ESPRESSIF SYSTEMS ESP32WROOM32U Wi-Fi & Bluetooth Internet of Things Module User Manual ESP32 WROOM 32U User Guide EN pages

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ESP32WROOM32U User Manual HTML Version

Users Manual

Version 1.0

ESP32-WROOM-32U

User Guide

About This Guide

This document is intended to help users set up the basic software development

environment for developing applications using hardware based on the ESP32-

WROOM-32U. Through a simple example, this document illustrates how to use ESP-IDF

(Espressif IoT Development Framework), including the menu based conﬁguration wizard,

compiling the ESP-IDF and ﬁrmware download to the ESP32 module.

Release Notes

Date

Version

Release notes

2017.11

V1.0

First release.

Table of Contents 
Introduction!1".............................................................................................................................
1. ESP32-WROOM-32U!1".................................................................................................................
2. ESP-IDF!1".....................................................................................................................................
3. Preparation!1".................................................................................................................................
Get Started!2".............................................................................................................................
1. Standard Setup of Toolchain for Linux!2".......................................................................................
1.1. Install Prerequisites!2".......................................................................................................
1.2. Toolchain Setup!2"............................................................................................................
2. Get ESP-IDF!3"...............................................................................................................................
3. Set up Path to ESP-IDF!3".............................................................................................................
Start a Project!4".........................................................................................................................
Connect!5"..................................................................................................................................
Conﬁgure!6"................................................................................................................................
Build and Flash!7".......................................................................................................................
1. Build and Flash!7"..........................................................................................................................
2. Monitor!8".......................................................................................................................................
SSC Command Reference!9".....................................................................................................
1. op!9"...............................................................................................................................................
2. sta!9"..............................................................................................................................................
3. ap!10".............................................................................................................................................
4. mac!10"..........................................................................................................................................
5. dhcp!11".........................................................................................................................................
6. ip!11"..............................................................................................................................................
7. reboot!12".......................................................................................................................................
8. ram!12...........................................................................................................................................

1. Introduction

1.1. ESP32-WROOM-32U

ESP32-WROOM-32U is a powerful, generic Wi-Fi+BT+BLE MCU module that targets a

wide variety of applications, ranging from low-power sensor networks to the most

demanding tasks, such as voice encoding, music streaming and MP3 decoding. ESP32-

WROOM-32U integrates a U.FL connector.

At the core of this module is the ESP32-D0WD chip.

ESP32 integrates Wi-Fi (2.4 GHz band) and Bluetooth 4.2 solutions on a single chip, along

with dual high performance cores and many other versatile peripherals. Powered by 40 nm

technology, ESP32 provides a robust, highly integrated platform to meet the continuous

demands for efﬁcient power usage, compact design, security, high performance, and

reliability.

Espressif provides the basic hardware and software resources that empowers application

developers to build their ideas around the ESP32 series hardware. The software

development framework provided by Espressif is intended for rapidly developing Internet-

of-Things (IoT) applications, with Wi-Fi, Bluetooth, ﬂexible power management and other

advanced system features.

The RF frequency range is 2.412 GHz to 2.484 GHz. The maximum RF transmit power is

21.5 dbm.

The manufacturer is Espressif Systems (Shanghai) Pte., Ltd (referred to as ESPRESSIF

SYSTEMS), which is shown at the bottom of the product.

1.2. ESP-IDF

The Espressif IoT Development Framework (ESP-IDF for short) is a framework for

developing applications based on the Espressif ESP32. Users can develop applications in

Windows/Linux/MacOS based on ESP-IDF. It is recommended to use Linux distribution.

Lubuntu 16.04 has been used as an example in this document for illustration purposes.

1.3. Preparation

To develop applications for ESP32 you need:

•PC loaded with either Windows, Linux or Mac operating system

•Toolchain to build the Application for ESP32

•ESP-IDF that essentially contains API for ESP32 and scripts to operate the Toolchain

•A text editor to write programs (Projects) in C, e.g. Eclipse

•The ESP32 board itself and a USB cable to connect it to the PC

Espressif

!/121

2017.11

2. Get Started

2.1. Standard Setup of Toolchain for Linux

The quickest way to start development with ESP32 is by installing a prebuilt toolchain. Pick

up your OS below and follow provided instructions.

2.1.1. Install Prerequisites

To compile with ESP-IDF you need to get the following packages:

•CentOS 7:

sudo󰐇yum󰐇install󰐇git󰐇wget󰐇make󰐇ncurses-devel󰐇flex󰐇bison󰐇gperf󰐇python󰐇pyserial

•Ubuntu and Debian:

sudo󰐇apt-get󰐇install󰐇git󰐇wget󰐇make󰐇libncurses-dev󰐇flex󰐇bison󰐇gperf󰐇python󰐇python-serial

•Arch:

sudo󰐇pacman󰐇-S󰐇--needed󰐇gcc󰐇git󰐇make󰐇ncurses󰐇flex󰐇bison󰐇gperf󰐇python2-pyserial

2.1.2. Toolchain Setup

ESP32 toolchain for Linux is available for download from Espressif website:

•for 64-bit Linux:

https://dl.espressif.com/dl/xtensa-esp32-elf-linux64-1.22.0-61-gab8375a-5.2.0.tar.gz

•for 32-bit Linux:

https://dl.espressif.com/dl/xtensa-esp32-elf-linux32-1.22.0-61-gab8375a-5.2.0.tar.gz

Download this ﬁle, then extract it in ~/esp directory

mkdir󰐇-p󰐇~/esp

cd󰐇~/esp

tar󰐇-xzf󰐇~/Downloads/xtensa-esp32-elf-linux64-1.22.0-61-gab8375a-5.2.0.tar.gz

The toolchain will be extracted into ~/esp/xtensa-esp32-elf/ directory.

To use it, you will need to update your ``PATH`` environment variable in ~/.bash_profile ﬁle.

To make xtensa-esp32-elf` available for all terminal sessions, add the following line to your

~/.bash_profile ﬁle:

export󰐇PATH=$PATH:$HOME/esp/xtensa-esp32-elf/bin

Alternatively, you may create an alias for the above command. This way you can get the

toolchain only when you need it. To do this, add different line to your ~/.bash_profile ﬁle:

alias󰐇get_esp32="export󰐇PATH=$PATH:$HOME/esp/xtensa-esp32-elf/bin"

Espressif

!/122

2017.11

2. Get Started

Then when you need the toolchain you can type get_esp32 on the command line and the

toolchain will be added to your PATH.

2.2. Get ESP-IDF

Once you have the toolchain (that contains programs to compile and build the application)

installed, you also need ESP32 speciﬁc API / libraries. They are provided by Espressif in

ESP-IDF repository. To get it, open terminal, navigate to the directory you want to put ESP-

IDF, and clone it using git󰐇clone command:

cd󰐇~/esp

git󰐇clone󰐇--recursive󰐇https://github.com/espressif/esp-idf.git

ESP-IDF will be downloaded into ~/esp/esp-idf.

2.3. Set up Path to ESP-IDF

The toolchain programs access ESP-IDF using IDF_PATH environment variable. This

variable should be set up on your PC, otherwise projects will not build. Setting may be

done manually, each time PC is restarted. Another option is to set up it permanently by

deﬁning IDF_PATH in user proﬁle. To do so, follow instructions speciﬁc to :ref:`Windows

<add-idf_path-to-profile-windows>`, :ref:`Linux and MacOS <add-idf_path-to-profile-

linux-macos>` in section :doc:`add-idf_path-to-profile`.

📖 Note:

•While cloning submodules on Windows platform, the git󰐇clone command may print some output starting

':󰐇not󰐇a󰐇valid󰐇identifier.... This is a known issue but the git clone still succeeds without any

problems.

•Do not miss the --recursive option. If you have already cloned ESP-IDF without this option, run another

command to get all the submodules:

cd󰐇~/esp/esp-idf

git󰐇submodule󰐇update󰐇--init

Espressif

!/123

2017.11

3. Start a Project

Now you are ready to prepare your application for ESP32. To start off quickly, we will

use :example:`get-started/hello_world project from :idf:`examples` directory in IDF.

Copy :example:`get-started/hello_world` to ~/esp directory:

cd󰐇~/esp

cp󰐇-r󰐇$IDF_PATH/examples/get-started/hello_world󰐇.

You can also ﬁnd a range of example projects under the :idf:`examples` directory in ESP-

IDF. These example project directories can be copied in the same way as presented above,

to begin your own projects.

📖 Note:

The ESP-IDF build system does not support spaces in paths to ESP-IDF or to projects.

Espressif

!/124

2017.11

4. Connect

You are almost there. To be able to proceed further, connect ESP32 board to PC, check

under what serial port the board is visible and verify if serial communication works. If you

are not sure how to do it, check instructions in section :doc:`establish-serial-connection`.

Note the port number, as it will be required in the next step.!

Espressif

!/125

2017.11

4. Conﬁgure

5. Conﬁgure

Being in terminal window, go to directory of hello_world application by typing cd󰐇~/esp/

hello_world. Then start project conﬁguration utility menuconfig:

cd󰐇~/esp/hello_world

make󰐇menuconfig

If previous steps have been done correctly, the following menu will be displayed:

In the menu, navigate to Serial flasher config > Default serial port to conﬁgure the serial

port, where project will be loaded to. Conﬁrm selection by pressing enter, save

conﬁguration by selecting < Save > and then exit application by selecting < Exit >.

Here are couple of tips on navigation and use of menuconfig:

•Use up & down arrow keys to navigate the menu.

•Use Enter key to go into a submenu, Escape key to go out or to exit.

•Type ? to see a help screen. Enter key exits the help screen.

•Use Space key, or Y and N keys to enable (Yes) and disable (No) conﬁguration items

with checkboxes “[*]“.

•Pressing ? while highlighting a conﬁguration item displays help about that item.

•Type / to search the conﬁguration items.

📖 Notes:

•On Windows, serial ports have names like COM1. On MacOS, they start with /dev/cu.. On Linux, they

start with /dev/tty. (See :doc:`establish-serial-connection` for full details.)

•If you are Arch Linux user, navigate to SDK tool configuration and change the name of Python 2

interpreter from python to python2.

•Most ESP32 development boards have a 40 MHz crystal installed. However, some boards use a 26 MHz

crystal. If your board uses a 26MHz crystal, or you get garbage output from serial port after code upload,

adjust the :ref:`CONFIG_ESP32_XTAL_FREQ_SEL` option in menuconfig.

Espressif

!/126

2017.11

5. Build and Flash

6. Build and Flash

6.1. Build and Flash

Now you can build and ﬂash the application. Run:

make󰐇flash

This will compile the application and all the ESP-IDF components, generate bootloader,

partition table, and application binaries, and ﬂash these binaries to your ESP32 board.

esptool.py󰐇v2.0-beta2

Flashing󰐇binaries󰐇to󰐇serial󰐇port󰐇/dev/ttyUSB0󰐇(app󰐇at󰐇offset󰐇0x10000)...

esptool.py󰐇v2.0-beta2

Connecting........___

Uploading󰐇stub...

Running󰐇stub...

Stub󰐇running...

Changing󰐇baud󰐇rate󰐇to󰐇921600

Changed.

Attaching󰐇SPI󰐇flash...

Configuring󰐇flash󰐇size...

Auto-detected󰐇Flash󰐇size:󰐇4MB

Flash󰐇params󰐇set󰐇to󰐇0x0220

Compressed󰐇11616󰐇bytes󰐇to󰐇6695...

Wrote󰐇11616󰐇bytes󰐇(6695󰐇compressed)󰐇at󰐇0x00001000󰐇in󰐇0.1󰐇seconds󰐇(effective󰐇920.5󰐇kbit/s)...

Hash󰐇of󰐇data󰐇verified.

Compressed󰐇408096󰐇bytes󰐇to󰐇171625...

Wrote󰐇408096󰐇bytes󰐇(171625󰐇compressed)󰐇at󰐇0x00010000󰐇in󰐇3.9󰐇seconds󰐇(effective󰐇847.3󰐇kbit/

s)...

Hash󰐇of󰐇data󰐇verified.

Compressed󰐇3072󰐇bytes󰐇to󰐇82...

Wrote󰐇3072󰐇bytes󰐇(82󰐇compressed)󰐇at󰐇0x00008000󰐇in󰐇0.0󰐇seconds󰐇(effective󰐇8297.4󰐇kbit/s)...

Hash󰐇of󰐇data󰐇verified.

Leaving...

Hard󰐇resetting...

Espressif

!/127

2017.11

5. Build and Flash

If there are no issues, at the end of build process, you should see messages describing

progress of loading process. Finally, the end module will be reset and “hello_world”

application will start.

If you'd like to use the Eclipse IDE instead of running make, check out the :doc:`Eclipse

guide <eclipse-setup>`.

6.2. Monitor

To see if “hello_world” application is indeed running, type make󰐇monitor. This command is

launching :doc:`IDF Monitor <idf-monitor>` application:

$󰐇make󰐇monitor

MONITOR

---󰐇idf_monitor󰐇on󰐇/dev/ttyUSB0󰐇115200󰐇---

---󰐇Quit:󰐇Ctrl+]󰐇|󰐇Menu:󰐇Ctrl+T󰐇|󰐇Help:󰐇Ctrl+T󰐇followed󰐇by󰐇Ctrl+H󰐇---

ets󰐇Jun󰐇󰐇8󰐇2016󰐇00:22:57

rst:0x1󰐇(POWERON_RESET),boot:0x13󰐇(SPI_FAST_FLASH_BOOT)

ets󰐇Jun󰐇󰐇8󰐇2016󰐇00:22:57

...

Several lines below, after start up and diagnostic log, you should see “Hello world!” printed

out by the application.

...

Hello󰐇world!

Restarting󰐇in󰐇10󰐇seconds...

I󰐇(211)󰐇cpu_start:󰐇Starting󰐇scheduler󰐇on󰐇APP󰐇CPU.

Restarting󰐇in󰐇9󰐇seconds...

Restarting󰐇in󰐇8󰐇seconds...

Restarting󰐇in󰐇7󰐇seconds...

To exit monitor use shortcut Ctrl+]. To execute make󰐇flash and make󰐇monitor in one shoot

type make󰐇flash󰐇monitor. Check section :doc:`IDF Monitor <idf-monitor>` for handy

shortcuts and more details on using this application.

That's all what you need to get started with ESP32!

Now you are ready to try some other :idf:`examples`, or go right to developing your own

applications.

Espressif

!/128

2017.11

6. SSC Command Reference

7. SSC Command Reference

Here lists some common Wi-Fi commands for you to test the module.

7.1. op

Description

op commands are used to set and query the Wi-Fi mode of the system.

Example

op󰐇-Q󰐇

op󰐇-S󰐇-o󰐇wmode

Parameter

7.2. sta

Description

sta commands are used to scan the STA network interface, connect or disconnect AP, and

query the connecting status of STA network interface.

Example

sta󰐇-S󰐇[-s󰐇ssid]󰐇[-b󰐇bssid]󰐇[-n󰐇channel]󰐇[-h]

sta󰐇-Q

sta󰐇-C󰐇[-s󰐇ssid]󰐇[-p󰐇password]

sta󰐇-D

Parameter

Table 6-1. op Command Parameter

Parameter

Description

-Q

Query Wi-Fi mode.

-S

Set Wi-Fi mode.

wmode

There are 3 Wi-Fi modes:

•mode = 1: STA mode

•mode = 2: AP mode

•mode = 3: STA+AP mode

Table 6-2. sta Command Parameter

Parameter

Description

-S scan

Scan Access Points.

Espressif

!/129

2017.11

6. SSC Command Reference

7.3. ap

Description

ap commands are used to set the parameter of AP network interface.

Example

ap󰐇-S󰐇[-s󰐇ssid]󰐇[-p󰐇password]󰐇[-t󰐇encrypt]󰐇[-n󰐇channel]󰐇[-h]󰐇[-m󰐇max_sta]

ap󰐇–Q

ap󰐇–L

Parameter

7.4. mac

Description

mac commands are used to query the MAC address of the network interface.

Example

mac󰐇-Q󰐇[-o󰐇mode]

-s ssid

Scan or connect Access Points with the ssid.

-b bssid

Scan the Access Points with the bssid.

-n channel

Scan the channel.

-h

Show scan results with hidden ssid Access Points.

-Q

Show STA connect stutus.

-D

Disconnected with current Access Points.

Parameter

Description

Table 6-3. ap Command Parameter

Parameter

Description

-S

Set AP mode.

-s ssid

Set AP ssid.

-p password

Set AP password.

-t encrypt

Set AP encrypt mode.

-h

Hide ssid.

-m max_sta

Set AP max connections.

-Q

Show AP parameters.

-L

Show MAC Address and IP Address of the connected station.

Espressif

!/1210

2017.11

6. SSC Command Reference

Parameter

7.5. dhcp

Description

dhcp commands are used to enable or disable dhcp server/client.

Example

dchp󰐇-S󰐇[-o󰐇mode]

dhcp󰐇-E󰐇[-o󰐇mode]

dhcp󰐇-Q󰐇[-o󰐇mode]

Parameter

7.6. ip

Description

ip command are used to set and query the IP address of the network interface.

Example

ip󰐇-Q󰐇[-o󰐇mode]

ip󰐇-S󰐇[-i󰐇ip]󰐇[-o󰐇mode]󰐇[-m󰐇mask]󰐇[-g󰐇gateway]

Table 6-4. mac Command Parameter

Parameter

Description

-Q

Show MAC address.

-o mode

•mode = 1: MAC address in STA mode.

•mode = 2: MAC address in AP mode.

Table 6-5. dhcp Command Parameter

Parameter

Description

-S

Start DHCP (Client/Server).

-E

End DHCP (Client/Server).

-Q

show DHCP status.

-o mode

•mode = 1 : DHCP client of STA interface.

•mode = 2 : DHCP server of AP interface.

•mode = 3 : both.

Espressif

!/1211

2017.11

6. SSC Command Reference

Parameter

7.7. reboot

Description

reboot command is used to reboot the board.

Example

reboot

7.8. ram

ram command is used to query the size of the remaining heap in the system.

Example

ram

Table 6-6. ip Command Parameter

Parameter

Description

-Q

Show IP address.

-o mode

•mode = 1 : IP address of interface STA.

•mode = 2 : IP address of interface AP.

•mode = 3 : both

-S

Set IP address.

-i ip

IP address.

-m mask

Subnet address mask.

-g gateway

Default gateway.

Espressif

!/1212

2017.11

Disclaimer and Copyright Notice

Information in this document, including URL references, is subject to change without

notice.

THIS DOCUMENT IS PROVIDED AS IS WITH NO WARRANTIES WHATSOEVER,

INCLUDING ANY WARRANTY OF MERCHANTABILITY, NON-INFRINGEMENT, FITNESS

FOR ANY PARTICULAR PURPOSE, OR ANY WARRANTY OTHERWISE ARISING OUT

OF ANY PROPOSAL, SPECIFICATION OR SAMPLE.

All liability, including liability for infringement of any proprietary rights, relating to use of

information in this document is disclaimed. No licenses express or implied, by estoppel or

otherwise, to any intellectual property rights are granted herein.

The Wi-Fi Alliance Member logo is a trademark of the Wi-Fi Alliance. The Bluetooth logo is

a registered trademark of Bluetooth SIG.

All trade names, trademarks and registered trademarks mentioned in this document are

property of their respective owners, and are hereby acknowledged.

Espressif IOT Team"

www.espressif.com





FCCLabel:TheFCCIDisonthefrontofthedevice.Itiseasilyvisible.

ThedeviceFCCIDis2AC7Z‐ESP32WROOM32U.

Alabelwiththefollowingstatementsmustbeattachedtothehostendproduct:

ThisdevicecontainsFCCID:2AC7Z‐ESP32WROOM32U.

Themanualprovidesguidancetothehostmanufacturerwillbeincludedinthedocumentationthatwill

beprovidedtotheOEM.

Themoduleislimitedtoinstallationinmobileorfixedapplications.

Theseparateapprovalisrequiredforallotheroperatingconfigurations,includingportableconfigurations

anddifferentantennaconfigurations.

TheOEMintegratorsareresponsibleforensuringthattheend‐userhasnomanualorinstructionsto

removeorinstallmodule.

ThemoduleislimitedtoOEMinstallationONLY.



Modulegrantee(thepartyresponsibleforthemodulegrant)shallprovideguidancetothehost

manufacturerforensuringcompliancewiththePart15SubpartBrequirements.



Thehostmanufacturerisresponsibleforadditionaltestingtoverifycomplianceasacompositesystem.

WhentestingthehostdeviceforcompliancewiththePart15SubpartBrequirements,thehost

manufacturerisrequiredtoshowcompliancewiththePart15SubpartBwhilethetransmittermodule(s)

areinstalledandoperating.Themodulesshouldbetransmittingandtheevaluationshouldconfirmthat

themodule’sintentionalemissionsarecompliant(i.e.fundamentalandoutofbandemissions)withthe

Radioessentialrequirements.Thehostmanufacturermustverifythattherearenoadditional

unintentionalemissionsotherthanwhatispermittedinthePart15SubpartBoremissionsarecomplaint

withtheRadioaspects.



CAUTION:

Anychangesormodificationsnotexpresslyapprovedbythegranteeofthisdevicecouldvoidtheuser’s

authoritytooperatetheequipment.







FCCRFExposureRequirements

ThisdevicecomplieswithFCCRFradiationexposurelimitssetforthforanuncontrolledenviroment.

Theantenna(s)usedforthistransmittermustnotbeco‐locatedoroperatinginconjunctionwithany

otherantennaortransmitterandmustbeinstalledtoprovideaseparationdistanceofatleast20cmfrom

allpersons.



FCCRegulations

Thisdevicecomplieswithpart15oftheFCCRules.Operationissubjecttothefollowingtwoconditions:

(1)Thisdevicemaynotcauseharmfulinterference,and(2)thisdevicemustacceptanyinterference

received,includinginterferencethatmaycauseundesiredoperation.

ThisdevicehasbeentestedandfoundtocomplywiththelimitsforaClassBdigitaldevice,pursuantto

Part15oftheFCCRules.

Theselimitsaredesignedtoprovidereasonableprotectionagainstharmfulinterferenceinaresidential

installation.Thisequipmentgenerates,usesandcanradiateradiofrequencyenergyand,ifnotinstalled

andusedinaccordancewiththeinstructions,maycauseharmfulinterferencetoradiocommunications.

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ESPRESSIF SYSTEMS ESP32WROOM32U Wi-Fi & Bluetooth Internet of Things Module User Manual ESP32 WROOM 32U User Guide EN pages

ESPRESSIF SYSTEMS (SHANGHAI) PTE LTD Wi-Fi & Bluetooth Internet of Things Module ESP32 WROOM 32U User Guide EN pages

Users Manual

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