
5.2.2.3Bluetooth
312
classGATTSCharacteristic
ThesmallestconceptinGATTistheCharacteristic,whichencapsulatesasingledatapoint
(thoughitmaycontainanarrayofrelateddata,suchasX/Y/Zvaluesfroma3-axis
accelerometer,longitudeandlatitudefromaGPS,etc.).
ThefollowingclassallowsyoutomanageServercharacteristics.
characteristic.value([value])
Getsorsetsthevalueofthecharacteristic.Cantakeaninteger,astringorabytesobject.
characteristic.value(123)#setcharacteristicvaluetoanintegerwiththevalue123
characteristic.value()#getcharacteristicvalue
characteristic.callback(trigger=None,handler=None,arg=None)
Createsacallbackthatwillbeexecutedwhenanyofthetriggersoccurs.Thearguments
are:
triggercanbeeitherBluetooth.CHAR_READ_EVENTor
Bluetooth.CHAR_WRITE_EVENT.
handleristhefunctionthatwillbeexecutedwhenthecallbackistriggered.
argistheargumentthatgetspassedtothecallback.Ifnothingisgiven,the
characteristicobjectthatownsthecallbackwillbeused.
Anexampleofhowthiscouldbeimplementedcanbeseeninthecharacteristic.events()
section.
characteristic.events()
Returnsavaluewithbitflagsidentifyingtheeventsthathaveoccurredsincethelastcall.
Callingthisfunctionclearstheevents.
Anexampleofadvertisingandcreatingservicesonthedevice:
5.2.2.3Bluetooth
313
fromnetworkimportBluetooth
bluetooth=Bluetooth()
bluetooth.set_advertisement(name='LoPy',service_uuid=b'1234567890123456')
defconn_cb(bt_o):
events=bt_o.events()
ifevents&Bluetooth.CLIENT_CONNECTED:
print("Clientconnected")
elifevents&Bluetooth.CLIENT_DISCONNECTED:
print("Clientdisconnected")
bluetooth.callback(trigger=Bluetooth.CLIENT_CONNECTED|Bluetooth.CLIENT_DISCONNECTED,
handler=conn_cb)
bluetooth.advertise(True)
srv1=bluetooth.service(uuid=b'1234567890123456',isprimary=True)
chr1=srv1.characteristic(uuid=b'ab34567890123456',value=5)
char1_read_counter=0
defchar1_cb_handler(chr):
globalchar1_read_counter
char1_read_counter+=1
events=chr.events()
ifevents&Bluetooth.CHAR_WRITE_EVENT:
print("Writerequestwithvalue={}".format(chr.value()))
else:
ifchar1_read_counter<3:
print('Readrequestonchar1')
else:
return'ABCDEF'
char1_cb=chr1.callback(trigger=Bluetooth.CHAR_WRITE_EVENT|Bluetooth.CHAR_READ_EVEN
T,handler=char1_cb_handler)
srv2=bluetooth.service(uuid=1234,isprimary=True)
chr2=srv2.characteristic(uuid=4567,value=0x1234)
char2_read_counter=0xF0
defchar2_cb_handler(chr):
globalchar2_read_counter
char2_read_counter+=1
ifchar2_read_counter>0xF1:
returnchar2_read_counter
char2_cb=chr2.callback(trigger=Bluetooth.CHAR_READ_EVENT,handler=char2_cb_handler)
5.2.2.3Bluetooth
314
5.2.2.3Bluetooth
315
classLoRa
ThisclassprovidesaLoRaWAN1.0.2compliantdriverfortheLoRanetworkprocessorin
theLoPyandFiPy.BelowisanexampledemonstratingLoRaWANActivationby
Personalisationusage:
fromnetworkimportLoRa
importsocket
importubinascii
importstruct
#InitialiseLoRainLORAWANmode.
#Pleasepicktheregionthatmatcheswhereyouareusingthedevice:
#Asia=LoRa.AS923
#Australia=LoRa.AU915
#Europe=LoRa.EU868
#UnitedStates=LoRa.US915
lora=LoRa(mode=LoRa.LORAWAN,region=LoRa.EU868)
#createanABPauthenticationparams
dev_addr=struct.unpack(">l",binascii.unhexlify('00000005'))[0]
nwk_swkey=ubinascii.unhexlify('2B7E151628AED2A6ABF7158809CF4F3C')
app_swkey=ubinascii.unhexlify('2B7E151628AED2A6ABF7158809CF4F3C')
#joinanetworkusingABP(ActivationByPersonalisation)
lora.join(activation=LoRa.ABP,auth=(dev_addr,nwk_swkey,app_swkey))
#createaLoRasocket
s=socket.socket(socket.AF_LORA,socket.SOCK_RAW)
#settheLoRaWANdatarate
s.setsockopt(socket.SOL_LORA,socket.SO_DR,5)
#makethesocketnon-blocking
s.setblocking(False)
#sendsomedata
s.send(bytes([0x01,0x02,0x03]))
#getanydatareceived...
data=s.recv(64)
print(data)
Pleaseensurethatthereisanantennaconnectedtoyourdevicebefore
sending/receivingLoRamessagesasimproperuse(e.g.withoutanantenna),may
damagethedevice.
5.2.2.4LoRa
316
AdditionalExamples
ForvariousothercompleteLoRaexamples,checkhereforadditionalexamples.
Constructors
classnetwork.LoRa(id=0,...)
CreateandconfigureaLoRaobject.Seeinitforparamsofconfiguration.
lora=LoRa(mode=LoRa.LORAWAN,region=LoRa.EU868)
Methods
lora.init(mode,*,region=LoRa.EU868,frequency=868000000,tx_power=14,
bandwidth=LoRa.BW_125KHZ,sf=7,preamble=8,coding_rate=LoRa.CODING_4_5,
power_mode=LoRa.ALWAYS_ON,tx_iq=False,rx_iq=False,adr=False,public=True,
tx_retries=1,device_class=LoRa.CLASS_A)
ThismethodisusedtosettheLoRasubsystemconfigurationandtospecificrawLoRaor
LoRaWAN.
Theargumentsare:
modecanbeeitherLoRa.LORAorLoRa.LORAWAN.
regioncantakethefollowingvalues:LoRa.AS923,LoRa.AU915,LoRa.EU868or
LoRa.US915.Ifnotprovidedthiswilldefaultto LoRaEU868.Iftheyarenotspecified,this
willalsosetappropriatedefaultsfor frequencyand tx_power.
frequencyacceptsvaluesbetween863000000and870000000inthe868band,or
between902000000and928000000inthe915band.
tx_poweristhetransmitpowerindBm.Itacceptsbetween2and14forthe868band,
andbetween5and20inthe915band.
bandwidthisthechannelbandwidthinKHz.Inthe868bandtheacceptedvaluesare
LoRa.BW_125KHZandLoRa.BW_250KHZ.Inthe915bandtheacceptedvaluesare
LoRa.BW_125KHZandLoRa.BW_500KHZ.
sfsetsthedesiredspreadingfactor.Acceptsvaluesbetween7and12.
preambleconfiguresthenumberofpre-amblesymbols.Thedefaultvalueis8.
coding_ratecantakethefollowingvalues:LoRa.CODING_4_5,LoRa.CODING_4_6,
LoRa.CODING_4_7orLoRa.CODING_4_8.
power_modecanbeeitherLoRa.ALWAYS_ON,LoRa.TX_ONLYorLoRa.SLEEP.In
5.2.2.4LoRa
317
ALWAYS_ONmode,theradioisalwayslisteningforincoming-packetswhenevera
transmissionisnottakingplace.InTX_ONLYtheradiogoestosleepassoonasthe
transmissioncompletes.InSLEEPmodetheradioissenttosleeppermanentlyand
won’tacceptanycommandsuntilthepowermodeischanged.
tx_iqenablesTXIQinversion.
rx_iqenablesRXIQinversion.
adrenablesAdaptiveDataRate.
publicselectsbetweenthepublicandprivatesyncword.
tx_retriessetsthenumberofTXretriesinLoRa.LORAWANmode.
device_classsetstheLoRaWANdeviceclass.CanbeeitherLoRa.CLASS_Aor
LoRa.CLASS_C.
InLoRa.LORAWANmode,only adr, public, tx_retriesand device_classare
used.AlltheotherparamswillbeignoredastheyarehandledbytheLoRaWANstack
directly.Ontheotherhand,inLoRa.LORAmodefromthose4arguments,onlythe
publiconeisimportantinordertoprogramthesyncword.InLoRa.LORAmode adr,
tx_retriesand device_classareignoredsincetheyareonlyrelevanttothe
LoRaWANstack.
Forexample,youcando:
#initializeinrawLoRamode
lora.init(mode=LoRa.LORA,tx_power=14,sf=12)
or:
#initializeinLoRaWANmode
lora.init(mode=LoRa.LORAWAN)
lora.join(activation,auth,*,timeout=None,dr=None)
JoinaLoRaWANnetwork.Internallythestackwillautomaticallyretryevery15secondsuntil
aJoinAcceptmessageisreceived.
Theparametersare:
activation:canbeeitherLoRa.OTAAorLoRa.ABP.
auth:isatuplewiththeauthenticationdata.
timeout:isthemaximumtimeinmillisecondstowaitfortheJoinAcceptmessageto
bereceived.Ifnotimeout(orzero)isgiven,thecallreturnsimmediatelyandthestatus
ofthejoinrequestcanbecheckedwith lora.has_joined().
5.2.2.4LoRa
318
dr:isanoptionalvaluetospecifytheinitialdataratefortheJoinRequest.Possible
valuesare0to5forEU868,or0to4forUS915.
InthecaseofLoRa.OTAAtheauthenticationtupleis: (dev_eui,app_eui,app_key)where
dev_euiisoptional.IfitisnotprovidedtheLoRaMACwillbeused.Therefore,youcando
OTAAin2differentways:
lora.join(activation=LoRa.OTAA,auth=(app_eui,app_key),timeout=0)#thedeviceMAC
addressisusedasDEV_EUI
or
lora.join(activation=LoRa.OTAA,auth=(dev_eui,app_eui,app_key),timeout=0)#acusto
mDEV_EUIisspecified
Example:
fromnetworkimportLoRa
importsocket
importtime
importubinascii
#InitialiseLoRainLORAWANmode.
#Pleasepicktheregionthatmatcheswhereyouareusingthedevice:
#Asia=LoRa.AS923
#Australia=LoRa.AU915
#Europe=LoRa.EU868
#UnitedStates=LoRa.US915
lora=LoRa(mode=LoRa.LORAWAN,region=LoRa.EU868)
#createanOTAAauthenticationparameters
app_eui=ubinascii.unhexlify('ADA4DAE3AC12676B')
app_key=ubinascii.unhexlify('11B0282A189B75B0B4D2D8C7FA38548B')
#joinanetworkusingOTAA(OvertheAirActivation)
lora.join(activation=LoRa.OTAA,auth=(app_eui,app_key),timeout=0)
#waituntilthemodulehasjoinedthenetwork
whilenotlora.has_joined():
time.sleep(2.5)
print('Notyetjoined...')
InthecaseofLoRa.ABPtheauthenticationtupleis: (dev_addr,nwk_swkey,app_swkey).
Example:
5.2.2.4LoRa
319
fromnetworkimportLoRa
importsocket
importubinascii
importstruct
#InitialiseLoRainLORAWANmode.
#Pleasepicktheregionthatmatcheswhereyouareusingthedevice:
#Asia=LoRa.AS923
#Australia=LoRa.AU915
#Europe=LoRa.EU868
#UnitedStates=LoRa.US915
lora=LoRa(mode=LoRa.LORAWAN,region=LoRa.EU868)
#createanABPauthenticationparams
dev_addr=struct.unpack(">l",ubinascii.unhexlify('00000005'))[0]
nwk_swkey=ubinascii.unhexlify('2B7E151628AED2A6ABF7158809CF4F3C')
app_swkey=ubinascii.unhexlify('2B7E151628AED2A6ABF7158809CF4F3C')
#joinanetworkusingABP(ActivationByPersonalisation)
lora.join(activation=LoRa.ABP,auth=(dev_addr,nwk_swkey,app_swkey))
lora.bandwidth([bandwidth])
GetorsetthebandwidthinrawLoRamode(LoRa.LORA).CanbeeitherLoRa.BW_125KHZ
(0),LoRa.BW_250KHZ(1)orLoRa.BW_500KHZ(2):
#getrawLoRaBandwidth
lora.bandwidth()
#setrawLoRaBandwidth
lora.bandwidth(LoRa.BW_125KHZ)
lora.frequency([frequency])
GetorsetthefrequencyinrawLoRamode(LoRa.LORA).Theallowedrangeisbetween
863000000and870000000Hzforthe868MHzbandversionorbetween902000000and
928000000Hzforthe915MHzbandversion.
#getrawLoRaFrequency
lora.frequency()
#setrawLoRaFrequency
lora.frequency(868000000)
lora.coding_rate([coding_rate])
5.2.2.4LoRa
320
GetorsetthecodingrateinrawLoRamode(LoRa.LORA).Theallowedvaluesare:
LoRa.CODING_4_5(1),LoRa.CODING_4_6(2),LoRa.CODING_4_7(3)and
LoRa.CODING_4_8(4).
#getrawLoRaCodingRate
lora.coding_rate()
#setrawLoRaCodingRate
lora.coding_rate(LoRa.CODING_4_5)
lora.preamble([preamble])
GetorsetthenumberofpreamblesymbolsinrawLoRamode(LoRa.LORA):
#getrawLoRapreamblesymbols
lora.preamble()
#setrawLoRapreamblesymbols
lora.preamble(LoRa.CODING_4_5)
lora.sf([sf])
GetorsetthespreadingfactorvalueinrawLoRamode(LoRa.LORA).Theminimumvalue
is7andthemaximumis12:
#getrawLoRaspreadfactorvalue
lora.sf()
#setrawLoRaspreadfactorvalue
lora.sf(7)
lora.power_mode([power_mode])
GetorsetthepowermodeinrawLoRamode(LoRa.LORA).Theacceptedvaluesare:
LoRa.ALWAYS_ON,LoRa.TX_ONLYandLoRa.SLEEP:
lora.stats()
ReturnanamedtuplewithusefulinformationfromthelastreceivedLoRaorLoRaWAN
packet.Thenamedtuplehasthefollowingform:
(rx_timestamp,rssi,snr,sftx,sfrx,tx_trials,tx_power,tx_time_on_air,tx_counter,
tx_frequency)
Example:
5.2.2.4LoRa
321
lora.stats()
Where:
rx_timestampisaninternaltimestampofthelastreceivedpacketwithmicroseconds
precision.
rssiholdsthereceivedsignalstrengthindBm.
snrcontainsthesignaltonoiseratioiddB(asasingleprecisionfloat).
sfrxtellsthedatarate(inthecaseofLORAWANmode)orthespreadingfactor(inthe
caseofLORAmode)ofthelastpacketreceived.
sftxtellsthedatarate(inthecaseofLORAWANmode)orthespreadingfactor(inthe
caseofLORAmode)ofthelastpackettransmitted.
tx_trialsisthenumberoftxattemptsofthelasttransmittedpacket(onlyrelevantfor
LORAWANconfirmedpackets).
tx_poweristhepowerofthelasttransmission(indBm).
tx_time_on_airisthetimeonairofthelasttransmittedpacket(inms).
tx_counteristhenumberofpacketstransmitted.
tx_frequencyisthefrequencyusedforthelasttransmission.
lora.has_joined()
Returns TrueifaLoRaWANnetworkhasbeenjoined. Falseotherwise.:
lora.add_channel(index,*,frequency,dr_min,dr_max)
AddaLoRaWANchannelonthespecified index.Ifthere’salreadyachannelwiththat
indexitwillbereplacedwiththenewone.
Theargumentsare:
index:Indexofthechanneltoadd.Acceptsvaluesbetween0and15forEUand
between0and71forUS.
frequency:CentrefrequencyinHzofthechannel.
dr_min:Minimumdatarateofthechannel(0-7).
dr_max:Maximumdatarateofthechannel(0-7).
Examples:
lora.add_channel(index=0,frequency=868000000,dr_min=5,dr_max=6)
lora.remove_channel(index)
5.2.2.4LoRa
322
Removesthechannelfromthespecified index.Onthe868MHzbandthechannels0to2
cannotberemoved,theycanonlybereplacedbyotherchannelsusingthelora.add_channel
method.Awaytoremoveallchannelsexceptforoneistoaddthesamechannel,3timeson
indexes0,1and2.Anexamplecanbeseenbelow:
lora.remove_channel()
Onthe915MHzbandtherearenorestrictionsaroundthis.
lora.mac()
Returnsabyteobjectwiththe8-ByteMACaddressoftheLoRaradio.
lora.callback(trigger,handler=None,arg=None)
SpecifyacallbackhandlerfortheLoRaradio.The triggertypesare
LoRa.RX_PACKET_EVENT,LoRa.TX_PACKET_EVENTandLoRa.TX_FAILED_EVENT
TheLoRa.RX_PACKET_EVENTeventisraisedforeveryreceivedpacket.The
LoRa.TX_PACKET_EVENTeventisraisedassoonasthepackettransmissioncycleends,
whichincludestheendofthereceivewindows(evenifadownlinkisreceived,the
LoRa.TX_PACKET_EVENTwillcomelast).Inthecaseofnon-confirmedtransmissions,this
willoccurattheendofthereceivewindows,but,inthecaseofconfirmedtransmissions,this
eventwillonlyberaisedifthe ackisreceived.Ifthe ackisnotreceived
LoRa.TX_FAILED_EVENTwillberaisedafterthenumberof tx_retriesconfiguredhave
beenperformed.
Anexampleofhowthiscallbackfunctionscanbeseentheinmethodlora.events().
lora.ischannel_free(rssi_threshold)
ThismethodisusedtocheckforradioactivityonthecurrentLoRachannel,andifthe rssi
ofthemeasuredactivityislowerthanthe rssi_thresholdgiven,thereturnvaluewillbe
True,otherwise False.Example:
lora.ischannel_free(-100)
lora.set_battery_level(level)
SetthebatterylevelvaluethatwillbesentwhentheLoRaWANMACcommandthat
retrievesthebatterylevelisreceived.Thiscommandissentbythenetworkandhandled
automaticallybytheLoRaWANstack.ThevaluesshouldbeaccordingtotheLoRaWAN
specification:
5.2.2.4LoRa
323
0meansthattheend-deviceisconnectedtoanexternalpowersource.
1..254specifiesthebatterylevel,1beingatminimumand254beingatmaximum.
255meansthattheend-devicewasnotabletomeasurethebatterylevel.
lora.set_battery_level(127)#50%battery
lora.events()
Thismethodreturnsavaluewithbitssets(ifany)indicatingtheeventsthathavetriggered
thecallback.Pleasenotethatbycallingthisfunctiontheinternaleventsregistryiscleared
automatically,thereforecallingitimmediatelyforasecondtimewillmostlikelyreturnavalue
of0.
Example:
deflora_cb(lora):
events=lora.events()
ifevents&LoRa.RX_PACKET_EVENT:
print('Lorapacketreceived')
ifevents&LoRa.TX_PACKET_EVENT:
print('Lorapacketsent')
lora.callback(trigger=(LoRa.RX_PACKET_EVENT|LoRa.TX_PACKET_EVENT),handler=lora_cb)
lora.nvram_save()
SavetheLoRaWANstate(joinedstatus,networkkeys,packetcounters,etc)innon-volatile
memoryinordertobeabletorestorethestatewhencomingoutofdeepsleeporapower
cycle.
lora.nvram_save()
lora.nvram_restore()
RestoretheLoRaWANstate(joinedstatus,networkkeys,packetcounters,etc)fromnon-
volatilememory.Statemusthavebeenpreviouslystoredwithacallto nvram_savebefore
enteringdeepsleep.ThisisusefultobeabletosendaLoRaWANmessageimmediately
aftercomingoutofdeepsleepwithouthavingtojointhenetworkagain.Thiscanonlybe
usedifthecurrentregionmatchestheonesaved.
lora.nvram_restore()
lora.nvram_erase()
5.2.2.4LoRa
324
RemovetheLoRaWANstate(joinedstatus,networkkeys,packetcounters,etc)fromnon-
volatilememory.
lora.nvram_erase()
Constants
LoRa.LORALoRa.LORAWANLoRastackmode
LoRa.OTAALoRa.ABPLoRaWANjoinprocedure
LoRa.ALWAYS_ONLoRa.TX_ONLYLoRa.SLEEPRawLoRapowermode
LoRa.BW_125KHZLoRa.BW_250KHZLoRa.BW_500KHZRawLoRabandwidth
LoRa.CODING_4_5LoRa.CODING_4_6LoRa.CODING_4_7LoRa.CODING_4_8Raw
LoRacodingrate
LoRa.RX_PACKET_EVENTLoRa.TX_PACKET_EVENTLoRa.TX_FAILED_EVENT
Callbacktriggertypes(maybeORed)
LoRa.CLASS_ALoRa.CLASS_CLoRaWANdeviceclass
LoRa.AS923LoRa.AU915LoRa.EU868LoRa.US915LoRaWANregions
WorkingwithLoRaandLoRaWANSockets
LoRasocketsarecreatedinthefollowingway:
importsocket
s=socket.socket(socket.AF_LORA,socket.SOCK_RAW)
AndtheymustbecreatedafterinitialisingtheLoRanetworkcard.
LoRasocketssupportthefollowingstandardmethodsfromthesocketmodule:
socket.close()
Usage:
s.close()
socket.bind(port_number)
Usage:
5.2.2.4LoRa
325
s.bind(1)
Thebind()methodisonlyapplicablewhentheradioisconfiguredinLoRa.LORAWAN
mode.
socket.send(bytes)
Usage:
s.send(bytes([1,2,3]))
or:
s.send('Hello')
socket.recv(bufsize)
Usage:
s.recv(128)
socket.recvfrom(bufsize)
Thismethodisusefultoknowthedestinationportnumberofthemessagereceived.Returns
atupleoftheform: (data,port)
Usage:
s.recvfrom(128)
socket.setsockopt(level,optname,value)
Setthevalueofthegivensocketoption.Theneededsymbolicconstantsaredefinedinthe
socketmodule( SO_*etc.).InthecaseofLoRathevaluesarealwaysintegers.Examples:
5.2.2.4LoRa
326
#configuringthedatarate
s.setsockopt(socket.SOL_LORA,socket.SO_DR,5)
#selectingnon-confirmedtypeofmessages
s.setsockopt(socket.SOL_LORA,socket.SO_CONFIRMED,False)
#selectingconfirmedtypeofmessages
s.setsockopt(socket.SOL_LORA,socket.SO_CONFIRMED,True)
SocketoptionsareonlyapplicablewhentheLoRaradioisusedinLoRa.LORAWAN
mode.WhenusingtheradioinLoRa.LORAmode,usetheclassmethodstochangethe
spreadingfactor,bandwidthandcodingratetothedesiredvalues.
socket.settimeout(value)
Setsthesockettimeoutvalueinseconds.Acceptsfloatingpointvalues.
Usage:
s.settimeout(5.5)
socket.setblocking(flag)
Usage:
s.setblocking(True)
5.2.2.4LoRa
327
classSigfox
SigfoxisaLowPowerWideAreaNetworkprotocolthatenablesremotedevicestoconnect
usingultra-narrowband,UNBtechnology.Theprotocolisbi-directional,messagescanboth
besentuptoanddownfromtheSigfoxservers.
Whenoperatingin RCZ2and RCZ4themodulecanonlysendmessagesonthedefault
macro-channel(thisisduetoSigfoxnetworklimitations).Therefore,thedeviceneedsto
resetautomaticallytothedefaultmacro-channelafterevery2transmissions.However,
duetoFCCdutycyclelimitations,theremustaminimumofa20sdelayafterresettingto
thedefaultmacro-channel.OurAPItakescareofthis,(andinreallifeapplicationsyou
shouldnotbeintheneedtosendSigfoxmessagesthatoften),soitwillwaitforthe
necessaryamountoftimetomakesurethatthedutycyclerestrictionsarefulfilled.
Thismeansthatifyourunapieceoftestcodelike:
foriinrange(1,100):
#sendsomething
s.send('Hello'+str(i))
Therewillbea20seconddelayafterevery2packets.
ThisclassprovidesadriverfortheSigfoxnetworkprocessorintheSigfoxenabledPycom
devices.
QuickUsageExample
5.2.2.5Sigfox
328
fromnetworkimportSigfox
importsocket
#initSigfoxforRCZ1(Europe)
sigfox=Sigfox(mode=Sigfox.SIGFOX,rcz=Sigfox.RCZ1)
#createaSigfoxsocket
s=socket.socket(socket.AF_SIGFOX,socket.SOCK_RAW)
#makethesocketblocking
s.setblocking(True)
#configureitasuplinkonly
s.setsockopt(socket.SOL_SIGFOX,socket.SO_RX,False)
#sendsomebytes
s.send(bytes([1,2,3,4,5,6,7,8,9,10,11,12]))
Pleaseensurethatthereisanantennaconnectedtoyourdevicebefore
sending/receivingSigfoxmessagesasinproperuse(e.g.withoutanantenna),may
damagethedevice.
Constructors
classnetwork.Sigfox(id=0,...)
CreateandconfigureaSigfoxobject.Seeinitforparamsofconfiguration.Examples:
#configureradiofortheSigfoxnetwork,usingRCZ1(868MHz)
sigfox=Sigfox(mode=Sigfox.SIGFOX,rcz=Sigfox.RCZ1)
#configureradioforFSK,devicetodeviceacross912MHz
sigfox=Sigfox(mode=Sigfox.FSK,frequency=912000000)
Methods
sigfox.init(mode=Sigfox.SIGFOX,rcz=Sigfox.RCZ1,*,frequency=None)
SettheSigfoxradioconfiguration.
Theargumentsare:
modecanbeeitherSigfox.SIGFOXorSigfox.FSK.Sigfox.SIGFOXusestheSigfox
modulationandprotocolwhileSigfox.FSKallowstocreatepointtopointcommunication
5.2.2.5Sigfox
329
between2DevicesusingFSKmodulation.
rcztakesthefollowingvalues:Sigfox.RCZ1,Sigfox.RCZ2,Sigfox.RCZ3,
Sigfox.RCZ4.The rczargumentisonlyrequiredifthemodeisSigfox.SIGFOX.
frequencysetsthefrequencyvaluein FSKmode.Cantakevaluesbetween863and
928MHz.
TheSiPycomesin2differenthardwareflavours:a+14dBmTxpowerversionwhichcan
onlyworkwith RCZ1and RCZ3anda+22dBmversionwhichworksexclusivelyon
RCZ2and RCZ4.
sigfox.mac()
Returnsabyteobjectwiththe8-ByteMACaddressoftheSigfoxradio.
sigfox.id()
Returnsabyteobjectwiththe4-BytebytesobjectwiththeSigfoxID.
sigfox.rssi()
Returnsasignedintegerwithindicatingthesignalstrengthvalueofthelastreceivedpacket.
sigfox.pac()
Returnsabyteobjectwiththe8-BytebytesobjectwiththeSigfoxPAC.
Toreturnhuman-readablevaluesyoushouldimport ubinasciiandconvertbinary
valuestohexidecimalrepresentation.Forexample:
print(ubinascii.hexlify(sigfox.mac()))
sigfox.frequencies()
Returnsatupleoftheform: (uplink_frequency_hz,downlink_frequency_hz)
sigfox.public_key([public])
Setsorgetsthepublickeyflag.Whencalledpassinga TruevaluetheSigfoxpublickey
willbeusedtoencryptthepackets.Callingitwithoutargumentsreturnsthestateoftheflag.
5.2.2.5Sigfox
330
#enableencryptedpackets
sigfox.public_key(True)
#returnstateofpublic_key
sigfox.public_key()
Constants
sigfox.SIGFOXsigfox.FSKSigfoxradiomode.SIGFOXtospecifyusageoftheSigfoxPublic
Network. FSKtospecifydevicetodevicecommunication.
sigfox.RCZ1sigfox.RCZ2sigfox.RCZ3sigfox.RCZ4Sigfoxzones.
RCZ1tospecifyEurope,Oman&SouthAfrica.
RCZ2fortheUSA,Mexico&Brazil.RCZ3forJapan.
RCZ4forAustralia,NewZealand,Singapore,Taiwan,HongKong,Colombia&
Argentina.
WorkingwithSigfoxSockets
Sigfoxsocketsarecreatedinthefollowingway:
importsocket
s=socket.socket(socket.AF_SIGFOX,socket.SOCK_RAW)
AndtheymustbecreatedafterinitialisingtheSigfoxnetworkcard.
Sigfoxsocketssupportthefollowingstandardmethodsfromthe socketmodule:
socket.close()
Useittocloseanexistingsocket.
socket.send(bytes)
InSigfoxmodethemaximumdatasizeis12bytes.InFSKthemaximumis64.
#sendaSigfoxpayloadofbytes
s.send(bytes([1,2,3]))
#sendaSigfoxpayloadcontainingastring
s.send('Hello')
socket.recv(bufsize)
5.2.2.5Sigfox
331
ThismethodcanbeusedtoreceiveaSigfoxdownlinkorFSKmessage.
#sizeofbuffershouldbepassedforexpectedpayload,e.g.64bytes
s.recv(64)
socket.setsockopt(level,optname,value)
Setthevalueofthegivensocketoption.Theneededsymbolicconstantsaredefinedinthe
socketmodule( SO_*etc.).InthecaseofSigfoxthevaluesarealwaysaninteger.
Examples:
#waitforadownlinkaftersendingtheuplinkpacket
s.setsockopt(socket.SOL_SIGFOX,socket.SO_RX,True)
#makethesocketuplinkonly
s.setsockopt(socket.SOL_SIGFOX,socket.SO_RX,False)
#usethesockettosendaSigfoxOutOfBandmessage
s.setsockopt(socket.SOL_SIGFOX,socket.SO_OOB,True)
#disableOut-Of-Bandtousethesocketnormally
s.setsockopt(socket.SOL_SIGFOX,socket.SO_OOB,False)
#selectthebitvaluewhensendingbitonlypackets
s.setsockopt(socket.SOL_SIGFOX,socket.SO_BIT,False)
SendingaSigfoxpacketwithasinglebitisachievedbysendinganemptystring,i.e.:
importsocket
s=socket.socket(socket.AF_SIGFOX,socket.SOCK_RAW)
#senda1bit
s.setsockopt(socket.SOL_SIGFOX,socket.SO_BIT,True)
s.send('')
socket.settimeout(value)
#settimeoutforthesocket,e.g.5seconds
s.settimeout(5.0)
socket.setblocking(flag)
#specifiesifsocketshouldbeblockingbaseduponBooleanflag.
s.setblocking(True)
Ifthesocketissettoblocking,yourcodewillbewaituntilthesocketcompletes
sending/receiving.
SigfoxDownlink
5.2.2.5Sigfox
332
ASigfoxcapablePycomdevices(SiPy)canbothsendandreceivedatafromtheSigfox
network.Toreceivedata,amessagemustfirstbesentuptoSigfox,requestingadownlink
message.Thiscanbedonebypassinga Trueargumentintothe setsockopt()method.
s.setsockopt(socket.SOL_SIGFOX,socket.SO_RX,True)
Anexampleofthedownlinkprocedurecanbeseenbelow:
#initSigfoxforRCZ1(Europe)
sigfox=Sigfox(mode=Sigfox.SIGFOX,rcz=Sigfox.RCZ1)
#createaSigfoxsocket
s=socket.socket(socket.AF_SIGFOX,socket.SOCK_RAW)
#makethesocketblocking
s.setblocking(True)
#configureitasDOWNLINKspecifiedby'True'
s.setsockopt(socket.SOL_SIGFOX,socket.SO_RX,True)
#sendsomebytesandrequestDOWNLINK
s.send(bytes([1,2,3]))
#awaitDOWNLINKmessage
s.recv(32)
SigfoxFSK(DevicetoDevice)
TocommunicatebetweentwoSigfoxcapabledevices,itmaybeusedinFSKmode.Two
devicesarerequiredtobesettothesamefrequency,bothusingFSK.
Device1:
sigfox=Sigfox(mode=Sigfox.FSK,frequency=868000000)
s=socket.socket(socket.AF_SIGFOX,socket.SOCK_RAW)
s.setblocking(True)
whileTrue:
s.send('Device-1')
time.sleep(1)
print(s.recv(64))
Device2:
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333
sigfox=Sigfox(mode=Sigfox.FSK,frequency=868000000)
s=socket.socket(socket.AF_SIGFOX,socket.SOCK_RAW)
s.setblocking(True)
whileTrue:
s.send('Device-2')
time.sleep(1)
print(s.recv(64))
Remembertousethecorrectfrequencyforyourregion(868MHzforEurope,912MHz
forUSA,etc.)
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334
classLTE
TheLTEclassprovidesaccesstotheLTE-M/NB-IoTmodemontheGPyandFiPy.LTE-
M/NB-IoTarenewcategoriesofcellularprotocolsdevelopedbythe3GPPandoptimisedfor
longbatterylifepowerandlongerrange.Thesearenewprotocolscurrentlyintheprocessof
beingdeployedbymobilenetworksacrosstheworld.
TheGPyandFiPysupportbothnewLTE-Mprotocols:
Cat-M1:alsoknownasLTE-Mdefinesa1.4MHzradiochannelsizeandabout375
kbpsofthroughput.Itisoptimisedforcoverageandlongbatterylife,outperforming
2G/GPRS,whilebeingsimilartopreviousLTEstandards.
Cat-NB1alsoknownasNB-IoT,definesa200kHzradiochannelsizeandaround60
kbpsofuplinkspeed.It'soptimisedforultralowthroughputandspecificallydesignedfor
IoTdeviceswithaverylongbatterylife.NB-IoTsharessomefeatureswithLTEsuchas
operatinginlicensedspectrum,butit'saverydifferentprotocol.Itshouldbenotedthat
NB-IoThasmanyrestrictionsasdoesnotofferfullIPconnectivityanddoesnotsupport
mobility.Whenmovingbetweencells,youwillneedtoreconnect.
Pleasenote:TheGPyandFiPyonlysupportthetwoprotocolsaboveandarenot
compatiblewitholderLTEstandards.
TheSequansmodemusedonPycom'scellularenabledmodulescanonlyworkinone
ofthesemodesatatime.Inordertoswitchbetweenthetwoprotocolsyouneedtoflash
adifferentfirmwaretotheSequansmodem.Instructionsforthiscanbefoundhere.
ATCommands
TheATcommandsfortheSequansMonarchmodemontheGPy/FiPyareavailableina
PDFfile.
Constructors
classnetwork.LTE(id=0,...)
CreateandconfigureaLTEobject.Seeinitforparamsofconfiguration.
5.2.2.6LTE
335
fromnetworkimportLTE
lte=LTE()
Methods
lte.init(*,carrier=None)
ThismethodisusedtosetuptheLTEsubsystem.Aftera deinit()thismethodcantake
severalsecondstoreturnwaitingfortheLTEmodemtostart-up.Optionallyspecifyacarrier
name.Theavailableoptionsare: verizon,at&t,standard. standardisgenericforany
carrier,andit'salsotheoptionusedwhennoargumentsaregiven.
lte.deinit()
DisablesLTEmodemcompletely.Thisreducesthepowerconsumptiontotheminimum.Call
thisbeforeenteringdeepsleep.
lte.attach(*,band=None)
EnableradiofunctionalityandattachtotheLTECatM1networkauthorisedbytheinserted
SIMcard.Optionallyspecifythebandtoscanfornetworks.Ifnoband(or None)is
specified,all6bandswillbescanned.Thepossiblevaluesforthebandare: 3,4,12,13,
20and28.
lte.isattached()
Returns Trueifthecellularmodeisattachedtothenetwork. Falseotherwise.
lte.dettach()
DetachthemodemfromtheLTECatM1anddisabletheradiofunctionality.
lte.connect(*,cid=1)
StartadatasessionandobtainandIPaddress.OptionallyspecifyaCID(ConnectionID)for
thedatasession.Theargumentsare:
-`cid`isaConnectionID.Thisiscarrierspecific,forVerizonuse`cid=3`.Foroth
erslikeTelstraitshouldbe`cid=1`.
Forinstance,toattachandconnecttoVerizon:
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336
importtime
fromnetworkimportLTE
lte=LTE(carrier="verizon")
lte.attach(band=13)
whilenotlte.isattached():
time.sleep(0.5)
print('Attaching...')
lte.connect(cid=3)
whilenotlte.isconnected():
time.sleep(0.5)
print('Connecting...')
#Nowusesocketsasusual...
lte.isconnected()
Returns TrueifthereisanactiveLTEdatasessionandIPaddresshasbeenobtained.
Falseotherwise.
lte.disconnect()
Endthedatasessionwiththenetwork.
lte.send_at_cmd(cmd)
SendanATcommanddirectlytothemodem.Returnstherawresponsefromthemodemas
astringobject.IMPORTANT:Ifadatasessionisactive(i.e.themodemisconnected),
sendingtheATcommandsrequirestopauseandthenresumethedatasession.Thisisall
doneautomatically,butmakesthewholerequesttakearound2.5seconds.
Example:
lte.send_at_cmd('AT+CEREG?')#checkfornetworkregistrationmanually(samesaslt
e.isattached())
Optionallytheresponsecanbeparsedforprettyprinting:
defsend_at_cmd_pretty(cmd):
response=lte.send_at_cmd(cmd).split('\r\n')
forlineinresponse:
print(line)
send_at_cmd_pretty('AT!="showphy"')#getthePHYstatus
send_at_cmd_pretty('AT!="fsm"')#gettheSystemFSM
5.2.2.6LTE
337
lte.imei()
ReturnsastringobjectwiththeIMEInumberoftheLTEmodem.
lte.iccid()
ReturnsastringobjectwiththeICCIDnumberoftheSIMcard.
lte.reset()
Performahardwareresetonthecellularmodem.Thisfunctioncantakeupto5secondsto
returnasitwaitsforthemodemtoshutdownandreboot.
5.2.2.6LTE
338
classAES-AdvancedEncryption
Standard
AES(AdvancedEncryptionStandard)isasymmetricblockcipherstandardisedbyNIST.It
hasafixeddatablocksizeof16bytes.Itskeyscanbe128,192,or256bitslong.
AESisimplementedusingtheESP32hardwaremodule.
QuickUsageExample
fromcryptoimportAES
importcrypto
key=b'notsuchsecretkey'#128bit(16bytes)key
iv=crypto.getrandbits(128)#hardwaregeneratedrandomIV(neverreuseit)
cipher=AES(key,AES.MODE_CFB,iv)
msg=iv+cipher.encrypt(b'Attackatdawn')
#...afterproperlysenttheencryptedmessagesomewhere...
cipher=AES(key,AES.MODE_CFB,msg[:16])#onthedecryptionside
original=cipher.decrypt(msg[16:])
print(original)
Constructors
classucrypto.AES(key,mode,IV,*,counter,segment_size)
CreateanAESobjectthatwillletyouencryptanddecryptmessages.
Theargumentsare:
key(bytestring)isthesecretkeytouse.Itmustbe16(AES-128),24(AES-192),or
32(AES-256)byteslong.
modeisthechainingmodetouseforencryptionanddecryption.Defaultis
AES.MODE_ECB.
IV(bytestring)initialisationvector.Shouldbe16byteslong.Itisignoredinmodes
AES.MODE_ECBandAES.MODE_CRT.
counter(bytestring)usedonlyforAES.MODE_CTR.Shouldbe16byteslong.Should
notbereused.
5.2.3AES
339
segment_sizeisthenumberofbits plaintextand ciphertextaresegmentedin.Is
onlyusedinAES.MODE_CFB.SupportedvaluesareAES.SEGMENT_8and
AES.SEGMENT_128.
Methods
ucrypto.encrypt()
Encryptdatawiththekeyandtheparameterssetatinitialisation.
ucrypto.decrypt()
Decryptdatawiththekeyandtheparameterssetatinitialisation.
Constants
AES.MODE_ECB
ElectronicCodeBook.Simplestencryptionmode.Itdoesnothidedatapatternswell(see
thisarticleformoreinfo).
AES.MODE_CBC
Cipher-BlockChaining.AnInitialisationVector(IV)isrequired.
AES.MODE_CFB
Cipherfeedback. plaintextand ciphertextareprocessedinsegmentsof segment_size
bits.Worksastreamcipher.
AES.MODE_CTR
Countermode.Eachmessageblockisassociatedtoacounterwhichmustbeuniqueacross
allmessagesthatgetencryptedwiththesamekey.
AES.SEGMENT_8AES.SEGMENT_128
LengthofthesegmentforAES.MODE_CFB.
Toavoidsecurityissues,IVshouldalwaysbearandomnumberandshouldneverbe
reusedtoencrypttwodifferentmessages.ThesameappliestothecounterinCTR
mode.Youcanusecrypto.getrandbits()forthispurpose.
5.2.3AES
340
pycom–PycomDeviceFeatures
The pycommodulecontainsfunctionstocontrolspecificfeaturesofthePycomdevices,
suchastheheartbeatRGBLED.
QuickUsageExample
importpycom
pycom.heartbeat(False)#disabletheheartbeatLED
pycom.heartbeat(True)#enabletheheartbeatLED
pycom.heartbeat()#gettheheartbeatstate
pycom.rgbled(0xff00)#maketheLEDlightupingreencolor
Functions
pycom.heartbeat([enable])
Getorsetthestate(enabledordisabled)oftheheartbeatLED.Acceptsandreturnsboolean
values( Trueor False).
pycom.heartbeat_on_boot([enable])
AllowsyoupermanentlydisableorenabletheheartbeatLED.Oncethissettingisset,itwill
persistbetweenreboots.Note,thisonlycomesintoeffectonthenextboot,itdoesnotstop
thealreadyrunningheartbeat.
pycom.rgbled(color)
SetthecolouroftheRGBLED.Thecolourisspecifiedas24bitvaluerepresentingred,
greenandblue,wheretheredcolourisrepresentedbythe8mostsignificantbits.For
instance,passingthevalue 0x00FF00willlightuptheLEDinaverybrightgreen.
pycom.nvs_set(key,value)
SetthevalueofthespecifiedkeyintheNVRAMmemoryareaoftheexternalflash.Data
storedhereispreservedacrossresetsandpowercycles.Valuecanonlytake32-bitintegers
atthemoment.Example:
5.2.4pycom
341
importpycom
pycom.nvs_set('temp',25)
pycom.nvs_set('count',10)
pycom.nvs_get(key)
GetthevaluethespecifiedkeyfromtheNVRAMmemoryareaoftheexternalflash.
Example:
importpycom
pulses=pycom.nvs_get('count')
Ifanon-existingkeyisgiventhereturnedvaluewillbe None.
pycom.nvs_erase(key)
ErasethegivenkeyfromtheNVRAMmemoryarea.
pycom.nvs_erase_all()
ErasetheentireNVRAMmemoryarea.
pycom.wifi_on_boot([enable])
GetorsettheWiFionbootflag.Whenthisflagissetto True,theAPwiththedefaultSSID
(lopy-wlan-xxxforexample)willbeenabledaspartofthebootprocess.Iftheflagissetto
False,themodulewillbootwithWiFidisableduntilit'senabledbythescriptviathe WLAN
class.Thissettingisstoredinnon-volatilememorywhichpreservesitacrossresetsand
powercycles.Example:
importpycom
pycom.wifi_on_boot(True)#enableWiFionboot
pycom.wifi_on_boot()#getthewifionbootflag
pycom.wdt_on_boot([enable])
EnablestheWDTatboottimewiththetimeoutinmssetbythefunction
wdt_on_boot_timeout.Ifthisflagisset,theapplicationneedstoreconfiguretheWDTwitha
newtimeoutandfeeditregularlytoavoidareset.
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importpycom
pycom.wdt_on_boot(True)#enableWDTonboot
pycom.wdt_on_boot()#gettheWDTonbootflag
pycom.wdt_on_boot_timeout([timeout])
SetsorgetstheWDTonboottimeoutinmilliseconds.Theminimumvalueis5000ms.
importpycom
pycom.wdt_on_boot_timeout(10000)#setthetimeoutto5000ms
pycom.wdt_on_boot_timeout()#gettheWDTtimeoutvalue
pycom.pulses_get(pin,timeout)
Returnalistofpulsesat pin.Themethodsscansfortransitionsat pinandreturnsalist
oftuples,eachtellingthepinvalueandthedurationinmicrosecondsofthatvalue. pinisa
pinobject,whichmusthavesetto INPor OPEN_DRAINmode.Thescanstopsifnot
transitionsoccurswithin timeoutmilliseconds.
Example:
#gettherawdatafromaDHT11/DHT22/AM2302sensor
frommachineimportPin
frompycomimportpulses_get
fromtimeimportsleep_ms
pin=Pin("G7",mode=Pin.OPEN_DRAIN)
pin(0)
sleep_ms(20)
pin(1)
data=pulses_get(pin,100)
pycom.ota_start()
pycom.ota_write(buffer)
pycom.ota_finish()
Performafirmwareupdate.Thesemethodsareinternallyusedbyafirmwareupdatethough
FTP.Theupdatestartswithacallto ota_start(),followedbyaseriesofcallsto
ota_write(buffer),andisterminatedwith ota_finish().Afterreset,thenewimagegets
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active. buffershallholdtheimagedatatobewritten,inarbitrarysizes.Ablocksizeof
4096isrecommended.
Example:
#FirmwareupdatebyreadingtheimagefromtheSDcard
#
frompycomimportota_start,ota_write,ota_finish
fromosimportmount
frommachineimportSD
BLOCKSIZE=const(4096)
APPIMG="/sd/appimg.bin"
sd=SD()
mount(sd,'/sd')
withopen(APPIMG,"rb")asf:
buffer=bytearray(BLOCKSIZE)
mv=memoryview(buffer)
size=0
ota_start()
whileTrue:
chunk=f.readinto(buffer)
ifchunk>0:
ota_write(mv[:chunk])
size+=chunk
print("\r%7d"%size,end="")
else:
break
ota_finish()
Insteadofreadingthedatatobewrittenfromafile,itcanobviouslyalsobereceivedfroma
serverusinganysuitableprotocol,withouttheneedtostoreitinthedevicesfilesystem.
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Micropythonlibraries
ThefollowinglistcontainsthestandardPythonlibraries,MicroPython-specificlibrariesand
PycomspecificmodulesthatareavailableonthePycomdevices.
ThestandardPythonlibrarieshavebeen"micro-ified"tofitinwiththephilosophyof
MicroPython.Theyprovidethecorefunctionalityofthatmoduleandareintendedtobea
drop-inreplacementforthestandardPythonlibrary.
Somemodulesareavailablebyanu-name,andalsobytheirnon-u-name.Thenon-u-
namecanbeoverriddenbyafileofthatnameinyourpackagepath.Forexample,
importjsonwillfirstsearchforafile json.pyordirectory jsonandloadthat
packageifit'sfound.Ifnothingisfound,itwillfallbacktoloadingthebuilt-in ujson
module.
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classmicropython–MicroPythonInternals
Controls
Functions
micropython.alloc_emergency_exception_buf(size)
AllocatesizebytesofRAMfortheemergencyexceptionbuffer(agoodsizeisaround100
bytes).ThebufferisusedtocreateexceptionsincaseswhennormalRAMallocationwould
fail(egwithinaninterrupthandler)andthereforegiveusefultracebackinformationinthese
situations.
Agoodwaytousethisfunctionistoplaceitatthestartofamainscript(e.g. boot.pyor
main.py)andthentheemergencyexceptionbufferwillbeactiveforallthecodefollowingit.
micropython.const(expr)
Usedtodeclarethattheexpressionisaconstantsothatthecompilecanoptimiseit.The
useofthisfunctionshouldbeasfollows:
frommicropythonimportconst
CONST_X=const(123)
CONST_Y=const(2*CONST_X+1)
Constantsdeclaredthiswayarestillaccessibleasglobalvariablesfromoutsidethemodule
theyaredeclaredin.Ontheotherhand,ifaconstantbeginswithanunderscorethenitis
hidden,itisnotavailableasaglobalvariable,anddoesnottakeupanymemoryduring
execution.
ThisconstfunctionisrecogniseddirectlybytheMicroPythonparserandisprovidedaspart
ofthe micropythonmodulemainlysothatscriptscanbewrittenwhichrununderboth
CPythonandMicroPython,byfollowingtheabovepattern.
micropython.opt_level([level])
If levelisgiventhenthisfunctionsetstheoptimisationlevelforsubsequentcompilationof
scripts,andreturns None.Otherwiseitreturnsthecurrentoptimisationlevel.
micropython.mem_info([verbose])
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Printinformationaboutcurrentlyusedmemory.Ifthe verboseargumentisgiventhenextra
informationisprinted.
Theinformationthatisprintedisimplementationdependent,butcurrentlyincludesthe
amountofstackandheapused.Inverbosemodeitprintsouttheentireheapindicating
whichblocksareusedandwhicharefree.
micropython.qstr_info([verbose])
Printinformationaboutcurrentlyinternedstrings.Ifthe verboseargumentisgiventhen
extrainformationisprinted.
Theinformationthatisprintedisimplementationdependent,butcurrentlyincludesthe
numberofinternedstringsandtheamountofRAMtheyuse.Inverbosemodeitprintsout
thenamesofallRAM-internedstrings.
micropython.stack_use()
Returnanintegerrepresentingthecurrentamountofstackthatisbeingused.Theabsolute
valueofthisisnotparticularlyuseful,ratheritshouldbeusedtocomputedifferencesin
stackusageatdifferentpoints.
micropython.heap_lock()
micropython.heap_unlock()
Lockorunlocktheheap.Whenlockednomemoryallocationcanoccuranda MemoryError
willberaisedifanyheapallocationisattempted.
Thesefunctionscanbenested,i.e. heap_lock()canbecalledmultipletimesinarowand
thelock-depthwillincrease,andthen heap_unlock()mustbecalledthesamenumberof
timestomaketheheapavailableagain.
micropython.kbd_intr(chr)
Setthecharacterthatwillraisea KeyboardInterruptexception.Bydefaultthisissetto3
duringscriptexecution,correspondingto Ctrl-C.Passing -1tothisfunctionwilldisable
captureof Ctrl-C,andpassing 3willrestoreit.
Thisfunctioncanbeusedtopreventthecapturingof Ctrl-Contheincomingstreamof
charactersthatisusuallyusedfortheREPL,incasethatstreamisusedforotherpurposes.
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uctypes–AccessBinaryDataina
StructuredFormat
Thismoduleimplements"foreigndatainterface"forMicroPython.Theideabehinditis
similartoCPython’s ctypesmodules,buttheactualAPIisdifferent,streamlinedand
optimisedforsmallsize.Thebasicideaofthemoduleistodefinedatastructurelayoutwith
aboutthesamepowerastheClanguageallows,andtheaccessitusingfamiliardot-syntax
toreferencesub-fields.
ModuleustructStandardPythonwaytoaccessbinarydatastructures(doesn’tscale
welltolargeandcomplexstructures).
DefiningStructureLayout
Structurelayoutisdefinedbya"descriptor"-aPythondictionarywhichencodesfieldnames
askeysandotherpropertiesrequiredtoaccessthemasassociatedvalues.Currently,
uctypesrequiresexplicitspecificationofoffsetsforeachfield.Offsetaregiveninbytesfrom
astructurestart.
Followingareencodingexamplesforvariousfieldtypes:
Scalartypes:
"field_name":uctypes.UINT32|0
Inotherwords,valueisscalartypeidentifierOR-edwithfieldoffset(inbytes)fromthestart
ofthestructure.
Recursivestructures:
"sub":(2,{
"b0":uctypes.UINT8|0,
"b1":uctypes.UINT8|1,
})
I.e.valueisa2-tuple,firstelementofwhichisoffset,andsecondisastructuredescriptor
dictionary(note:offsetsinrecursivedescriptorsarerelativetoastructureitdefines).
ArraysofPrimitiveTypes:
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348
"arr":(uctypes.ARRAY|0,uctypes.UINT8|2),
I.e.valueisa2-tuple,firstelementofwhichisARRAYflagOR-edwithoffset,andsecondis
scalarelementtypeOR-ednumberofelementsinarray.
ArraysofAggregateTypes:
"arr2":(uctypes.ARRAY|0,2,{"b":uctypes.UINT8|0}),
I.e.valueisa3-tuple,firstelementofwhichisARRAYflagOR-edwithoffset,secondisa
numberofelementsinarray,andthirdisdescriptorofelementtype.
Pointertoaprimitivetype:
"ptr":(uctypes.PTR|0,uctypes.UINT8),
I.e.valueisa2-tuple,firstelementofwhichisPTRflagOR-edwithoffset,andsecondis
scalarelementtype.
Pointertoanaggregatetype:
"ptr2":(uctypes.PTR|0,{"b":uctypes.UINT8|0}),
I.e.valueisa2-tuple,firstelementofwhichisPTRflagOR-edwithoffset,secondis
descriptoroftypepointedto.
Bitfields:
"bitf0":uctypes.BFUINT16|0|0<<uctypes.BF_POS|8<<uctypes.BF_LEN,
I.e.valueistypeofscalarvaluecontaininggivenbitfield(typenamesaresimilartoscalar
types,butprefixeswith"BF"),OR-edwithoffsetforscalarvaluecontainingthebitfield,and
furtherOR-edwithvaluesforbitoffsetandbitlengthofthebitfieldwithinscalarvalue,
shiftedbyBF_POSandBF_LENpositions,respectively.Bitfieldpositioniscountedfromthe
leastsignificantbit,andisthenumberofright-mostbitofafield(inotherwords,it’sa
numberofbitsascalarneedstobeshiftedrighttoextrathebitfield).
Intheexampleabove,first UINT16valuewillbeextractedatoffset0(thisdetailmaybe
importantwhenaccessinghardwareregisters,whereparticularaccesssizeandalignment
arerequired),andthenbitfieldwhoserightmostbitisleast-significantbitofthis UINT16,and
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349
lengthis8bits,willbeextracted-effectively,thiswillaccessleast-significantbyteof
UINT16.
Notethatbitfieldoperationsareindependentoftargetbyteendianness,inparticular,
exampleabovewillaccessleast-significantbyteof UINT16inbothlittle-andbig-endian
structures.Butitdependsontheleastsignificantbitbeingnumbered0.Sometargetsmay
usedifferentnumberingintheirnativeABI,but uctypesalwaysusesnormalisednumbering
describedabove.
ModuleContents
classuctypes.struct(addr,descriptor,layout_type=NATIVE)
Instantiatea"foreigndatastructure"objectbasedonstructureaddressinmemory,
descriptor(encodedasadictionary),andlayouttype(seebelow).
uctypes.LITTLE_ENDIAN
Layouttypeforalittle-endianpackedstructure.(Packedmeansthateveryfieldoccupies
exactlyasmanybytesasdefinedinthedescriptor,i.e.thealignmentis1).
uctypes.BIG_ENDIAN
Layouttypeforabig-endianpackedstructure.
uctypes.NATIVE
Layouttypeforanativestructure-withdataendiannessandalignmentconformingtothe
ABIofthesystemonwhichMicroPythonruns.
uctypes.sizeof(struct)
Returnsizeofdatastructureinbytes.Argumentcanbeeitherstructureclassorspecific
instantiatedstructureobject(oritsaggregatefield).
uctypes.addressof(obj)
Returnaddressofanobject.Argumentshouldbebytes, bytearrayorotherobject
supportingbufferprotocol(andaddressofthisbufferiswhatactuallyreturned).
uctypes.bytes_at(addr,size)
Capturememoryatthegivenaddressandsizeasbytesobject.Asbytesobjectis
immutable,memoryisactuallyduplicatedandcopiedintobytesobject,soifmemory
contentschangelater,createdobjectretainsoriginalvalue.
5.3.2uctypes
350
uctypes.bytearray_at(addr,size)
Capturememoryatthegivenaddressandsizeas bytearrayobject.Unlike bytes_at()
functionabove,memoryiscapturedbyreference,soitcanbebothwrittentoo,andyouwill
accesscurrentvalueatthegivenmemoryaddress.
StructureDescriptorsandInstantiatingStructureObjects
Givenastructuredescriptordictionaryanditslayouttype,youcaninstantiateaspecific
structureinstanceatagivenmemoryaddressusinguctypes.struct()constructor.Memory
addressusuallycomesfromfollowingsources:
Predefinedaddress,whenaccessinghardwareregistersonabaremetalsystem.
LookuptheseaddressesindatasheetforaparticularMCU/SoC.
AsareturnvaluefromacalltosomeFFI(ForeignFunctionInterface)function.
Fromuctypes.addressof(),whenyouwanttopassargumentstoanFFIfunction,or
alternatively,toaccesssomedataforI/O(forexample,datareadfromafileornetwork
socket).
Structureobjects
Structureobjectsallowaccessingindividualfieldsusingstandarddotnotation:
my_struct.substruct1.field1.Ifafieldisofscalartype,gettingitwillproduceaprimitive
value(Pythonintegerorfloat)correspondingtothevaluecontainedinafield.Ascalarfield
canalsobeassignedto.
Ifafieldisanarray,itsindividualelementscanbeaccessedwiththestandardsubscript
operator []-bothreadandassignedto.
Ifafieldisapointer,itcanbedereferencedusing [0]syntax(correspondingtoC *
operator,though [0]worksinCtoo).Subscriptingapointerwithotherintegervaluesbut0
aresupportedtoo,withthesamesemanticsasinC.
Summingup,accessingstructurefieldsgenerallyfollowsCsyntax,exceptforpointer
dereference,whenyouneedtouse [0]operatorinsteadof *.
Limitations
Accessingnon-scalarfieldsleadstoallocationofintermediateobjectstorepresentthem.
Thismeansthatspecialcareshouldbetakentolayoutastructurewhichneedstobe
accessedwhenmemoryallocationisdisabled(e.g.fromaninterrupt).The
recommendationsare:
5.3.2uctypes
351
Avoidnestedstructures.Forexample,insteadof
mcu_registers.peripheral_a.register1,defineseparatelayoutdescriptorsforeach
peripheral,tobeaccessedas peripheral_a.register1.
Avoidothernon-scalardata,likearray.Forexample,insteadof
peripheral_a.register[0]use peripheral_a.register0.
Notethattheserecommendationswillleadtodecreasedreadabilityandconcisenessof
layouts,sotheyshouldbeusedonlyiftheneedtoaccessstructurefieldswithoutallocation
isanticipated(it’sevenpossibletodefine2parallellayouts-onefornormalusage,anda
restrictedonetousewhenmemoryallocationisprohibited).
5.3.2uctypes
352
sys–SystemSpecificFunctions
Functions
sys.exit(retval=0)
Terminatecurrentprogramwithagivenexitcode.Underlyingly,thisfunctionraiseas
SystemExitexception.Ifanargumentisgiven,itsvaluegivenasanargumentto
SystemExit.
sys.print_exception(exc,file=sys.stdout)
Printexceptionwithatracebacktoafile-likeobjectfile(or sys.stdoutbydefault).
DifferencetoCPython
Thisissimplifiedversionofafunctionwhichappearsinthetracebackmodulein
CPython.Unlike traceback.print_exception(),thisfunctiontakesjustexceptionvalue
insteadofexceptiontype,exceptionvalue,andtracebackobject;fileargumentshould
bepositional;furtherargumentsarenotsupported.CPython-compatibletraceback
modulecanbefoundin micropython-lib.
Constants
sys.argv
Amutablelistofargumentsthecurrentprogramwasstartedwith.
sys.byteorder
Thebyteorderofthesystem("little"or"big").
sys.implementation
ObjectwithinformationaboutthecurrentPythonimplementation.ForMicroPython,ithas
followingattributes:
name-string"micropython"
version-tuple(major,minor,micro),e.g.(1,7,0)Thisobjectistherecommendedway
todistinguishMicroPythonfromotherPythonimplementations(notethatitstillmaynot
existintheveryminimalports).
DifferencetoCPython
5.3.3sys
353
CPythonmandatesmoreattributesforthisobject,buttheactualusefulbareminimumis
implementedinMicroPython.
sys.maxsize
Maximumvaluewhichanativeintegertypecanholdonthecurrentplatform,ormaximum
valuerepresentablebyMicroPythonintegertype,ifit’ssmallerthanplatformmaxvalue(that
isthecaseforMicroPythonportswithoutlongintsupport).
Thisattributeisusefulfordetecting"bitness"ofaplatform(32-bitvs64-bit,etc.).It’s
recommendedtonotcomparethisattributetosomevaluedirectly,butinsteadcountnumber
ofbitsinit:
bits=0
v=sys.maxsize
whilev:
bits+=1
v>>=1
ifbits>32:
#64-bit(ormore)platform
else:
#32-bit(orless)platform
#Notethaton32-bitplatform,valueofbitsmaybelessthan32
#(e.g.31)duetopeculiaritiesdescribedabove,souse">16",
#">32",">64"styleofcomparisons.
sys.modules
Dictionaryofloadedmodules.Onsomeports,itmaynotincludebuiltinmodules.
sys.path
Amutablelistofdirectoriestosearchforimportedmodules.
sys.platform
TheplatformthatMicroPythonisrunningon.ForOS/RTOSports,thisisusuallyanidentifier
oftheOS,e.g. linux.Forbaremetalports,itisanidentifierofaboard,e.g. pyboardfor
theoriginalMicroPythonreferenceboard.Itthuscanbeusedtodistinguishoneboardfrom
another.IfyouneedtocheckwhetheryourprogramrunsonMicroPython(vsotherPython
implementation),use sys.implementationinstead.
sys.stderr
Standarderrorstream.
sys.stdin
Standardinputstream.
5.3.3sys
354
sys.stdout
Standardoutputstream.
sys.version
Pythonlanguageversionthatthisimplementationconformsto,asastring.
sys.version_info
Pythonlanguageversionthatthisimplementationconformsto,asatupleofints.
5.3.3sys
355
uos–Basic"OperatingSystem"Services
The uosmodulecontainsfunctionsforfilesystemaccessand urandomfunction.
PortSpecifics
Thefilesystemhas /astherootdirectoryandtheavailablephysicaldrivesareaccessible
fromhere.Theyarecurrently:
/flash–theinternalflashfilesystem
/sd–theSDcard(ifitexists)
Functions
uos.uname()
Returninformationaboutthesystem,firmwarereleaseversion,andMicroPythoninterpreter
version.
uos.chdir(path)
Changecurrentdirectory.
uos.getcwd()
Getthecurrentdirectory.
uos.listdir([dir])
Withnoargument,listthecurrentdirectory.Otherwiselistthegivendirectory.
uos.mkdir(path)
Createanewdirectory.
uos.remove(path)
Removeafile.
uos.rmdir(path)
Removeadirectory.
5.3.4uos
356
uos.rename(old_path,new_path)
Renameafile.
uos.stat(path)
Getthestatusofafileordirectory.
Thereturnvalueisatuplewiththefollowing10values,inorder:
st_mode:protectionbits.
st_ino: inodenumber.(notimplemented,returns0)
st_dev:device.(notimplemented,returns0)
st_nlink:numberofhardlinks.(notimplemented,returns0)
st_uid:useridofowner.(notimplemented,returns0)
st_gid:groupidofowner.(notimplemented,returns0)
st_size:sizeoffileinbytes.
st_atime:timeofmostrecentaccess.
st_mtime:timeofmostrecentcontentmodification.
st_ctime:timeofmostrecentmetadatachange.
uos.getfree(path)
Returnsthefreespace(inKiB)inthedrivespecifiedbypath.
uos.sync()
Syncallfilesystems.
uos.urandom(n)
Returnabytesobjectwithnrandombytes.
uos.unlink(path)
Aliasforthe remove()method.
uos.mount(block_device,mount_point,*,readonly=False)
Mountsablockdevice(likeanSDobject)inthespecifiedmountpoint.Example:
os.mount(sd,'/sd')
uos.unmount(path)
Unmountsapreviouslymountedblockdevicefromthegivenpath.
5.3.4uos
357
uos.mkfs(block_deviceorpath)
Formatsthespecifiedpath,mustbeeither /flashor /sd.Ablockdevicecanalsobe
passedlikeanSDobjectbeforebeingmounted.
uos.dupterm(stream_object)
Duplicatetheterminal(theREPL)onthepassedstream-likeobject.Thegivenobjectmust
atleastimplementthe read()and write()methods.
Constants
uos.sep
Separationcharacterusedinpaths
5.3.4uos
358
array–ArraysofNumericData
SeePythonarrayformoreinformation.
Supportedformatcodes: b,B,h,H,i,I,l,L,q,Q,f,d(thelatter2dependingonthe
floating-pointsupport).
Classes
classarray.array(typecode[,iterable])
Createarraywithelementsofgiventype.Initialcontentsofthearrayaregivenbyan
iterable.Ifitisnotprovided,anemptyarrayiscreated.
array.append(val)
Appendnewelementtotheendofarray,growingit.
array.extend(iterable)
Appendnewelementsascontainedinaniterabletotheendofarray,growingit.
5.3.5array
359
cmath–MathematicalFunctionsfor
ComplexNumbers
The cmathmoduleprovidessomebasicmathematicalfunctionsforworkingwithcomplex
numbers.Floatingpointsupportrequiredforthismodule.
Functions
cmath.cos(z)
Returnthecosineof z.
cmath.exp(z)
Returntheexponentialof z.
cmath.log(z)
Returnthenaturallogarithmof z.Thebranchcutisalongthenegativerealaxis.
cmath.log10(z)
Returnthebase-10logarithmof z.Thebranchcutisalongthenegativerealaxis.
cmath.phase(z)
Returnsthephaseofthenumber z,intherange(-pi,+pi).
cmath.polar(z)
Returns,asatuple,thepolarformof z.
cmath.rect(r,phi)
Returnsthecomplexnumberwithmodulus randphasephi.
cmath.sin(z)
Returnthesineof z.
cmath.sqrt(z)
Returnthesquare-rootof z.
5.3.6cmath
360
Constants
cmath.e
Baseofthenaturallogarithm
cmath.pi
Theratioofacircle’scircumferencetoitsdiameter
5.3.6cmath
361
math–MathematicalFunctions
Themathmoduleprovidessomebasicmathematicalfunctionsforworkingwithfloating-point
numbers.Floatingpointsupportrequiredforthismodule.
Functions
math.acos(x)
Returntheinversecosineof x.
math.acosh(x)
Returntheinversehyperboliccosineof x.
math.asin(x)
Returntheinversesineof x.
math.asinh(x)
Returntheinversehyperbolicsineof x.
math.atan(x)
Returntheinversetangentof x.
math.atan2(y,x)
Returntheprincipalvalueoftheinversetangentof y/x.
math.atanh(x)
Returntheinversehyperbolictangentof x.
math.ceil(x)
Returnaninteger,beingxroundedtowardspositiveinfinity.
math.copysign(x,y)
Returnxwiththesignof y.
math.cos(x)
5.3.7math
362
Returnthecosineof x.
math.cosh(x)
Returnthehyperboliccosineof x.
math.degrees(x)
Returnradians xconvertedtodegrees.
math.erf(x)
Returntheerrorfunctionof x.
math.erfc(x)
Returnthecomplementaryerrorfunctionof x.
math.exp(x)
Returntheexponentialof x.
math.expm1(x)
Return exp(x)-1.
math.fabs(x)
Returntheabsolutevalueof x.
math.floor(x)
Returnaninteger,being xroundedtowardsnegativeinfinity.
math.fmod(x,y)
Returntheremainderof x/y.
math.frexp(x)
Decomposesafloating-pointnumberintoitsmantissaandexponent.Thereturnedvalueis
thetuple (m,e)suchthat x==m*2**eexactly.If x==0thenthefunctionreturns
(0.0,0),otherwisetherelation 0.5<=abs(m)<1holds.
math.gamma(x)
Returnthegammafunctionof x.
5.3.7math
363
math.isfinite(x)
Return Trueif xisfinite.
math.isinf(x)
Return Trueif xisinfinite.
math.isnan(x)
Return Trueif xisnot-a-number
math.ldexp(x,exp)
Return x*(2**exp).
math.lgamma(x)
Returnthenaturallogarithmofthegammafunctionof x.
math.log(x)
Returnthenaturallogarithmof x.
math.log10(x)
Returnthebase-10logarithmof x.
math.log2(x)
Returnthebase-2logarithmof x.
math.modf(x)
Returnatupleoftwofloats,beingthefractionalandintegralpartsof x.Bothreturnvalues
havethesamesignas x.
math.pow(x,y)
Returns xtothepowerof y.
math.radians(x)
Returndegrees xconvertedtoradians.
math.sin(x)
Returnthesineof x.
5.3.7math
364
math.sinh(x)
Returnthehyperbolicsineof x.
math.sqrt(x)
Returnthesquarerootof x.
math.tan(x)
Returnthetangentof x.
math.tanh(x)
Returnthehyperbolictangentof x.
math.trunc(x)
Returnaninteger,being xroundedtowards 0.
Constants
math.e
Baseofthenaturallogarithm
math.pi
Theratioofacircle’scircumferencetoitsdiameter
5.3.7math
365
gc–GarbageCollector
Functions
gc.enable()
Enableautomaticgarbagecollection.
gc.disable()
Disableautomaticgarbagecollection.Heapmemorycanstillbeallocated,andgarbage
collectioncanstillbeinitiatedmanuallyusinggc.collect().
gc.collect()
Runagarbagecollection.
gc.mem_alloc()
ReturnthenumberofbytesofheapRAMthatareallocated.
gc.mem_free()
ReturnthenumberofbytesofavailableheapRAM.
5.3.8gc
366
ubinascii–Binary/ASCIIConversions
Thismoduleimplementsconversionsbetweenbinarydataandvariousencodingsofitin
ASCIIform(inbothdirections).
Functions
ubinascii.hexlify(data[,sep])
Convertbinarydatatohexadecimalrepresentation.Returnsbytesstring.
DifferencetoCPython
Ifadditionalargument, sepissupplied,itisusedasaseparatorbetweenhexadecimal
values.
ubinascii.unhexlify(data)
Converthexadecimaldatatobinaryrepresentation.Returnsbytesstring.(i.e.inverseof
hexlify)
ubinascii.a2b_base64(data)
ConvertBase64-encodeddatatobinaryrepresentation.Returnsbytesstring.
ubinascii.b2a_base64(data)
EncodebinarydatainBase64format.Returnsstring.
5.3.9ubinascii
367
ujson–JSONEncodingandDecoding
ThismodulesallowstoconvertbetweenPythonobjectsandtheJSONdataformat.
Functions
ujson.dumps(obj)
Return objrepresentedasaJSONstring.
ujson.loads(str)
ParsetheJSON strandreturnanobject.Raises ValueErrorifthestringisnotcorrectly
formed.
ujson.load(fp)
Parsecontentsof fp(a .read()-supportingfile-likeobjectcontainingaJSONdocument).
Raises ValueErrorifthecontentisnotcorrectlyformed.
5.3.10ujson
368
ure–regularexpressions
Thismoduleimplementsregularexpressionoperations.Regularexpressionsyntax
supportedisasubsetofCPythonremodule(andactuallyisasubsetofPOSIXextended
regularexpressions).
Supportedoperatorsare:
.Matchanycharacter. []Matchsetofcharacters.Individualcharactersandrangesare
supported.
^
$
?
*
+
??
*?
+?
Countedrepetitions ({m,n}),moreadvancedassertions,namedgroups,etc.arenot
supported.
Functions
ure.compile(regex)
Compileregularexpression,return regexobject.
ure.match(regex,string)
Matchregexagainst string.Matchalwayshappensfromstartingpositioninastring.
ure.search(regex,string)
Searchregexinastring.Unlikematch,thiswillsearchstringforfirstpositionwhichmatches
regex(whichstillmaybe0ifregexisanchored).
ure.DEBUG
Flagvalue,displaydebuginformationaboutcompiledexpression.
Regexobjects
5.3.11ure
369
Compiledregularexpression.Instancesofthisclassarecreatedusing ure.compile().
regex.match(string)
regex.search(string)
regex.split(string,max_split=-1)
Matchobjects
Matchobjectsasreturnedby match()and search()methods.
match.group([index])
Onlynumericgroupsaresupported.
5.3.11ure
370
usocket–SocketModule
ThismoduleprovidesaccesstotheBSDsocketinterface.
SeecorrespondingCPythonmoduleforcomparison.
SocketAddressFormat(s)
Functionsbelowwhichexpectanetworkaddress,acceptitintheformatof (ipv4_address,
port),where ipv4_addressisastringwithdot-notationnumericIPv4address,e.g.
8.8.8.8,andportisintegerportnumberintherange1-65535.Notethedomainnamesare
notacceptedas ipv4_address,theyshouldberesolvedfirstusing socket.getaddrinfo().
Functions
socket.socket(socket.AF_INET,socket.SOCK_STREAM,socket.IPPROTO_TCP)
Createanewsocketusingthegivenaddressfamily,sockettypeandprotocolnumber.
socket.getaddrinfo(host,port)
Translatethehost/portargumentintoasequenceof5-tuplesthatcontainallthenecessary
argumentsforcreatingasocketconnectedtothatservice.Thelistof5-tupleshasfollowing
structure:
(family,type,proto,canonname,sockaddr)Thefollowingexampleshowshowtoconnect
toagivenurl:
s=socket.socket()
s.connect(socket.getaddrinfo('www.micropython.org',80)[0][-1])
Exceptions
socket.errorsocket.timeout
Constants
socket.AF_INETsocket.AF_LORA
Familytypes
5.3.12usocket
371
socket.SOCK_STREAMsocket.SOCK_DGRAMsocket.SOCK_RAW
Sockettypes
socket.IPPROTO_UDPsocket.IPPROTO_TCP
Socketprotocols
socket.SOL_SOCKETsocket.SOL_LORAsocket.SOL_SIGFOX
Socketoptionslayers
socket.SO_REUSEADDR
IPsocketoptions
socket.SO_CONFIRMEDsocket.SO_DR
LoRasocketoptions
socket.SO_RXsocket.SO_TX_REPEATsocket.SO_OOBsocket.SO_BIT
Sigfoxsocketoptions
classSocket
Methods
socket.close()
Markthesocketclosed.Oncethathappens,allfutureoperationsonthesocketobjectwill
fail.Theremoteendwillreceivenomoredata(afterqueueddataisflushed).
Socketsareautomaticallyclosedwhentheyaregarbage-collected,butitisrecommendedto
close()themexplicitly,ortouseawithstatementaroundthem.
socket.bind(address)
Bindthe socketto address.Thesocketmustnotalreadybebound.The address
parametermustbeatuplecontainingtheIPaddressandtheport.
InthecaseofLoRasockets,theaddressparameterissimplyanintegerwiththeport
number,forinstance: s.bind(1)
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372
socket.listen([backlog])
Enableaservertoacceptconnections.Ifbacklogisspecified,itmustbeatleast0(ifit’s
lower,itwillbesetto0);andspecifiesthenumberofunacceptedconnectionsthatthe
systemwillallowbeforerefusingnewconnections.Ifnotspecified,adefaultreasonable
valueischosen.
socket.accept()
Acceptaconnection.Thesocketmustbeboundtoanaddressandlisteningforconnections.
Thereturnvalueisapair (conn,address)where connisanewsocketobjectusableto
sendandreceivedataontheconnection,and addressistheaddressboundtothesocket
ontheotherendoftheconnection.
socket.connect(address)
Connecttoaremotesocketat address.
socket.send(bytes)
Senddatatothesocket.Thesocketmustbeconnectedtoaremotesocket.
socket.sendall(bytes)
Aliasof socket.send(bytes).
socket.recv(bufsize)
Receivedatafromthesocket.Thereturnvalueisabytesobjectrepresentingthedata
received.Themaximumamountofdatatobereceivedatonceisspecifiedby bufsize.
socket.sendto(bytes,address)
Senddatatothesocket.Thesocketshouldnotbeconnectedtoaremotesocket,sincethe
destinationsocketisspecifiedbyaddress.
socket.recvfrom(bufsize)
Receivedatafromthesocket.Thereturnvalueisapair (bytes,address)where bytesis
abytesobjectrepresentingthedatareceivedand addressistheaddressofthesocket
sendingthedata.
socket.setsockopt(level,optname,value)
5.3.12usocket
373
Setthevalueofthegivensocketoption.Theneededsymbolicconstantsaredefinedinthe
socketmodule( SO_*etc.).Thevaluecanbeanintegerorabytes-likeobjectrepresenting
abuffer.
socket.settimeout(value)
Setatimeoutonblockingsocketoperations.Thevalueargumentcanbeanonnegative
floatingpointnumberexpressingseconds,or None.Ifanon-zerovalueisgiven,
subsequentsocketoperationswillraiseatimeoutexceptionifthetimeoutperiodvaluehas
elapsedbeforetheoperationhascompleted.Ifzeroisgiven,thesocketisputinnon-
blockingmode.IfNoneisgiven,thesocketisputinblockingmode.
socket.setblocking(flag)
Setblockingornon-blockingmodeofthesocket:ifflagisfalse,thesocketissettonon-
blocking,elsetoblockingmode.
Thismethodisashorthandforcertain settimeout()calls:
sock.setblocking(True)isequivalenttosock.settimeout(None)
sock.setblocking(False)isequivalenttosock.settimeout(0.0)
socket.makefile(mode='rb')
Returnafileobjectassociatedwiththesocket.Theexactreturnedtypedependsonthe
argumentsgiventomakefile().Thesupportislimitedtobinarymodesonly( rband wb).
CPython’sarguments: encoding, errors,and newlinearenotsupported.
Thesocketmustbeinblockingmode;itcanhaveatimeout,butthefileobject’sinternal
buffermayendupinainconsistentstateifatimeoutoccurs.
DifferencetoCPython
Closingthefileobjectreturnedby makefile()WILLclosetheoriginalsocketaswell.
socket.read(size)
Readuptosizebytesfromthesocket.Returnabytesobject.If sizeisnotgiven,it
behavesjustlikesocket.readall(),seebelow.
socket.readall()
ReadalldataavailablefromthesocketuntilEOF.Thisfunctionwillnotreturnuntilthesocket
isclosed.
5.3.12usocket
374
socket.readinto(buf[,nbytes])
Readbytesintothe buf.If nbytesisspecifiedthenreadatmostthatmanybytes.
Otherwise,readatmost len(buf)bytes.
Returnvalue:numberofbytesreadandstoredinto buf.
socket.readline()
Readaline,endinginanewlinecharacter.
Returnvalue:thelineread.
socket.write(buf)
Writethebufferofbytestothesocket.
Returnvalue:numberofbyteswritten.
5.3.12usocket
375
select–WaitforEventsonaSetof
Streams
Thismoduleprovidesfunctionstowaitforeventsonstreams(selectstreamswhichare
readyforoperations).
Pyboardspecifics
Pollingisanefficientwayofwaitingforread/writeactivityonmultipleobjects.Current
objectsthatsupportpollingare:pyb.UART,pyb.USB_VCP.
Functions
select.poll()
Createaninstanceofthe Pollclass.
select.select(rlist,wlist,xlist[,timeout])
Waitforactivityonasetofobjects.
Thisfunctionisprovidedforcompatibilityandisnotefficient.Usageof Pollis
recommendedinstead.
classPoll
Methods
poll.register(obj[,eventmask])
Register objforpolling. eventmaskislogicalORof:
select.POLLIN-dataavailableforreading
select.POLLOUT-moredatacanbewritten
select.POLLERR-erroroccurred
select.POLLHUP-endofstream/connectionterminationdetected eventmaskdefaultsto
select.POLLIN|select.POLLOUT.
poll.unregister(obj)
Unregister objfrompolling.
5.3.13select
376
poll.modify(obj,eventmask)
Modifythe eventmaskfor obj.
poll.poll([timeout])
Waitforatleastoneoftheregisteredobjectstobecomeready.Returnslistof( obj, event,
...)tuples, eventelementspecifieswhicheventshappenedwithastreamandisa
combinationof select.POLL*constantsdescribedabove.Theremaybeotherelementsin
tuple,dependingonaplatformandversion,sodon’tassumethatitssizeis2.Incaseof
timeout,anemptylistisreturned.
Timeoutisinmilliseconds.
5.3.13select
377
utime–TimeFunctions
The utimemoduleprovidesfunctionsforgettingthecurrenttimeanddate,measuringtime
intervals,andfordelays.
TimeEpoch:Pycom’sESP32portusesstandardforPOSIXsystemsepochof 1970-01-01
00:00:00UTC.
Maintainingactualcalendardate/time
ThisrequiresaRealTimeClock(RTC).OnsystemswithunderlyingOS(includingsome
RTOS),anRTCmaybeimplicit.Settingandmaintainingactualcalendartimeis
responsibilityofOS/RTOSandisdoneoutsideofMicroPython,itjustusesOSAPItoquery
date/time.Onbaremetalportshoweversystemtimedependson machine.RTC()object.The
currentcalendartimemaybesetusing machine.RTC().datetime(tuple)function,and
maintainedbyfollowingmeans:
Byabackupbattery(whichmaybeanadditional,optionalcomponentforaparticular
board).
Usingnetworkedtimeprotocol(requiressetupbyaport/user).
Setmanuallybyauseroneachpower-up(manyboardsthenmaintainRTCtimeacross
hardresets,thoughsomemayrequiresettingitagaininsuchcase).
Ifactualcalendartimeisnotmaintainedwithasystem/MicroPythonRTC,functionsbelow
whichrequirereferencetocurrentabsolutetimemaybehavenotasexpected.
Functions
utime.gmtime([secs])
ConvertatimeexpressedinsecondssincetheEpoch(seeabove)intoan8-tuplewhich
contains: (year,month,mday,hour,minute,second,weekday,yearday)If secsisnot
providedor None,thenthecurrenttimefromtheRTCisused.
yearincludesthecentury(forexample2014).
monthis1-12
mdayis1-31
houris0-23
minuteis0-59
secondis0-59
weekdayis0-6forMon-Sun
5.3.14utime
378
yeardayis1-366
utime.localtime([secs])
Like gmtime()butconvertstolocaltime.If secsisnotprovidedor None,thecurrenttime
fromtheRTCisused.
utime.mktime()
Thisisinversefunctionof localtime.It’sargumentisafull8-tuplewhichexpressesatime
asper localtime.Itreturnsanintegerwhichisthenumberofsecondssince Jan1,2000.
utime.sleep(seconds)
Sleepforthegivennumberof seconds. secondscanbeafloating-pointnumbertosleep
forafractionalnumberofseconds.NotethatotherMicroPythonportsmaynotaccept
floating-pointargument,forcompatibilitywiththemuse sleep_ms()and sleep_us()
functions.
utime.sleep_ms(ms)
Delayforgivennumberofmilliseconds,shouldbepositiveor0.
utime.sleep_us(us)
Delayforgivennumberofmicroseconds,shouldbepositiveor0
utime.ticks_ms()
Returnsuptime,inmilliseconds.
utime.ticks_us()
Justlike ticks_msabove,butinmicroseconds.
utime.ticks_cpu()
Sameas ticks_us,butfaster.
utime.ticks_diff(old,new)
Measureperiodbetweenconsecutivecallsto ticks_ms(), ticks_us(),or ticks_cpu().
Thevaluereturnedbythesefunctionsmaywraparoundatanytime,sodirectlysubtracting
themisnotsupported. ticks_diff()shouldbeusedinstead."old"valueshouldactually
precede"new"valueintime,orresultisundefined.Thisfunctionshouldnotbeusedto
5.3.14utime
379
measurearbitrarilylongperiodsoftime(because ticks_*()functionswraparoundand
usuallywouldhaveshortperiod).Theexpectedusagepatternisimplementingeventpolling
withtimeout:
#WaitforGPIOpintobeasserted,butatmost500us
start=time.ticks_us()
whilepin.value()==0:
iftime.ticks_diff(start,time.ticks_us())>500:
raiseTimeoutError
utime.time()
Returnsthenumberofseconds,asaninteger,sincetheEpoch,assumingthatunderlying
RTCisset.IfanRTCisnotset,thisfunctionreturnsnumberofsecondssincepowerupor
reset).IfyouwanttodevelopportableMicroPythonapplication,youshouldnotrelyonthis
functiontoprovidehigherthansecondprecision.Ifyouneedhigherprecision,use
ticks_ms()and ticks_us()functions,ifyouneedcalendartime, localtime()withoutan
argumentisabetterchoice.
utime.timezone([secs])
Setorgetthetimezoneoffset,inseconds.If secsisnotprovided,itreturnsthecurrent
value.
InMicroPython, time.timezoneworkstheoppositewaytoPython.InPython,togetthe
localtime,youwrite local_time=utc-timezone,whileinMicroPythonitis local_time
=utc+timezone.
5.3.14utime
380
uhashlib–HashingAlgorithm
Thismoduleimplementsbinarydatahashingalgorithms.MD5andSHAaresupported.By
limitationsinthehardware,onlyoneactivehashingoperationissupportedatatime.
Constructors
classuhashlib.md5([data])
CreateaMD5hasherobjectandoptionallyfeeddataintoit.
classuhashlib.sha1([data])
CreateaSHA-1hasherobjectandoptionallyfeeddataintoit.
classuhashlib.sha224([data])
CreateaSHA-224hasherobjectandoptionallyfeeddataintoit.
classuhashlib.sha256([data])
CreateaSHA-256hasherobjectandoptionallyfeeddataintoit.
classuhashlib.sha384([data])
CreateaSHA-384hasherobjectandoptionallyfeeddataintoit.
classuhashlib.sha512([data])
CreateaSHA-512hasherobjectandoptionallyfeeddataintoit.
Methods
hash.update(data)
Feedmorebinarydataintohash.
hash.digest()
Returnhashforalldatapassedthroughhash,asabytesobject.Afterthismethodiscalled,
moredatacannotbefedintohashanylonger.
hash.hexdigest()
5.3.15uhashlib
381
ThismethodisNOTimplemented.Use ubinascii.hexlify(hash.digest())toachievea
similareffect.
5.3.15uhashlib
382
ussl–sslmodule
ThismoduleprovidesaccesstoTransportLayerSecurity(oftenknownas"SecureSockets
Layer")encryptionandpeerauthenticationfacilitiesfornetworksockets,bothclient-sideand
server-side.
Functions
ssl.wrap_socket(sock,keyfile=None,certfile=None,server_side=False,
cert_reqs=CERT_NONE,ca_certs=None)
Takesaninstance sockof socket.socket,andreturnsaninstanceofssl.SSLSocket,a
subtypeof socket.socket,whichwrapstheunderlyingsocketinanSSLcontext.Example:
importsocket
importssl
s=socket.socket()
ss=ssl.wrap_socket(s)
ss.connect(socket.getaddrinfo('www.google.com',443)[0][-1])
Certificatesmustbeusedinordertovalidatetheothersideoftheconnection,andalsoto
authenticateourselveswiththeotherend.Suchcertificatesmustbestoredasfilesusingthe
FTPserver,andtheymustbeplacedinspecificpathswithspecificnames.
Forinstance,toconnecttotheBlynkserversusingcertificates,takethefile ca.pemlocated
inthe blynkexamplesfolderandputitin /flash/cert/.Thendo:
importsocket
importssl
s=socket.socket()
ss=ssl.wrap_socket(s,cert_reqs=ssl.CERT_REQUIRED,ca_certs='/flash/cert/ca.pem')
ss.connect(socket.getaddrinfo('cloud.blynk.cc',8441)[0][-1])
SSLsocketsinheritallmethodsandfromthestandardsockets,seethe usocketmodule.
Exceptions
ssl.SSLError
Constants
5.3.16ussl
383
ssl.CERT_NONEssl.CERT_OPTIONALssl.CERT_REQUIRED
Supportedvaluesin cert_reqs
5.3.16ussl
384
ucrypto—Cryptography
Thismoduleprovidesnativesupportforcryptographicalgorithms.It’slooselybasedon
PyCrypto.
Classes
classAES-AdvancedEncryptionStandard
Methods
crypto.getrandbits(bits)
Returnsabytesobjectfilledwithrandombitsobtainedfromthehardwarerandomnumber
generator.
AccordingtotheESP32TechnicalReferenceManual,suchbits"...canbeusedasthe
basisforcryptographicaloperations"."Thesetruerandomnumbersaregeneratedbasedon
thenoiseintheWi-Fi/BTRFsystem.WhenWi-FiandBTaredisabled,therandomnumber
generatorwillgiveoutpseudo-randomnumbers."
Theparameter bitsisroundedupwardstothenearestmultipleof32bits.
Cryptographyisnotatrivialbusiness.Doingthingsthewrongwaycouldquicklyresultin
decreasedornosecurity.Pleasedocumentyourselfinthesubjectifyouaredepending
onencryptiontosecureimportantinformation.
5.3.17ucrypto
385
ustruct–PackandUnpackPrimitiveData
Types
SeePythonstructformoreinformation.
Supportedsize/byteorderprefixes: @,<,>,!.
Supportedformatcodes: b,B,h,H,i,I,l,L,q,Q,s,P,f,d(thelatter2depending
onthefloating-pointsupport).
Functions
ustruct.calcsize(fmt)
Returnthenumberofbytesneededtostorethegiven fmt.
ustruct.pack(fmt,v1,v2,...)
Packthevalues v1,v2,...accordingtotheformatstring fmt.Thereturnvalueisa
bytesobjectencodingthevalues.
ustruct.pack_into(fmt,buffer,offset,v1,v2,...)
Packthevalues v1,v2,...accordingtotheformatstring fmtintoabufferstartingat
offset. offsetmaybenegativetocountfromtheendofbuffer.
ustruct.unpack(fmt,data)
Unpackfromthe dataaccordingtotheformatstring fmt.Thereturnvalueisatupleofthe
unpackedvalues.
ustruct.unpack_from(fmt,data,offset=0)
Unpackfromthe datastartingat offsetaccordingtotheformatstring fmt. offsetmay
benegativetocountfromtheendofbuffer.Thereturnvalueisatupleoftheunpacked
values.
5.3.18ustruct
386
thread-Low-levelThreadingAPI
Thismoduleprovideslow-levelprimitivesforworkingwithmultiplethreads(alsocalledlight-
weightprocessesortasks)—multiplethreadsofcontrolsharingtheirglobaldataspace.For
synchronisation,simplelocks(alsocalledmutexesorbinarysemaphores)areprovided.
Whenathreadspecificerroroccursa RuntimeErrorexceptionisraised.
QuickUsageExample
import_thread
importtime
defth_func(delay,id):
whileTrue:
time.sleep(delay)
print('Runningthread%d'%id)
foriinrange(2):
_thread.start_new_thread(th_func,(i+1,i))
Functions
_thread.start_new_thread(function,args[,kwargs])
Startanewthreadandreturnitsidentifier.Thethreadexecutesthefunctionwiththe
argumentlistargs(whichmustbeatuple).Theoptional kwargsargumentspecifiesa
dictionaryofkeywordarguments.Whenthefunctionreturns,thethreadsilentlyexits.When
thefunctionterminateswithanunhandledexception,astacktraceisprintedandthenthe
threadexits(butotherthreadscontinuetorun).
_thread.exit()
Raisethe SystemExitexception.Whennotcaught,thiswillcausethethreadtoexitsilently.
_thread.allocate_lock()
Returnanewlockobject.Methodsoflocksaredescribedbelow.Thelockisinitially
unlocked.
_thread.get_ident()
5.3.19_thread
387
Returnthe threadidentifierofthecurrentthread.Thisisanonzerointeger.Itsvaluehas
nodirectmeaning;itisintendedasamagiccookietobeusede.g.toindexadictionaryof
thread-specificdata.Threadidentifiersmayberecycledwhenathreadexitsandanother
threadiscreated.
_thread.stack_size([size])
Returnthethreadstacksize(inbytes)usedwhencreatingnewthreads.Theoptionalsize
argumentspecifiesthestacksizetobeusedforsubsequentlycreatedthreads,andmustbe
0(useplatformorconfigureddefault)orapositiveintegervalueofatleast 4096(4KiB).
4KiBiscurrentlytheminimumsupportedstacksizevaluetoguaranteesufficientstackspace
fortheinterpreteritself.
Objects
_thread.LockType
Thisisthetypeoflockobjects.
classLock–usedforsynchronisationbetweenthreads
Methods
Lockobjectshavethefollowingmethods:
lock.acquire(waitflag=1,timeout=-1)
Withoutanyoptionalargument,thismethodacquiresthelockunconditionally,ifnecessary
waitinguntilitisreleasedbyanotherthread(onlyonethreadatatimecanacquirealock—
that’stheirreasonforexistence).
Iftheinteger waitflagargumentispresent,theactiondependsonitsvalue:ifitiszero,the
lockisonlyacquiredifitcanbeacquiredimmediatelywithoutwaiting,whileifitisnonzero,
thelockisacquiredunconditionallyasabove.
Ifthefloating-pointtimeoutargumentispresentandpositive,itspecifiesthemaximumwait
timeinsecondsbeforereturning.Anegativetimeoutargumentspecifiesanunboundedwait.
Youcannotspecifyatimeoutif waitflagiszero.
Thereturnvalueis Trueifthelockisacquiredsuccessfully, Falseifnot.
lock.release()
Releasesthelock.Thelockmusthavebeenacquiredearlier,butnotnecessarilybythe
samethread.
5.3.19_thread
388
lock.locked()
Returnthestatusofthelock: Trueifithasbeenacquiredbysomethread, Falseifnot.
Inadditiontothesemethods,lockobjectscanalsobeusedviathewithstatement,e.g.:
import_thread
a_lock=_thread.allocate_lock()
witha_lock:
print("a_lockislockedwhilethisexecutes")
5.3.19_thread
389
BuiltinFunctions
Allbuiltinfunctionsaredescribedhere.Theyarealsoavailableviabuiltinsmodule.
abs()
all()
any()
bin()
classbool
classbytearray
classbytes
callable()
chr()
classmethod()
compile()
5.3.20Builtin
390
classcomplex
classdict
dir()
divmod()
enumerate()
eval()
exec()
filter()
classfloat
classfrozenset
getattr()
globals()
5.3.20Builtin
391
hasattr()
hash()
hex()
id()
input()
classint
isinstance()
issubclass()
iter()
len()
classlist
locals()
map()
5.3.20Builtin
392
max()
classmemoryview
min()
next()
classobject
oct()
open()
ord()
pow()
print()
property()
range()
5.3.20Builtin
393
repr()
reversed()
round()
classset
setattr()
sorted()
staticmethod()
classstr
sum()
super()
classtuple
type()
zip()
5.3.20Builtin
394
5.3.20Builtin
395
ProductInfopages
Thefollowpagescontainallinformationrelatingtoeachproduct,forexamples:pinouts,
specsheets,relevantexamplesandnotes.
DevelopmentModules
WiPy2.0
WiPy3.0
SiPy
LoPy
LoPy4
GPy
FiPy
OEMmodules
W01
L01
L04
G01
L01/W01ReferenceBoard
UniversalReferenceBoard
ShieldsandExpansionboards
ExpansionBoard2.0
Pysense
Pytrack
DeepSleepShield
6.0Introduction
396
DevelopmentDevices
ThissectioncontainsallofthedatasheetsforthePycomDevelopmentDevices.This
includestheWiPy2.0and3.0,LoPy,LoPy4,SiPy,GPy,andFiPy.
6.1DevelopmentModules
397
WiPy2.0
Store:Discontinued,SeeWiPy3
GettingStartedClickHere
Pinout
ThepinoutoftheWiPy2isavailableasaPDFFile.
PleasenotethatthePINassignmentsforUART1(TX1/RX1),SPI(CLK,MOSI,MISO)
andI2C(SDA,SCL)aredefaultsandcanbechangedinSoftware.
Datasheet
6.1.1WiPy2.0
398
ThedatasheetoftheWiPy2isavailableasaPDFFile.
Notes
WiFi
Bydefault,uponboottheWiPy2willcreateaWiFiaccesspointwiththeSSID wipy-wlan-
XXXX,where XXXXisarandom4-digitnumber,andthepassword www.pycom.io.
Power
The VinpinontheWiPy2canbesuppliedwithavoltagerangingfrom 3.5vto 5.5v.
The 3.3vpinontheotherhandisoutputonly,andmustnotbeusedtofeedpowerintothe
WiPy2,otherwisetheon-boardregulatorwillbedamaged.
DeepSleep
DuetoacoupleissueswiththeWiPy2designthemoduledrawsmorecurrentthanitshould
whileindeepsleep.TheDC-DCswitchingregulatoralwaysstaysinhighperformancemode
whichisusedtoprovidethelowestpossibleoutputripplewhenthemodulesisinuse.Inthis
mode,itdrawsaquiescentcurrentof10mA.WhentheregulatorisputintoECOmode,the
quiescentcurrentgoesdownto10uA.Unfortunately,thepinusedtocontrolthismodeisout
oftheRTCdomain,andthereforenotusableduringdeepsleep.Thiscausestheregulatorto
alwaysstayinPWMmode,keepingitsquiescentcurrentat10mA.Alongsidethistheflash
chipdoesn'tenterpowerdownmodebecausetheCSpinisfloatingduringdeepsleep.This
causestheflashchiptoconsumearound2mAofcurrent.Toworkaroundthisissuea"deep
sleepshield"isavailablethatattachestothemoduleandallowspowertobecutofffromthe
device.Thedevicecanthenbere-enabledeitheronatimerorviapininterrupt.Withthe
deepsleepshieldthecurrentconsumptionduringdeepsleepisbetween7uAand10uA
dependingonthewakesourcesconfigured.
Tutorials
TutorialsonhowtotheWiPy2modulecanbefoundintheexamplessectionofthis
documentation.ThefollowingtutorialsmightbeofspecificinterestfortheWiPy2:
WiFiconnection
BLE
6.1.1WiPy2.0
399
6.1.1WiPy2.0
400
WiPy3.0
Store:BuyHere
GettingStartedClickHere
Pinout
ThepinoutoftheWiPy3isavailableasaPDFFile.
PleasenotethatthePINassignmentsforUART1(TX1/RX1),SPI(CLK,MOSI,MISO)
andI2C(SDA,SCL)aredefaultsandcanbechangedinSoftware.
6.1.2WiPy3.0
401
DifferencesfromWiPy2.0
Deepsleepcurrentdrawfixed,nowonly19.7µA
UpgradedRAMfrom512KBto4MB
UpgradedExternalFLASHfrom4MBto8MB
AntennaselectpinmovedfromGPIO16toGPIO21(P12)
Datasheet
ThedatasheetoftheWiPy3isavailableasaPDFFile.
Notes
WiFi
Bydefault,uponboottheWiPy3willcreateaWiFiaccesspointwiththeSSID wipy-wlan-
XXXX,where XXXXisarandom4-digitnumber,andthepassword www.pycom.io.
TheRFswitchthatselectsbetweentheon-boardandexternalantennaisconnectedto
P12,forthisreasonusing P12shouldbeavoidedunlessWiFiisdisabledinyour
application.
Power
The VinpinontheWiPy3canbesuppliedwithavoltagerangingfrom 3.5vto 5.5v.
The 3.3vpinontheotherhandisoutputonly,andmustnotbeusedtofeedpowerintothe
WiPy3,otherwisetheon-boardregulatorwillbedamaged.
Tutorials
TutorialsonhowtotheWiPy3modulecanbefoundintheexamplessectionofthis
documentation.ThefollowingtutorialsmightbeofspecificinterestfortheWiPy3:
WiFiconnection
BLE
6.1.2WiPy3.0
402
LoPy
Store:BuyHere
GettingStartedClickHere
Pinout
ThepinoutoftheLoPyisavailableasaPDFFile.
PleasenotethatthePINassignmentsforUART1(TX1/RX1),SPI(CLK,MOSI,MISO)
andI2C(SDA,SCL)aredefaultsandcanbechangedinSoftware.
Datasheet
6.1.3LoPy
403
ThedatasheetoftheLoPyisavailableasaPDFFile.
Notes
WiFi
Bydefault,uponboottheLoPywillcreateaWiFiaccesspointwiththeSSID lopy-wlan-
XXXX,where XXXXisarandom4-digitnumber,andthepassword www.pycom.io.
Power
The VinpinontheLoPycanbesuppliedwithavoltagerangingfrom 3.5vto 5.5v.The
3.3vpinontheotherhandisoutputonly,andmustnotbeusedtofeedpowerintothe
LoPy,otherwisetheon-boardregulatorwillbedamaged.
DeepSleep
DuetoacoupleissueswiththeLoPydesignthemoduledrawsmorecurrentthanitshould
whileindeepsleep.TheDC-DCswitchingregulatoralwaysstaysinhighperformancemode
whichisusedtoprovidethelowestpossibleoutputripplewhenthemodulesisinuse.Inthis
mode,itdrawsaquiescentcurrentof10mA.WhentheregulatorisputintoECOmode,the
quiescentcurrentgoesdownto10uA.Unfortunately,thepinusedtocontrolthismodeisout
oftheRTCdomain,andthereforenotusableduringdeepsleep.Thiscausestheregulatorto
alwaysstayinPWMmode,keepingitsquiescentcurrentat10mA.Alongsidethistheflash
chipdoesn'tenterpowerdownmodebecausetheCSpinisfloatingduringdeepsleep.This
causestheflashchiptoconsumearound2mAofcurrent.Toworkaroundthisissuea"deep
sleepshield"isavailablethatattachestothemoduleandallowspowertobecutofffromthe
device.Thedevicecanthenbere-enabledeitheronatimerorviapininterrupt.Withthe
deepsleepshieldthecurrentconsumptionduringdeepsleepisbetween7uAand10uA
dependingonthewakesourcesconfigured.
Tutorials
TutorialsonhowtotheLoPymodulecanbefoundintheexamplessectionofthis
documentation.ThefollowingtutorialsmightbeofspecificinterestfortheLoPy:
WiFiconnection
LoRaWANnode
6.1.3LoPy
404
LoRaWANnanogateway
BLE
6.1.3LoPy
405
LoPy4
Store:BuyHere
GettingStartedClickHere
Pinout
ThepinoutoftheLoPy4isavailableasaPDFFile.
PleasenotethatthePINassignmentsforUART1(TX1/RX1),SPI(CLK,MOSI,MISO)
andI2C(SDA,SCL)aredefaultsandcanbechangedinSoftware.
6.1.4LoPy4
406
Datasheet
ThedatasheetoftheLoPy4isavailableasaPDFFile.
Notes
WiFi
Bydefault,uponboottheLoPy4willcreateaWiFiaccesspointwiththeSSID lopy4-wlan-
XXXX,where XXXXisarandom4-digitnumber,andthepassword www.pycom.io.
TheRFswitchthatselectsbetweentheon-boardandexternalantennaisconnectedto
P12,forthisreasonusing P12shouldbeavoidedunlessWiFiisdisabledinyour
application.
Power
The VinpinontheLoPy4canbesuppliedwithavoltagerangingfrom 3.5vto 5.5v.The
3.3vpinontheotherhandisoutputonly,andmustnotbeusedtofeedpowerintothe
LoPy4,otherwisetheon-boardregulatorwillbedamaged.
Tutorials
TutorialsonhowtotheLoPy4modulecanbefoundintheexamplessectionofthis
documentation.ThefollowingtutorialsmightbeofspecificinterestfortheLoPy4:
WiFiconnection
LoRaWANnode
LoRaWANnanogateway
Sigfox
BLE
6.1.4LoPy4
407
SiPy
Store:BuyHere
GettingStartedClickHere
Pinout
ThepinoutoftheSiPyisavailableasaPDFFile.
PleasenotethatthePINassignmentsforUART1(TX1/RX1),SPI(CLK,MOSI,MISO)
andI2C(SDA,SCL)aredefaultsandcanbechangedinSoftware.
Datasheet
6.1.5SiPy
408
ThedatasheetoftheSiPyisavailableasaPDFFile.
Notes
WiFi
Bydefault,uponboottheSiPywillcreateaWiFiaccesspointwiththeSSID sipy-wlan-XXXX
,where XXXXisarandom4-digitnumber,andthepassword www.pycom.io.
Power
The VinpinontheSiPycanbesuppliedwithavoltagerangingfrom 3.5vto 5.5v.The
3.3vpinontheotherhandisoutputonly,andmustnotbeusedtofeedpowerintothe
SiPy,otherwisetheon-boardregulatorwillbedamaged.
DeepSleep
DuetoacoupleissueswiththeSiPydesignthemoduledrawsmorecurrentthanitshould
whileindeepsleep.TheDC-DCswitchingregulatoralwaysstaysinhighperformancemode
whichisusedtoprovidethelowestpossibleoutputripplewhenthemodulesisinuse.Inthis
mode,itdrawsaquiescentcurrentof10mA.WhentheregulatorisputintoECOmode,the
quiescentcurrentgoesdownto10uA.Unfortunately,thepinusedtocontrolthismodeisout
oftheRTCdomain,andthereforenotusableduringdeepsleep.Thiscausestheregulatorto
alwaysstayinPWMmode,keepingitsquiescentcurrentat10mA.Alongsidethistheflash
chipdoesn'tenterpowerdownmodebecausetheCSpinisfloatingduringdeepsleep.This
causestheflashchiptoconsumearound2mAofcurrent.Toworkaroundthisissuea"deep
sleepshield"isavailablethatattachestothemoduleandallowspowertobecutofffromthe
device.Thedevicecanthenbere-enabledeitheronatimerorviapininterrupt.Withthe
deepsleepshieldthecurrentconsumptionduringdeepsleepisbetween7uAand10uA
dependingonthewakesourcesconfigured.
Tutorials
TutorialsonhowtotheSiPymodulecanbefoundintheexamplessectionofthis
documentation.ThefollowingtutorialsmightbeofspecificinterestfortheSiPy:
WiFiconnection
Sigfox
6.1.5SiPy
409
BLE
6.1.5SiPy
410
GPy
Store:BuyHere
GettingStartedClickHere
Pinout
ThepinoutoftheGPyisavailableasaPDFFile.
PleasenotethatthePINassignmentsforUART1(TX1/RX1),SPI(CLK,MOSI,MISO)
andI2C(SDA,SCL)aredefaultsandcanbechangedinSoftware.
Datasheet
6.1.6GPy
411
ThedatasheetoftheGPyisavailableasaPDFFile.
Notes
WiFi
Bydefault,uponboottheGPywillcreateaWiFiaccesspointwiththeSSID gpy-wlan-XXXX,
where XXXXisarandom4-digitnumber,andthepassword www.pycom.io.
TheRFswitchthatselectsbetweentheon-boardandexternalantennaisconnectedto
P12,forthisreasonusing P12shouldbeavoidedunlessWiFiisdisabledinyour
application.
Power
The VinpinontheGPycanbesuppliedwithavoltagerangingfrom 3.5vto 5.5v.The
3.3vpinontheotherhandisoutputonly,andmustnotbeusedtofeedpowerintothe
GPy,otherwisetheon-boardregulatorwillbedamaged.
ATCommands
TheATcommandsfortheSequansMonarchmodemontheGPyareavailableinaPDFfile.
Tutorials
TutorialsonhowtotheGPymodulecanbefoundintheexamplessectionofthis
documentation.ThefollowingtutorialsmightbeofspecificinterestfortheGPy:
WiFiconnection
LTECAT-M1
NB-IoT
BLE
6.1.6GPy
412
FiPy
Store:BuyHere
GettingStartedClickHere
Pinout
ThepinoutoftheFiPyisavailableasaPDFFile.
PleasenotethatthePINassignmentsforUART1(TX1/RX1),SPI(CLK,MOSI,MISO)
andI2C(SDA,SCL)aredefaultsandcanbechangedinSoftware.
Datasheet
6.1.7FiPy
413
ThedatasheetoftheFiPyisavailableasaPDFFile.
Notes
WiFi
Bydefault,uponboottheFiPywillcreateaWiFiaccesspointwiththeSSID fipy-wlan-XXXX
,where XXXXisarandom4-digitnumber,andthepassword www.pycom.io.
TheRFswitchthatselectsbetweentheon-boardandexternalantennaisconnectedto
P12,forthisreasonusing P12shouldbeavoidedunlessWiFiisdisabledinyour
application.
Power
The VinpinontheFiPycanbesuppliedwithavoltagerangingfrom 3.5vto 5.5v.The
3.3vpinontheotherhandisoutputonly,andmustnotbeusedtofeedpowerintothe
FiPy,otherwisetheon-boardregulatorwillbedamaged.
ATCommands
TheATcommandsfortheSequansMonarchmodemontheFiPyareavailableinaPDFfile.
Tutorials
TutorialsonhowtotheFiPymodulecanbefoundintheexamplessectionofthis
documentation.ThefollowingtutorialsmightbeofspecificinterestfortheFiPy:
WiFiconnection
LoRaWANnode
LoRaWANnanogateway
Sigfox
LTECAT-M1
NB-IoT
BLE
6.1.7FiPy
414
6.1.7FiPy
415
OEMDevices
ThissectioncontainsallofthedatasheetsforthePycomOEMDevices.Thisincludesthe
W01,L01,L04,andG01.
6.2OEMModules
416
W01
Pinout
ThepinoutoftheW01isavailableasaPDFFile.
Specsheets
ThespecsheetoftheW01isavailableasaPDFFile.
6.2.1W01
417
Drawings
ThedrawingsfortheW01isavailableasaPDFFile.
PleasenotethatthePINassignmentsforUART1(TX1/RX1),SPI(CLK,MOSI,MISO)and
I2C(SDA,SCL)aredefaultsandcanbechangedinSoftware.
Tutorials
TutorialsonhowtotheW01modulecanbefoundintheexamplessectionofthis
documentation.ThefollowingtutorialsmightbeofspecificinterestfortheW01:
WiFiconnection
BLE
6.2.1W01
418
L01
Pinout
ThepinoutoftheL01isavailableasaPDFFile.
Specsheets
ThespecsheetoftheL01isavailableasaPDFFile.
6.2.2L01
419
Drawings
ThedrawingsfortheL01isavailableasaPDFFile.
PleasenotethatthePINassignmentsforUART1(TX1/RX1),SPI(CLK,MOSI,MISO)and
I2C(SDA,SCL)aredefaultsandcanbechangedinSoftware.
Tutorials
TutorialsonhowtotheL01modulecanbefoundintheexamplessectionofthis
documentation.ThefollowingtutorialsmightbeofspecificinterestfortheL01:
WiFiconnection
LoRaWANnode
LoRaWANnanogateway
BLE
6.2.2L01
420
L04
Pinout
ThepinoutoftheL04isavailableasaPDFFile.
Specsheets
ThespecsheetoftheL04isavailableasaPDFFile.
6.2.3L04
421
Drawings
ThedrawingsfortheL04isavailableasaPDFFile.
PleasenotethatthePINassignmentsforUART1(TX1/RX1),SPI(CLK,MOSI,MISO)and
I2C(SDA,SCL)aredefaultsandcanbechangedinSoftware.
Tutorials
TutorialsonhowtotheL04modulecanbefoundintheexamplessectionofthis
documentation.ThefollowingtutorialsmightbeofspecificinterestfortheL04:
WiFiconnection
LoRaWANnode
LoRaWANnanogateway
Sigfox
BLE
6.2.3L04
422
G01
Pinout
ThepinoutoftheG01isavailableasaPDFFile.
Specsheets
ThespecsheetoftheG01isavailableasaPDFFile.
6.2.4G01
423
Drawings
ThedrawingsfortheG01isavailableasaPDFFile.
PleasenotethatthePINassignmentsforUART1(TX1/RX1),SPI(CLK,MOSI,MISO)and
I2C(SDA,SCL)aredefaultsandcanbechangedinSoftware.
ATCommands
TheATcommandsfortheSequansMonarchmodemontheG01areavailableinaPDFfile.
Tutorials
TutorialsonhowtotheG01modulecanbefoundintheexamplessectionofthis
documentation.ThefollowingtutorialsmightbeofspecificinterestfortheG01:
WiFiconnection
LTECAT-M1
NB-IoT
BLE
6.2.4G01
424
L01referencedesign
TheL01OEMreferenceboardisareferencedesignsuitableL01aswellasW01makingit
possibletohaveasinglePCBdesignthatcanaccommodatebothOEMmodules.
IfyourequireareferenceboardfortheL04orG01,thisdesignisnotsuitableasitdoes
notfeatureaSIMslotorthedoubleantennaconnection.FortheG01orL04pleaseuse
theUniversalOEMBaseboardReference
Features
SuitsbothL01orW01OEMModules
U.FLconnectorfortheL01'sLoRaoutput.
On-board2.4GHzantennaforWiFiandBluetooth,withtheabilitytoswitchtoaexternal
antennaviaaU.FLconnector.
WS2812BRGBLED
3.5-5.5InputswitchmodeDC-DCregulatorwithlowcurrentdrawduringdeepsleep
Resetbutton
Layout
ThelayoutoftheL01baseboardreferenceisavailableasaPDFFile.
6.2.5L01OEMBaseboardReference
425
Schematic
TheschematicoftheL01baseboardreferenceisavailableasaPDFFile.
AltiumProjectandGerberFiles
TheAltiumProjectandGerberfilesarealsoavailableasaZIPFile.
6.2.5L01OEMBaseboardReference
426
6.2.5L01OEMBaseboardReference
427
OEMBaseboardReferenceDesignFiles
TheuniversalOEMreferenceboardisareferencedesignsuitableW01,L01,L04andG01
OEMmodules,makingitpossibletohaveasinglePCBdesignthatcanaccommodateall
ourOEMmodules.
IfyourequireareferenceboardfortheG01,onlythisdesignissuitable.TheL01
referenceboarddoesnotcontainthenecessarySIMslot.
Features
SuitsallOEMmodules(L01,L04,W01,G01)
On-board2.4GHzantennaforWiFiandBluetooth,withtheabilitytoswitchtoaexternal
antennaviaaU.FLconnector.
3U.FLconnectorsforalltheoutputsavailableontheOEMmodules
WS2812BRGBLED
3.5-5.5InputswitchmodeDC-DCregulatorwithlowcurrentdrawduringdeepsleep
Resetbutton
Layout
ThelayoutoftheOEMbaseboardreferenceisavailableasaPDFFile.
6.2.6UniversalOEMBaseboardReference
428
Schematic
TheschematicoftheOEMbaseboardreferenceisavailableasaPDFFile.
AltiumProjectandGerberFiles
TheAltiumProjectandGerberfilesarealsoavailableasaZIPFile.
6.2.6UniversalOEMBaseboardReference
429
6.2.6UniversalOEMBaseboardReference
430
ExpansionBoardsandShields
ThissectioncontainsallofthedatasheetsforthePycomExpansionBoardsandShields.
ThisincludestheExpansionBoard,Pytrack,PysenseandDeepSleepShield.
6.3ExpansionBoardsandShields
431
ExpansionBoard3.0
Pinout
ThepinoutoftheExpansionBoardisavailableasaPDFFile.
Begentlewhenplugging/unpluggingfromtheUSBconnector.WhilsttheUSBconnector
issolderedandisrelativelystrong,ifitbreaksoffitcanbeverydifficulttofix.
BatteryCharger
6.3.1ExpansionBoard3.0
432
TheExpansionBoardfeaturesasinglecellLi-Ion/Li-Pocharger.Whentheboardisbeing
poweredviathemicroUSBconnector,theExpansionBoardwillchargethebattery(if
connected).Whenthe CHGjumperispresentthebatterywillbechargedat 450mA.Ifthis
valueistoohighforyourapplication,removingthejumperlowersthechargecurrentto
100mA.
Specsheets
ThespecsheetoftheExpansionBoardisavailableasaPDFFile.
Differencesbetweenv2.0andv3.0
TheFTDIchipasbeenreplacedwithacustomprogrammedPIClikeonthe
Pysense/Pytrack/Pyscanboards.Thisallowsourfirmwareupdatetooltoautomatically
putthemoduleintobootloadermode.
Addeda"Safeboot"buttontoentersafebooteasier.Thisbuttonconnects P12to
3.3vandifpressedandheldwhiletheresetbuttonispressedonaPycommodule,
themodulewillentersafeboot.
6.3.1ExpansionBoard3.0
433
Pytrack
Pinout
ThepinoutofthePytrackisavailableasaPDFFile.
BatteryCharger
TheboardfeaturesasinglecellLi-Ion/Li-Pocharger.Whentheboardisbeingpoweredvia
themicroUSBconnector,itwillchargethebattery(ifconnected).
Specsheets
6.3.2Pytrack
434
ThespecsheetofthePytrackisavailableasaPDFFile.
6.3.2Pytrack
435
Pysense
Pinout
ThepinoutofthePysenseisavailableasaPDFFile.
BatteryCharger
TheboardfeaturesasinglecellLi-Ion/Li-Pocharger.Whentheboardisbeingpoweredvia
themicroUSBconnector,itwillchargethebattery(ifconnected).
Specsheets
6.3.3Pysense
436
ThespecsheetofthePysenseisavailableasaPDFFile.
6.3.3Pysense
437
Pyscan
PyscanLibraries
PyscanlibrariestousetheRFID/NFCreaderarelocatedhere:
https://github.com/pycom/pycom-libraries/tree/master/pyscanTheaccelerometerlibraryis
here:https://github.com/pycom/pycom-libraries/blob/master/pytrack/lib/LIS2HH12.py
Forthetimebeing,werecommendtouploadthe MFRC630.mpyfileviaFTPduetocurrent
limitationsofPymakrthatwillbefixedshortly.
Librariesfortherestofthecomponentswillbeaddedsoon.
Pyscancomponents:
Accelerometer:STLIS2HH12
Ambientlightsensor:Lite-onLTR-329ALS-01
RFID/NFCreader:NXPMFRC63002HN,151
Driver
TheWindows7driverforPyscanislocatedin:
https://docs.pycom.io/chapter/pytrackpysense/installation/drivers.htmlForotherOperating
Systemsthere'snodriverrequired.
Pinout
ThepinoutofthePyscanisavailableasaPDFFile.
6.3.4Pyscan
438
BatteryCharger
TheboardfeaturesasinglecellLi-Ion/Li-Pocharger.Whentheboardisbeingpoweredvia
themicroUSBconnector,itwillchargethebattery(ifconnected).
Specsheets
ThespecsheetofthePyscanisavailableasaPDFFile.
6.3.4Pyscan
439
ExpansionBoard2.0
Pinout
ThepinoutoftheExpansionBoardisavailableasaPDFFile.
6.3.5ExpansionBoard2.0
440
Begentlewhenplugging/unpluggingfromtheUSBconnector.WhilsttheUSBconnector
issolderedandisrelativelystrong,ifitbreaksoffitcanbeverydifficulttofix.
BatteryCharger
TheExpansionBoardfeaturesasinglecellLi-Ion/Li-Pocharger.Whentheboardisbeing
poweredviathemicroUSBconnector,theExpansionBoardwillchargethebattery(if
connected).Whenthe CHGjumperispresentthebatterywillbechargedat 450mA.Ifthis
valueistoohighforyourapplication,removingthejumperlowersthechargecurrentto
100mA.
Specsheets
ThespecsheetoftheExpansionBoardisavailableasaPDFFile.
6.3.5ExpansionBoard2.0
441
DeepSleepShield
TheschematicoftheDeepSleepShieldisavailableasaPDFFile.
Pinout
ThepinoutoftheDeepSleepShieldisavailableasaPDFFile.
TocorrectlyconnectaWiPy2.0,LoPyorSiPytotheDeepSleepShield,alignthewhite
triangleontheShieldwiththeLEDofthePycomDevice.OncethePycomDeviceis
seatedontotheDeepSleepShield,thiscanthenbeconnectedtotheExpansionBoard.
6.3.6DeepSleepShield
442
6.3.6DeepSleepShield
443
DeepSleepAPI
ThischapterdescribesthelibrarywhichcontrolstheDeepSleepShield.Thisincludesthe
controlsforexternalinterruptsandtimersetupofthedeepsleepfunctionality.
Tousethislibrary,pleaseuploadtheassociatedDeepSleepLibraryto /libonthetarget
Pycomdevice.
QuickExample
fromdeepsleepimportDeepSleep
importdeepsleep
ds=DeepSleep()
#getthewakereasonandthevalueofthepinsduringwakeup
wake_s=ds.get_wake_status()
print(wake_s)
ifwake_s['wake']==deepsleep.PIN_WAKE:
print("Pinwakeup")
elifwake_s['wake']==deepsleep.TIMER_WAKE:
print("Timerwakeup")
else:#deepsleep.POWER_ON_WAKE:
print("PowerONreset")
ds.enable_pullups('P17')#canalsodods.enable_pullups(['P17','P18'])
ds.enable_wake_on_fall('P17')#canalsodods.enable_wake_on_fall(['P17','P18'])
ds.go_to_sleep(60)#gotosleepfor60seconds
DeepSleep
TheDeepSleepShieldallowsforwakingupviaausertriggerandalsoviaanexternal
interrupt(i.e.Accelerometer,Button).
Constructors
classDeepSleep()
CreatesaDeepSleepobject,thatwillcontroltheboard'ssleepfeatures.Forexample;
ds=DeepSleep()
6.3.6.1DeepSleepAPI
444
Methods
deepsleep.enable_auto_poweroff()
Thismethodallowsforacriticalbatteryvoltagetobeset.Forexample,iftheexternalpower
source(e.g.LiPoCell)fallsbelow 3.3V,turnoffthePycomdevice.Thisisintendedto
protectthehardwarefromundervoltage.
deepsleep.enable_pullups(pins)
Thismethodallowsforpull-uppinstobeenabled.Forexample,ifanexternaltriggeroccurs,
wakethePycomdevicefromDeepSleep. pinsmaybepassedintothemethodasalist,
i.e. ['P17','P18'].
deepsleep.disable_pullups(pins)
Thismethodallowsforpull-uppinstobedisabled.Forexample,ifanexternaltriggeroccurs,
wakethePycomdevicefromDeepSleep. pinsmaybepassedintothemethodasalist,
i.e. ['P17','P18'].
deepsleep.enable_wake_on_raise(pins)
Thismethodallowsforpull-uppinstotriggeronarisingvoltage.Forexample,ifanexternal
risingvoltagetriggersoccurs,wakethePycomdevicefromDeepSleep.pinsmaybe
passedintothemethodasalist,i.e. ['P17','P18'].
deepsleep.disable_wake_on_raise(pins)
Thismethodallowsfordisablingpull-uppinsthattriggeronarisingvoltage. pinsmaybe
passedintothemethodasalist,i.e. ['P17','P18'].
deepsleep.enable_wake_on_fall(pins)
Thismethodallowsforpull-uppinstotriggeronafallingvoltage.Forexample,ifanexternal
fallingvoltagetriggersoccurs,wakethePycomdevicefromDeepSleep. pinsmaybe
passedintothemethodasalist,i.e. ['P17','P18'].
deepsleep.disable_wake_on_fall(pins)
Thismethodallowsfordisablingpull-uppinsthattriggeronafallingvoltage. pinsmaybe
passedintothemethodasalist,i.e. ['P17','P18'].
deepsleep.get_wake_status()
Thismethodreturnsthestatusofthepinsatwakeupfromdeepsleep.Themethodreturnsa
dictwiththestatesof wake, P10, P17, P18.
6.3.6.1DeepSleepAPI
445
deepsleep.set_min_voltage_limit(value)
Thismethodrelatestothe enable_auto_poweroffmethodandallowstheusertospecifythe
minimumpoweroffvoltageasavalue.
deepsleep.go_to_sleep(seconds)
Thismethodsendstheboardintodeepsleepforaperiodof secondsoruntilanexternal
interrupthastriggered(see set_pullups).
deepsleep.hw_reset()
ThismethodresetsthePICcontrollerandresetsittothestateprevioustothepins/min-
voltagebeingset.
Pleasenotethatmorefunctionalityisbeingaddedweeklytotheselibraries.Ifarequired
featureisnotavailable,feelfreetocontributewithapullrequestatthePycomLibraries
GitHubrepository.
6.3.6.1DeepSleepAPI
446
Notes
Poweringwithanexternalpowersource
Thedevicescanbepoweredbyabatteryorotherexternalpowersource.
Besuretoconnectthepositiveleadofthepowersupplyto VIN,andgroundto GND.
Whenpoweringvia VIN:
Theinputvoltagemustbebetween 3.4Vand 5.5V.
PleaseDONOTpowertheboardviathe 3.3Vpinasthismaydamagethedevice.
ONLYusethe VINpinforpoweringPycomdevices.
ThebatteryconnectorfortheExpansionBoardisaJSTPHR-2variant.TheExpansion
Boardexposesthemaleconnectorandanexternalbatteryshoulduseafemaleadapterin
ordertoconnectandpowertheexpansionboard.Thepolarityofthebatteryshouldbe
checkedbeforebeingpluggedintotheexpansionboard,thecablesmayrequireswapping.
The GPIOpinsofthemodulesareNOT5Vtolerant,connectingthemtovoltages
higherthan 3.3Vmightcauseirreparabledamagetothedevice.
Staticelectricitycandamagecomponentsonthedeviceandmaydestroythem.Ifthere
isalotofstaticelectricityinthearea(e.g.dryandcoldclimates),takeextracarenotto
shockthedevice.IfthedevicecameinaESDbag(Silverpackaging),thebestwayto
storeandcarrythedeviceisinsidethisbagasitwillbeprotectedagainststatic
discharges.
6.4Notes
447
DevelopmentModulesDatasheets
7.1.1WiPy2.0
7.1.2WiPy3.0
7.1.3LoPy
7.1.4LoPy4
7.1.5SiPy
7.1.6GPy
7.1.7FiPy
7.1DevelopmentModules
448
OEMModuleDatasheets
7.2.1W01
7.2.2L01
7.2.3L04
7.2.4G01
7.2OEMModules
449
ExpansionBoardandShieldDatasheets
7.3.1ExpansionBoard3.0
7.3.2Pytrack
7.3.3Pysense
7.3.4ExpansionBoard2.0
7.3ExpansionBoardsandShields
450
WhatisPybytes?
PybytesisanIoTEcosystemthatempowersyoubygrantingfullcontrolofallyourPycom
devices.
WithPybytesyouhavecontroloveryourdevice'sdatastreamandmore:
Visualisesensorsdataaccordingtoyourinterestsusingourcustomisabledashboard;
Checkthestatusofyourentirefleet;
Keeptrackofyourassetswithourgeolocationfeature;
Distributefirmwareupdatesonascalableapproach.
Inanutshell,PybytesisanenvironmentdesignedtooptimiseyourIoTapplicationsusing
Pycomboards.
WhatPybytesoffersyou?
DataVisualisation:Pybytesdashboardiscustomisable,allowingyoutofreelysetupkey
performanceindicatorsandtimeseriesdatafromallyoursensors.
Intelligentnotifications:Keeptrackofyourdevice'sstatus,batterylevel,datastreaming
andmeasurementswithpre-definedalarms.ReceivenotificationsviaemailorSMS.
Terminal:Executecommandstogatheraccurateinformationfromyourdevicesusing
Pybytesterminalshell.
Firmwareupdatesovertheair:Upgradeordowngradefirmwareversionswithour
exclusivefirmwareupdate.
Trackyourassetsposition:GoogleMapsAPIempowersyourviewoveryourdevice's
geolocation.
Let'sgetstarted!
GettingstartedwithPybytes
ConnectyourPycommoduletoPybytes
8.1Introduction
451
Visualisedatafromyourdevice
8.1Introduction
452
CreateyourPybytesaccount
FollowthesestepstocreateaPybytesaccount:
Step1:Gototheregistrationpage
1. Gotothislink.
2. Enteryourfullname,emailaddressandapasswordtoyouraccount.
3. Confirmtheverificationmessagesenttoyouremailaddress.
4. Clickonthelinkandcompleteyourlogin.
GoInvent!
Nowit'stimetoexplorePybytes.YoucanstartbyconnectingyourPycomboardtoPybytes.
Checkhere!
8.2GettingStarted
453
Addadevicetopybytes
Inthissection,wewillexplaintoyouhowtoaddadevicetoPybytes
Step1:Adddevicewizard
InPybytes,goto DevicesPage:
1. Clickon AddDevice.
2. Selectyourdevice(e.g.,WiPy,LoPy,SiPy,etc.);
8.3AddadevicetoPybytes
454
3. Selectyourshield(e.g.,PySense,PyTrack,PyScanorother);
4. Selectyournetworkoption;
8.3AddadevicetoPybytes
455
5. Enterauniquenameandthenetworkcredentials(SSIDandpassword)foryourdevice;
Step2:ConnectyourdevicetoPybytes
Attheendofthe"AddDevice"wizard,Pybyteswillgiveyoutwooptionsforyoutoconnect
yourdevicetoPybytes:
8.3AddadevicetoPybytes
456
SelecthowyouwouldliketoconnectyourdevicetoPybytes:
1. CONNECTYOURDEVICEQUICKLY(RECOMMENDED)
2. CONNECTYOURDEVICEBYFLASHINGPYBYTESLIBRARY
Fromfirmware1.16.xonwardsallPycomdevicescomewithPybyteslibrarybuild-in
/frozenfolder.Thatmeansthatyoucanchoosebetweenaddingyourdevicequickly
withthefirmwareupdateroryoucanflashPybyteslibrarymanually.
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ConnectingadevicetoPybytesquicklyby
usingtheFirmwareUpdater
Inthissection,weexplaintoyouhowtoconnectyourdevicetoPybytesquicklyusingthe
FirmwareUpdater.
IncaseyouwanttoextendPybyteslibraryyoucanflashPybyteslibrarymanually.Click
hereformoreinformation.
Step1:Downloadthefirmwareupdater
Atthelaststepofthe"AddDevice"process:
1. Downloadthefirmwareupdaterforyouroperatingsystem;
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2. Copythedevicetoken.
Step2:Firmwareupdater
InstalltheFirmwareupdateronyourcomputer.
1. Startthe Firmwareupdater;
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2. Selectyourdeviceserialport(Makesureyourdeviceisconnectedtoyourcomputer);
3. Marktheoptions"Eraseflashfilesystem"and"ForceupdatePybytesregistration";
4. PasteyourdevicetokenfromPybytes;
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5. Thefirmwareupdaterwillupdatethedevice'sfirmware.
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Nextstep:Setupyourdevice's
dashboard!
Nowit'stimetodisplaydatafromyourdeviceintoPybytesdashboard.Youcancheckmore
aboutithere!
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ConnectingadevicetoPybytesby
flashingPybyteslibrarymanually
Inthissection,wewillexplaintoyouhowtoconnectyourdevicetoPybytesbyflashing
Pybyteslibrarymanually.
Fromfirmware1.16.xonwardsallPycomdevicescomewithPybyteslibrarybuild-in
/frozenfolder.Thatmeansthatyoucanaddyourdevicequicklywithouttheneedof
flashingPybyteslibrarymanually.Clickhereformoreinformation.
Step1:DownloadyourPybytesLibrary
Atthelaststepofthe"AddDevice"process:
1.Clickondownload*Pybyteslibrary*
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YoucanalsodownloadPybyteslibraryatthedevice'ssettingspage:
1. NavigatetoyourdeviceinPybytes;
2. Onyourdevice'spageclickonsettingstab;
3. ClickonthebuttonDownloadatPybyteslibrary;
Step2.FlashyourdevicewithPymakr
Incaseyouhaven'tinstalledPymakrplugin,followtheseinstructions.
1. ConnectyourdevicetoyourcomputerwithUSBcable.
2. ExtractdownloadPybyteslibraryandopenextractedfolderwithAtom.
3. Getyourdeviceserialport:inPymakrpluginclickonMore>getserialports
4. Pasteyourdevice'sserialportto pymakr.conffile:
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{
"address":"PASTE_YOUR_SERIAL_PORT_HERE",
"username":"micro",
"password":"python",
"sync_folder":"flash"
}
5. Checkoutyour flash/pybytes_config.jsonfile.Itwillbepre-filledwithyourinformation
fromPybytesLikedeviceTokenorWiFicredentials.Youcanchangee.g.yourWiFy
passwordhere.
6. Putyourdeviceinsafebootmode.
7. UploadcodetoyourdevicebyclickingonUploadbuttoninPymakr.AfterallPybytes
libraryfilesareuploadedtodevice,devicewillrestartandwillconnecttoPybytes.
Pybyteslibraryiswrittento /flashfolderandwilltakeprecedenceoverbuildin
firmwarelibrariesin /frozenfolder.
Nextstep:Setupyourdevice's
dashboard!
Nowit'stimetodisplaydatafromyourdeviceintoPybytesdashboard.Youcancheckmore
aboutithere!
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Visualisedatafromyourdevice.
Inthissection,wewillexplaintoyouhowtocreatewidgetsfordatavisualisationandsetup
yourdevice'sdashboardonPybytes.
WeassumethatyoualreadyhaveyourdeviceconnectedtoPybytes.Incaseyou
haven't,checkhowtoaddyourdevicehere.Afteryourdonewiththat,youcanproceed
tothenextexample.
Step1:Setupyourapplication(main.py)
Thefirststepistohaveanapplicationrunningonyourdevice.Theapplicationinthis
examplesendsdatafromavectorevery10secondstoPybytes.
1. Openthe main.pyfileonPymakr;
2. Insertthefollowingcodeonyour main.py;
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##Importwhatisnecessarytocreateathread
import_thread
fromtimeimportsleep
##Incrementindexusedtoscaneachpointfromvectorsensors_data
definc(index,vector):
ifindex<len(vector)-1:
returnindex+1
else:
return0
##Defineyourthread'sbehaviour,hereit'saloopsendingsensorsdataevery10sec
onds
defsend_env_data():
idx=0
sensors_data=[0,-0.2,-0.5,-0.7,-0.8,-0.9,-0.9,-0.9,-0.8,-0.6,-0.4,-0.2
,0,0.3,0.5,0.7,0.8,0.9,0.9,0.9,0.8,0.6,0.4,0.1]
while(pybytes):
pybytes.send_virtual_pin_value(False,1,sensors_data[idx])
idx=inc(idx,sensors_data)
sleep(10)
##Startyourthread
_thread.start_new_thread(send_env_data,())
1. Uploadthecodeintoyourdevice.NowyourdeviceissendingdatatoPybytes.
Inthiscode,we'recallingthefunction pybytes.send_virtual_pin_value(persistent,
pin,value))tocommunicatewithPybytes.ThisfunctionispartofthePybytes
library,andithasthreearguments: persistent, pinand value.
persistentdenotesinformationthatisinfrequentlyaccessedandnotlikelyto
bemodified;
pinrepresentswhichvirtualpinisreceivingdata;
valueisthevaluebeingattributedtothatparticularpin.
Step2:Addasignalfromyourdevice
GotoPybytes.
1. On Devicespageselectadevice;
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2. Onyourdevice'spageclickon Datatab.
3. Clickonthe DefineNewSignalbutton.
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4. Definethenewsignalbyenteringanumber,aname,adatatypeandaunit.Finally,
clickonthebutton Define.
5. Yoursignalwasadded!
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ThenameandunitarelabelsusedtoidentifyyoursignalinsidePybytes(Inthis
examplewedefined Sinwaveasthenameofthesignaland Radastheunit).
Thesignalnumberhastomatchthepinnumberthatyoudefinedon
pybytes.send_virtual_pin_valuefunctioncall,insideyour main.pycode(Inthis
examplewedefined pin=1);
Thedatatypealsohastomatchthevariableusedasargumenton
pybytes.send_virtual_pin_valuefunctioncall,insideyour main.pycode(Inthis
exampleourvariableisafloatingnumber;thereforewedefinedasa Float32).
Step3:Addawidgetforthesignal
1. Clickonthesignalcard.
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2. Clickonthebutton Createanewdisplay.
3. Selectthetypeofvisualisation(e.g.BarchartorLinechart).
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4. Youcanadjusttheparametersofyourwidgetat Settings.After,clickonthebutton
Create.
5. Yourwidgetwascreated.Now,addyourwidgettoyourdevice'sdashboard.Clickonthe
button Editonyourwidget.
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6. Markthecheckbox DisplayonDashboardat Settings.Finally,clickonthebutton
Save.
7. Clickonthetab Dashboard.Yourwidgetwassuccessfullyaddedthere!
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Step4:Organiseyourdashboard
1. Clickonthebutton Organise.Nowthedashboard'sgridwillentertheeditmodeand
allowyoutoresizeandrepositionitswidgets.
2. Resizeawidgetbyclickingonthetriangleiconatthebottomrightcornerofthewidget
anddragthecursoroverthegrid.After,clickonthebutton Savetosavethisaction.
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3. Changethewidget'spositionbydrag-and-droppingitoverthegrid.After,clickonthe
button Savetosavethisaction.
Done!
Nowyou'velearnedhowtosetupyourdevice'sdashboardtodisplaydata.Also,youcan
addmorewidgetstootherpinsofyourdevice.
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8.4Visualisedatafromyourdevice
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DocumentationNotes
ThePycomdocumentationaimstobestraightforwardandtoadheretotypicalPython
documentationtoallowforeaseofunderstanding.However,theremaybesomeunusual
featuresforthosenotusedtoPythondocumentationorthatarenewtotheMicroPython
Language.Thissectionofthedocumentationaimstoprovideclarityforanyofthedesign
specificsthatmightbeconfusingforthosenewtoPythonandthisstyleofdocumentation.
9.1Introduction
477
DocumentationSyntax
ThePycomdocumentationfollowsstandardPythonLibraryformatusingthepopularSphinx
Docstool.Therearesomenotablepointsregardingthesyntaxofclasses,methodsand
constants.Pleaseseethenotesbelowandfamiliariseyourselfwiththespecificdetails
beforereviewingthedocumentation.
KeywordArguments
KeywordArgumentsrefertotheargumentsthatarepassedintoaconstructor(upon
referencingaclassobject).WhenpassingvaluesintoaMicroPythonconstructoritisnot
alwaysrequiredtospecifythenameoftheargumentandinsteadrelyontheorderofthe
argumentspassedastodescribewhattheyreferto.Intheexamplebelow,itcanbeseen
thattheargument modeispassedintothe i2c.init()methodwithoutspecifyinganame.
Thevaluesofthearguments(asseenintheexamples/docs)refertothedefaultvaluesthat
arepassedintotheconstructorifnothingisprovided.
i2c.init(mode,*,baudrate=100000,pins=(SDA,SCL))
Anexampleofhowthismethodmightbecalled:
i2c.init(I2C.MASTER,pins=('P12','P11'))
Itcanbeseenthatavaluefor baudratewasnotpassedintothemethodandthus
MicroPythonwillassumeadefaultvalueof 100000.Alsothefirstargument modewasnot
specifiedbyname,astheconstructordoesnotrequireit,denotedbythelackofan =
symbolintheconstructordocumentation.
PassingArgumentsintoaMethod
Itisimportanttonotethattherearecertainclassmethodsthatcanonlyaccepta keyword
forcertainargumentsaswellassomethatonlyaccepta value.Thisisintentionalby
designbutisnotalwaysapparenttotheusercallingspecificmethods.Thedifferences
betweenthetwoareoutlinedbelow,withexamplesreferencingwheredifferencesmight
applyandwhattobeawareof.
Keyword
9.2Syntax
478
Anastrik *inamethoddescription(inthedocs),denotesthatthefollowingarguments
requireakeyword,i.e. pin='P16'intheexamplebelow.
adc.channel(*,pin,attn=ADC.ATTN_0DB)
frommachineimportADC
adc=ADC()#createanADCobject
apin=adc.channel(pin='P16')#createananalogpinonP16
pinisarequiredargumentandthemethod channelwillnotexecuteunlessitispassed
aswithakeyword.
Anotherexampleshowshowthe PWMclass, pwm.channel()requiresakeywordargument
for pinbutdoesnotfor id.
frommachineimportPWM
pwm=PWM(0,frequency=5000)
pwm_c=pwm.channel(0,pin='P12')#nokeywordargumentrequiresforid(0)butisreq
uiredforpin(pin='P12')
Value
Thedocumentationmayrefertoamethodthattakesanargumentlistedbynamebutdoes
allowforakeywordtobepassed.Forexample,the pycomclasscontainsamethod
rgbled.Thisliststhatthemethodacceptsavaluefor color,howeverthismaynotbe
specifiedby keyword,only value.Thisisintentionalasthe valuebeingpassedisthe
onlyargumentvalidforthismethod
pycom.rgbled(color)
Iftheargumentispassedintothemethodwithakeyword,itwillreturnanerrorstating
TypeError:functiondoesnottakekeywordarguments.
importpycom
pycom.rgbled(color=0xFF0000)#Incorrect
pycom.rgbled(0xFF0000)#Correct
Anotherexampleofamethodthatonlyacceptsvalueinput.Inthiscase,the RTC.init()
methodrequireavalue( tuple)inputforthe datetime.Itwillnotacceptakeyword.
rtc.init(datetime)
9.2Syntax
479
frommachineimportRTC
rtc=RTC()
rtc.init(datetime=(2014,5,1,4,13,0,0,0))#Incorrect
rtc.init((2014,5,1,4,13,0,0,0))#Correct
Constants
The constantssectionofalibrarywithinthedocsreferstospecificvaluesfromthatlibrary’s
class.Thesemightbeusedwhenconstructinganobjectfromthatclassorwhenutilisinga
methodfromwithinthatclass.Thesearegenerallylistedbythelibrarynamefollowedbythe
specificvalue.Seetheexamplebelow:
I2C.MASTER()
Beawarethatyoucanonlyreferencetheseconstantsuponimportingandconstructing
aobjectfromalibrary.
9.2Syntax
480
REPLvsScripts
Usersofthisdocumentationshouldbeawarethatexamplesgiveninthedocsareunderthe
expectationthattheyarebeingexecutedusingtheMicroPythonREPL.Thismeansthat
whencertainfunctionsarecalled,theiroutputmaynotnecessarilybeprintedtotheconsole
iftheyarerunfromascript.WhenusingtheREPLmanyclasses/functionsautomatically
produceaprintedoutputdisplayingthereturnvalueofthefunctiontotheconsole.Thecode
snippetbelowdemonstratessomeexamplesofclasses/functionsthatmightdisplaythis
behaviour.
BasicArithmetic
1+1#REPLwillprintout'2'toconsole
1+1#Scriptwillnotreturnanythingtheconsole
print(1+1)#BoththeREPLandascriptwillreturn'2'totheconsole
CallingMethods
importubinascii
ubinascii.hexlify(b'12345')#REPLwillprintout"b'3132333435'"totheconsole
ubinascii.hexlify(b'12345')#Scriptwillnotreturnanytheconsole
Inordertousethesefunctionsthatdonotprintoutanyvalues,youwillneedtoeitherwrap
themina print()statementorassignthemtovariablesandcallthemlaterwhenyouwish
tousethem.
Forexample:
#immediatelyprinttoconsolewhenusingascript
print(1+1)
#orsavevariabletoforlater
value=1+1
#dosomethinghere...
print(value)
9.3REPLvsScripts
481
FirmwareDowngrade
Thefirmwareupgradetoolusuallyupdatesyourdevicetothelatestavailablefirmware
version.Ifyourequiretodowngradeyourdevicetoapreviousfirmwaretherearetwo
methodstoachievethis.
IfyouareusinganExpansionBoard1.0or2.0,youwillneedtohaveajumper
connectedbetween G23and GNDtouseeitherprocedurebelow.Youwillalsoneedto
presstheresetbuttonbeforebeginning.
Youcanobtainpreviousfirmwareversionshere:
WiPy
LoPy
SiPy
GPy
FiPy
LoPy4
Note:Priortoversion 1.16.0.b1thefirmwareformoduleswithLoRafunctionalitywas
frequencyspecific.From 1.16.0.b1andonward,thefirmwareisregionagnosticandthis
caneitherbesetprogramaticallyorviatheconfigblock(seehere).
GUI
Asofversion 1.12.0.b0ofthefirmwareupdatetool,youcannowprovidea .taror
.tar.gzarchiveofthefirmwareyouwishtouploadtotheboard.
Whenyoustarttheupdatetoolyouwillseethefollowingscreen:
10.1FirmwareDowngrade
482
Whenyoutickthe Flashfromlocalfileoption,anaddressbarwillappear.Clickthe ...
buttonandlocatethe .tar(.gz)filewiththefirmwareyouwishtoflashtoyourdevice.
Fromthispointtheupdaterwillbehavejustlikearegularupdatebutusingthelocalfile
insteadofdownloadingthelatest.
Commandline
YoucanalsousetheCLIversionoftheupdatetooltodowngradeyourdevice.Willneedto
geta .taror .tar.gzarchiveofthefirmwareyouwishtouploadtotheboard.Thenrun
thefollowingcommands:
$pycom-fwtool-cli-v-pPORTflash-t/path/to/firmware/archive.tar.gz
10.1FirmwareDowngrade
483
CommandLineUpdateUtility
Windows
AfterinstallingtheWindowsversionoftheupdatertool,theCLItool pycom-fwtool-cli.exe
canbefoundhere:
32-BitWindows: C:\ProgramFiles\Pycom\PycomFirmwareUpdate\
64-BitWindows: C:\ProgramFiles(x86)\Pycom\PycomFirmwareUpdate\
macOS
InordertogetaccesstotheCLItoolonmacOS,youwillneedtorightclickontheMac
versionoftheupdatertoolandclick ShowPackageContents,thennavigateto
Contents/Resources,hereyouwillfindthe pycom-fwtool-cli.
Linux
IntheUbuntu14.04LTS(andnewer)versionoftheupdatertool, pycom-fwtool-cliis
installedin /usr/local/bin.IntheGenericLinuxpackage,thetoolisextractedintofolder
./pyupgrade
Usage
10.2CLIUpdater
484
usage:pycom-fwtool-cli[-h][-v][-d][-q][-pPORT][-sSPEED][-c][-x]
[--ftdi][--pic][-r]
{list,chip_id,wmac,smac,sigfox,exit,flash,copy,write,write_rem
ote,wifi,pybytes,cb,nvs,ota,lpwan,erase_fs,erase_all}
...
UpdateyourPycomdevicewiththespecifiedfirmwareimagefileFormore
detailspleaseseehttps://docs.pycom.io/chapter/advance/cli.html
positionalarguments:
{list,chip_id,wmac,smac,sigfox,exit,flash,copy,write,write_remote,wifi,pybytes,cb,nv
s,ota,lpwan,erase_fs,erase_all}
listGetlistofavailableCOMports
chip_idShowESP32chip_id
wmacShowWiFiMAC
smacShowLPWANMAC
sigfoxShowsigfoxdetails
exitExitfirmwareupdatemode
flashWritefirmwareimagetoflash
copyRead/Writeflashmemorypartition
writeWritetoflashmemory
wifiGet/SetdefaultWIFIparameters
pybytesRead/Writepybytesconfiguration
cbRead/Writeconfigblock
nvsRead/Writenonvolatilestorage
otaRead/Writeotablock
lpwanGet/SetLPWANparameters[EU868US915AS923AU915]
erase_fsEraseflashfilesystemarea
erase_allEraseentireflash!
optionalarguments:
-h,--helpshowthishelpmessageandexit
-v,--verboseshowverboseoutputfromesptool
-d,--debugshowdebugginoutputfromfwtool
-q,--quietsuppresssuccessmessages
-pPORT,--portPORTtheserialporttouse
-sSPEED,--speedSPEED
baudrate
-c,--continuationcontinuepreviousconnection
-x,--noexitdonotexitfirmwareupdatemode
--ftdiforcerunninginftdimode
--picforcerunninginpicmode
-r,--resetuseEspressifresetmode
HowtousetheParameters
TheCLItoolusesacombinationofglobalandcommandspecificparameters.Theorder
ofparametersisimportanttoavoidambiguity.
10.2CLIUpdater
485
pycom-fwtool-cli[globalparameters][command][commandparameters]
While pycom-fwtool-cli-hshowshelpforglobalparametersandalistofavailable
commands,commandspecificparameterscanbeviewedusing pycom-fwtool-cli
[command]-h
Theparameter -r,--resethasbeenaddedasacourtesyforusersof3rdparty
ESP32products.ThisfunctionalityisnotsupportedbytheExpansionBoard2.0and
maycausethistooltocrashorhangincertaincircumstances.
GlobalParameters
`-h/--help`:showsabovehelp(youcanalsogetdetailedhelpforeachsub-comma
nd
`-v/--verbose`:showverboseoutputfromesptool.
`-d/--debug`:showdebugoutputfromfwtool.
`-q/--quiet`:suppressmostoutput,usedforscripting
`-p/--port`:specifiestheserialporttobeused.Canalsobesetvia**environ
mentvariableESPPORT**
`-s/--speed`:specifiestheserialspeedtobeused.Canalsobesetvia**enviro
nmentvariableESPBAUD**
`-c/--continuation`:continuepreviousconnectioninFTDImode.Thisallowsrunning
multiplecommandssequentiallywithouthavingtoresetthemodule.Thisoptionisign
oredinPICmodeasthemodulecanberesetviatheserialconnection.
`-x/--noexit`:ThiswillpreventthePICfromleavingfirmwareupdatemode.
`--ftdi`:ThiswillforcetheCLIupdatertoruninFTDImode.
`--pic`:ThiswillforcetheCLIupdatertoruninPICmode.
`-r,--reset`:ThiswillforcetheCLIupdatertouseEspressif'sworkaroundtosw
itchintoFirmwareupdatemode.Thisresetmethodisintendedfor3rdpartyhardwareo
nlyandisnotsupportedbytheExpansionBoard2.0
Commands
list
Getlistofavailableserialportsports.
usage:pycom-fwtool-clilist[-h]
optionalarguments:
-h,--helpshowthishelpmessageandexit
Example:OnmacOS:
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$pycom-fwtool-clilist
/dev/cu.usbmodemPy343431[Pytrack][USBVID:PID=04D8:F013SER=Py343434LOCATION=20-2]
/dev/cu.Bluetooth-Incoming-Port[n/a][n/a]
OnWindows:
COM6[Pytrack][USBVID:PID=04D8:F013SER=Py343434LOCATION=20-2]
Thisistheonlycommandthatdoesnotrequireanyadditionalparameters.
Allothercommandsrequirethattheserialportisspecifiedeitherthroughthe -p/
--portoptionorthroughenvironmentvariable ESPPORTYoucanoptionallyspecify
thespeedeitherthrough -s/ --speedorviaenvironmentvariable ESPBAUD.The
defaultspeedis 921600.ThemaximumspeedforreadoperationsonPICbased
expansionboards&shieldsis 230400.Thespeedwillbereducedautomaticallyif
necessary.
SpecialnoteforExpansionBoard2.0
Youwillneedtohaveajumperwireconnectedbetween G23and GNDtouseanyof
thecommandsbelow.Youwillalsoneedtopresstheresetbuttoneitherbefore
runningeachcommandoratleastbeforerunningthefirstcommand.Toavoidhavingto
presstheresetbuttonagainaftereachcommand,youcanusethe -c/ --
continuationoption.ThefirstcommandconnectingtothedeviceMUSTNOTusethe -
c/ --continuationoption.Thisistomakesureaprogramcalled _stub_isuploaded
ontothedevice.This _stub_cannotbeuploadedmorethanonce,soyouneedtotell
theclitoolthatthe _stub_isalreadyrunning,whichisdonethroughusingthe -c/--
continuationoption.
chip_id
ShowstheuniqueIDoftheESP32ontheconnectedmodule.
usage:pycom-fwtool-cli-pPORTexit[-h]
optionalarguments:
-h,--helpshowthishelpmessageandexit
wmac
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ShowstheWiFiMACoftheconnectedmodule.
usage:pycom-fwtool-cli-pPORTwmac[-h]
optionalarguments:
-h,--helpshowthishelpmessageandexit
smac
ShowstheLPWANMACoftheconnectedmodule.
usage:pycom-fwtool-cli-pPORTsmac[-h]
optionalarguments:
-h,--helpshowthishelpmessageandexit
sigfox
Showsigfoxdetails
usage:pycom-fwtool-cli-pPORTsigfox[-h]
optionalarguments:
-h,--helpshowthishelpmessageandexit
exit
IfaPysense/Pytrack/Expansion3haspreviouslybeenleftinfirmwareupdatemodebyusing
the -xoption,thiscommandcanbeusedtoexitthefirmwareupdatemode.
usage:pycom-fwtool-cli-pPORTexit[-h]
optionalarguments:
-h,--helpshowthishelpmessageandexit
flash
Writesfirmwareimagetoflash,mustbeasa .tar(.gz)fileasprovidedbyPycom.These
filescanbefoundonGitHub.
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usage:pycom-fwtool-cli-pPORTflash[-h][-tTAR]
optionalarguments:
-h,--helpshowthishelpmessageandexit
-tTAR,--tarTARperformtheupgradefromatar[.gz]file
copy
Read/Writeflashmemorypartitionfrom/tolocalfile
usage:pycom-fwtool-cli-pPORT[-h][-pPARTITION][-fFILE][-r][-b]
optionalarguments:
-h,--helpshowthishelpmessageandexit
-pPARTITION,--partitionPARTITION
Thepartitiontoread/write(all,fs,nvs,factory,
secureboot,bootloader,partitions,otadata,fs1,
ota_0,config)
-fFILE,--fileFILEnameofthebinaryfile(default:<wmac>-<part>.bin)
-r,--restorerestorepartitionfrombinaryfile
-b,--backupbackuppartitiontobinaryfile(default)
write
Writetoaspecificlocationinflashmemory.
usage:pycom-fwtool-cli-pPORTwrite[-h][-aADDRESS][--contentsCONTENTS]
optionalarguments:
-h,--helpshowthishelpmessageandexit
-aADDRESS,--addressADDRESS
addresstowriteto
--contentsCONTENTScontentsofthememorytowrite(base64)
wifi
Get/SetdefaultWiFiparameters.
usage:pycom-fwtool-cliwifi[-h][--ssidSSID][--pwdPWD][--wob[WOB]]
optionalarguments:
-h,--helpshowthishelpmessageandexit
--ssidSSIDSetWifiSSID
--pwdPWDSetWifiPWD
--wob[WOB]SetWifionboot
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pybytes
Read/Writepybytesconfiguration.
usage:pycom-fwtool-clipybytes[-h][--tokenTOKEN][--mqttMQTT][--uidUID]
[--nwprefsNWPREFS][--extraprefsEXTRAPREFS]
optionalarguments:
-h,--helpshowthishelpmessageandexit
--tokenTOKENSetDeviceToken
--mqttMQTTSetmqttServiceAddress
--uidUIDSetuserId
--nwprefsNWPREFSSetnetworkpreferences
--extraprefsEXTRAPREFS
Setextrapreferences
Note:Thelocal pybytes_config.jsonfileisoverwrittenwhenmakinganymodifications
usingthiscommand(requiresPybytesfirmware 1.17.5.b6orhigherandFirmware
updater 1.14.3).
cb
Read/Writeconfigblock(LPMAC,SigfoxPAC&ID,etc.).Youcanfindthestructureofthis
blockhere.
usage:pycom-fwtool-cli-pPORTcb[-h][-fFILE][-b][-r]
optionalarguments:
-h,--helpshowthishelpmessageandexit
-fFILE,--fileFILEnameofthebackupfile
-b,--backupbackupcbpartitiontofile
-r,--restorerestorecbpartitionfromfile
Ifneither -bor -risprovided,thecommandwilldefaulttobackup.Ifnofilenameis
provided, <WMAC>.cbisused.
Tobackupyourconfigblock: $pycom-fwtool-cli-pPORTcb
Torestoreyourconfigblock: $pycom-fwtool-cli-pPORTcb-r-fbackup.cb
nvs
Read/Writenon-volatilestorage.
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usage:pycom-fwtool-cli-pPORTnvs[-h][-fFILE][-b][-r]
optionalarguments:
-h,--helpshowthishelpmessageandexit
-fFILE,--fileFILEnameofthebackupfile
-b,--backupbackupcbpartitiontofile
-r,--restorerestorecbpartitionfromfile
Ifneither -bor -risprovided,thecommandwilldefaulttobackup.Ifnofilenameis
provided, <WMAC>.nvsisused.
TobackupyourNVS: $pycom-fwtool-cli-pPORTnvs
TorestoreyourNVS: $pycom-fwtool-cli-pPORTnvs-r-fbackup.nvs
ota
Read/Writeotablock,thiscontainsdatarelatingtoOTAupdatessuchasthehashofthe
OTAfirmware.
usage:pycom-fwtool-cliota[-h][-fFILE][-b][-r]
optionalarguments:
-h,--helpshowthishelpmessageandexit
-fFILE,--fileFILEnameofthebackupfile
-b,--backupbackupcbpartitiontofile
-r,--restorerestorecbpartitionfromfile
Ifneither -bnor -risprovided,thecommandwilldefaulttobackup.Ifnofilenameis
provided, <WMAC>.otaisused.
TobackupyourOTAblock: $pycom-fwtool-cli-pPORTota
TorestoreyourOTAblock: $pycom-fwtool-cli-pPORTota-r-fbackup.ota
lpwan
Get/SetLPWANparameterssavedtonon-volatilestorage.Pleaseseehereformoredetails.
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usage:pycom-fwtool-cli-pPORTlpwan[-h][--regionREGION]
optionalarguments:
-h,--helpshowthishelpmessageandexit
--regionREGIONSetdefaultLORAregion
--erase_regionErasedefaultLORAregion
--lora_regionOutputonlyLORAregion
erase_fs
Eraseflashfilesystemarea.Thisisusefulifsomecoderunningonthedeviceispreventing
accesstotheREPL.
usage:pycom-fwtool-cli-pPORTerase_fs[-h]
optionalarguments:
-h,--helpshowthishelpmessageandexit
erase_all
Eraseentireflash,onlyusethisifyouaresureyouknowwhatyouaredoing.Thiswill
removeyourdeviceslpwanmacaddressesetc.
usage:pycom-fwtool-clierase_all[-h]
optionalarguments:
-h,--helpshowthishelpmessageandexit
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StepsforusingSecureBootandFlash
Encryption
Summary
Inordertoencryptyourfirmware,youwillneedtobuilditfromsource.Ourfirmwaresource
codecanbefoundhere,alongwithinstructionsonhowtobuildit.Belowyouwillfind
specificinstructionsonhowgeneratekeys,buildandflashencryptedfirmware.
1. Obtainkeys(forSecureBootandFlashEncryption)
2. Flashkeysandparametersin efuses
3. Compilebootloaderandapplicationwith makeSECURE=on
4. Flash:bootloader-digestataddress 0x0andencrypted;alltheothers(partitionsand
application)encrypted,too.
Prerequisites
Firstlyyouwillneedtosetupthetoolchainanddownloadthesourcecode.detailed
instructionsonhowtoachievethiscanbefoundhere.Onceyouhavecompletethis,youwill
needtoopenaterminalinthe esp32folderofthefirmwaresourcecoderepo.
NextyouwillneedkeysforFlashEncryptionandSecureBoot;theycanbegenerated
randomlywiththefollowingcommands:
python$IDF_PATH/components/esptool_py/esptool/espsecure.pygenerate_flash_encrypt
ion_keyflash_encryption_key.bin
python$IDF_PATH/components/esptool_py/esptool/espsecure.pygenerate_signing_keys
ecure_boot_signing_key.pem
TheSecureBootkey secure_boot_signing_key.pemhastobetransformedinto secure-
bootloader-key.bin,tobeburntintoefuses.Thiscanbedonein2ways:
python$IDF_PATH/components/esptool_py/esptool/espsecure.pyextract_public_key--k
eyfilesecure_boot_signing_key.pemsignature_verification_key.bin
or,asanartifactofthemakebuildprocess,onthesamedirectorylevelasMakefile
makeBOARD=GPYSECURE=onTARGET=boot
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Toflashthekeys( flash_encryption_key.binand secure-bootloader-key.bin)intothe
efuses(writeandreadprotected)runthefollowingcommands(ignoringthelinesthatstart
with #):
Note:Irreversibleoperations
#BurningEncryptionKey
python$IDF_PATH/components/esptool_py/esptool/espefuse.py--port/dev/ttyUSB0bur
n_keyflash_encryptionflash_encryption_key.bin
#BurningSecureBootKey
python$IDF_PATH/components/esptool_py/esptool/espefuse.py--port/dev/ttyUSB0bur
n_keysecure_bootsecure-bootloader-key.bin
#EnablingFlashEncryptionmechanism
python$IDF_PATH/components/esptool_py/esptool/espefuse.py--port/dev/ttyUSB0bur
n_efuseFLASH_CRYPT_CNT
#ConfiguringFlashEncryptiontousealladdressbitstogetherwithEncryptionke
y(maxvalue0x0F)
python$IDF_PATH/components/esptool_py/esptool/espefuse.py--port/dev/ttyUSB0bur
n_efuseFLASH_CRYPT_CONFIG0x0F
#EnablingSecureBootmechanism
python$IDF_PATH/components/esptool_py/esptool/espefuse.py--port/dev/ttyUSB0bur
n_efuseABS_DONE_0
Ifthekeysarenotwritteninefuse,beforeflashingthebootloader,thenrandomkeys
willbegeneratedbytheESP32,theycanneverbereadnorre-written,sobootloader
canneverbeupdated.Evenmore,theapplicationcanbere-flashed(byUSB)just3
moretimes.
Makefileoptions:
makeBOARD=GPYSECURE=onSECURE_KEY=secure_boot_signing_key.pemENCRYPT_KEY=flash_
encryption_key.binTARGET=[boot|app]
SECURE=onisthemainflag;it'snotoptional
if SECURE=onthefollowingdefaultsareset:
encryptionisenable
secure_boot_signing_key.pemisthesecurebootkey,locatedrelativelytoMakefile
flash_encryption_key.binistheflashencryptionkey,locatedrelativelytoMakefile
Forflashingthebootloaderdigestandtheencryptedversionsofallbinaries:
makeBOARD=GPYSECURE=onflash
Flashing
10.3SecureBootandEncryption
494
Forflashingthe bootloader-reflash-digest.binhastobewrittenataddress0x0,insteadof
the bootloader.bin(ataddress 0x1000).
Buildisdoneusing SECURE=onoption;additionally,allthebinariesarepre-encrypted.
makeBOARD=GPYclean
makeBOARD=GPYSECURE=onTARGET=boot
makeBOARD=GPYSECURE=onTARGET=app
makeBOARD=GPYSECURE=onflash
Manualflashcommand:
python$IDF_PATH/components/esptool_py/esptool/esptool.py--chipesp32--port/dev
/ttyUSB0--baud921600--beforeno_reset--afterno_resetwrite_flash-z--flash_mode
dio--flash_freq80m--flash_sizedetect0x0build/GPY/release/bootloader/bootloader-r
eflash-digest.bin_enc0x8000build/GPY/release/lib/partitions.bin_enc0x10000build/GP
Y/release/gpy.bin_enc_0x10000
OTAupdate
TheOTAshouldbedoneusingthepre-encryptedapplicationimage.
Becausetheencryptionisdonebasedonthephysicalflashaddress,thereare2application
binariesgenerated:
gpy.bin_enc_0x10000whichhastobewrittenatdefaultfactoryaddress: 0x10000
gpy.bin_enc_0x1A0000whichhastobewrittenatthe ota_0partitionaddress
(0x1A0000)
Hint:onMicroPythoninterface,themethod pycom.ota_slot()respondswiththe
addressofthenextOTApartitionavailable(either 0x10000or 0x1A0000).
10.3SecureBootandEncryption
495
MicroPythonLicenseInformation
TheMITLicense(MIT)
Copyright(c)2013-2015DamienP.George,andothers
Permissionisherebygranted,freeofcharge,toanypersonobtainingacopyofthissoftware
andassociateddocumentationfiles(the“Software”),todealintheSoftwarewithout
restriction,includingwithoutlimitationtherightstouse,copy,modify,merge,publish,
distribute,sublicense,and/orsellcopiesoftheSoftware,andtopermitpersonstowhomthe
Softwareisfurnishedtodoso,subjecttothefollowingconditions:
Theabovecopyrightnoticeandthispermissionnoticeshallbeincludedinallcopiesor
substantialportionsoftheSoftware.
THESOFTWAREISPROVIDED“ASIS”,WITHOUTWARRANTYOFANYKIND,
EXPRESSORIMPLIED,INCLUDINGBUTNOTLIMITEDTOTHEWARRANTIESOF
MERCHANTABILITY,FITNESSFORAPARTICULARPURPOSEAND
NONINFRINGEMENT.INNOEVENTSHALLTHEAUTHORSORCOPYRIGHTHOLDERS
BELIABLEFORANYCLAIM,DAMAGESOROTHERLIABILITY,WHETHERINAN
ACTIONOFCONTRACT,TORTOROTHERWISE,ARISINGFROM,OUTOFORIN
CONNECTIONWITHTHESOFTWAREORTHEUSEOROTHERDEALINGSINTHE
SOFTWARE.
Copyright(c)2017,PycomLimited.
ThissoftwareislicensedundertheGNUGPLversion3oranylaterversion,withpermitted
additionalterms.FormoreinformationseethePycomLicencev1.0documentsuppliedwith
thisfile,oravailableathttps://www.pycom.io/opensource/licensing
11.1License
496

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