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Microcontroller Board User Manual

Microcontroller Board V4 User Manual

Table of Contents
Introduction ................................................................................................................ 3
Overview ............................................................................................................... 3
Features ................................................................................................................ 4
Included in the Box ............................................................................................... 4
Operation .................................................................................................................... 5
Operational Modes ............................................................................................... 5
Connecting to the PC for Programming................................................................ 5
Customizing Board Operation .............................................................................. 6
Interfacing with External Circuits ......................................................................... 6
Board Modules ............................................................................................................ 7
Power Supply ........................................................................................................ 7
On-board USB Programmer .................................................................................. 8
Debugging Module ............................................................................................... 8
HD44780 Based LCD ............................................................................................. 9
4x4 KEYPAD and Co-Processor............................................................................ 10
A2D Reference .................................................................................................... 11
Real Time Clock ................................................................................................... 11
3.7.1 Using the Real Time Clock ........................................................................... 11
Main I/O Bus ....................................................................................................... 15
I2C BUS ................................................................................................................ 16
Main PIC Device .................................................................................................. 16
PIC – Arduino Interface ....................................................................................... 17
Programming and Software ...................................................................................... 18
Overview ............................................................................................................. 18
Using the Onboard Programmer ........................................................................ 19
Sample Codes...................................................................................................... 21
More Advanced Operations ...................................................................................... 23
Using the Board as a Standalone Programmer .................................................. 23
Activating the Programmer-To-Go Feature ........................................................ 24
Re-imaging Firmware for the Onboard Programmer ......................................... 24
Re-imaging Firmware for the Keypad Encoder PIC ............................................ 25
APPENDIX 1: List of all Removable Parts .......................................................................... 26

Microcontroller Board V4 User Manual

Introduction
Overview
The PIC Dev Bugger development board was designed as a platform for development of
mobile robotic control solution. Modules of the board includes: a full-speed USB2.0
programmer, 4x4 matrix keypad input, up to 4x20 character LCD, Real Time Clock, Analog
to digital conversion, Arduino slave interface, and I2C serial port. One especially useful
feature of this development board is the debug module, which monitor states of all user
accessible pins of the onboard PIC microcontroller. Additionally, the user can pull up or
down each pin connected to the debug module directly from the board, which allows
quick and effective code debugging.
This board is especially designed to suit the needs of students learning to develop for
embedded systems. The form factor and features of the board allows it to be used both
as an exclusive code development platform or in system as the main processing and
control system in a final design.

Figure 1: The PIC Microcontroller board

Microcontroller Board V4 User Manual

Features
 Open, modular, and simple design for learning purposes
 Supports 18-, 28-, and 40-pin packages for PIC16 and 18 families
 In-circuit PICkit™ 3 compatible High Voltage Programmer (works with MPLABX®
IDE)
 Dual power source, USB or DC power supply input (from 7.5VDC to 17VDC)
 Dual system voltage support (5V and 3.3V system VCC)
 Debugging Module with 32 indicator LEDs and signal-emulation switches
 Keypad encoder chip is a full featured PIC, whose firmware can be modified for
extra memory, parallel processing, and/or I/O pin extension for the primary MCU
 Real Time Clock peripheral with 32.768khz crystal and battery socket (RTC chip
included)
 On-board socket for Hitachi HD44780 compatible LCD with contrast and backlight
controls, support size up to 4x20 characters
 On-board 4x4 matrix keypad socket and PIC based encoder
 40-pin I/O bus with ribbon cable connector
 Interchangeable oscillator clock (10MHz crystal included), with dedicated
oscillator socket for 18-pin PIC.
 I2C bus expansion socket
 On-board adjustable ADC voltage reference
 Arduino Nano board interface, with individually selectable pin pass-through to
PIC.
 Arduino shield connector, with pin pass-through from both PIC and Arduino.

Included in the Box
The development kit come included with the following items:








PIC Microcontroller development board
CD/URL from which to download necessary software, drivers, and sample codes
USB A to B cable
40-pin I/O bus cable
HD44780-controlled LCD display (2x16 characters)
4x4 matrix keypad
AC-DC adaptor unit (120V AC to 12V DC,.1A)

Microcontroller Board V4 User Manual

Operation
Operational Modes
The PIC Microcontroller board has two modes of operation, as follows:

Programming: Used to load compiled HEX code onto the main PIC device, as well as
debugging of code on device. To enter this mode, flip the PROG/RUN slide
switch of the programmer module to the PRG position. In this mode, the
VPP, PGC and PGD pins of the main PIC device are disconnected from the
main I/O bus, and connected instead to the programmer module. A PC
application compatible with the PICkit™ 3 programmer, such as MPLABX®
IDE, can be used to control loading and debugging in this mode.

Execution:

This is the primary operational mode of the board. To enter this mode,
flip the PROG/RUN slide switch of the programmer to the RUN position.
In this mode, All I/O pins of the main PIC device are connected to the I/O
bus, and code executes freely. The onboard programmer can be used
independently as a PICkit™ 3 programmer for programming of external
PIC boards or the onboard PIC keypad encoder. The ICSP_EXT headers can
be used for this purpose when the development board is in this mode.

Connecting to the PC for Programming
To load HEX code to the PIC device, the Microcontroller board must connect to a PC:
1. Install the MPLABX IDE and/or MPLABX IPE distributed by Microchip
a. The development board will be recognized as a PICkit™ 3 programmer
2. Connect the Microcontroller board to the PC using the included USB cable.
3. Power the board and turn it on. The board can be powered by the USB cable.
However, use of the included wall adaptor in conjunction is strongly
recommended.
4. Set the board to Programming mode. (Section 2.1)
5. Flip the power switch to the ON position. (Section 3.1)
6. The PC should detect the Microcontroller and install the driver automatically.
7. The PIC device on the board is now ready to be programmed. (Section Error!
eference source not found.)

Microcontroller Board V4 User Manual

Customizing Board Operation
The Microcontroller board was designed with versatility in mind. To customize the
operation of the board, several configuration jumpers and switches have been included,
which must be set by the user. Before using the board for the first time, please ensure
that the jumpers for each module have been configured as desired. More information
about jumper settings for individual modules can be found in Section 3.

Figure 2:
Jumper

For those unfamiliar with jumpers, a jumper is a set of 2 or more exposed
pins that can be connected adjacently in pairs, using a ‘shunt’. When two
pins of the jumper are connected to each other, they are ‘shorted’. As an
example, if pins 1 and 2 in the figure are connected using a shunt, then we
say we have ‘shorted’ pins 2+3, and we have configured the board for use
with a P18F type microcontroller as labeled above the jumper.

Interfacing with External Circuits
While the board is operating in Execution mode, all I/O pins of the PIC microcontroller
are directly connected to the main I/O bus socket. Using the provided ribbon cable, this
bus can be used to interface directly with external circuitry. The I/O bus can provide some
power at the working voltage of the board (selectable between 5V and 3.3V) and ground
reference in addition to direct access to the pins of the main PIC. No high-power devices
or circuitry (such as motors, fans, solenoids, or high powered lights) shall be powered
from the VCC output on the development board. Also, note that the Keypad peripheral
adds an extra pin to the bus (KPD pin), for on-the-fly enable/disable control, as described
in Section 3.5. A detailed description of the pin connections on the ribbon cable is given
in Section 3.8.

WARNING: the VCC supply on the bus is NOT recommended as an alternate method of
powering the Microcontroller board. Especially when the board is operating in 3.3V
system voltage mode. Power should always be supplied through the DC input jack when
the board is used as part of an embedded system (voltage of 7.5 to 12 volts are
recommended). The onboard power supply module will ensure delivery of clean DC
power to all aspects of the development board.
NO guarantee is made for the continued integrity of the board in cases of such usage.

Microcontroller Board V4 User Manual

Board Modules
Power Supply

Figure 3: Power Supply

The Power Supply module is designed to
take DC input of 7.5V to 17V, and output
regulated 5V and 3.3V for all modules to
share including the I/O bus. It is able to also
receive 5V USB power from the host PC.
Either of these sources can be used as
power supply, although a dedicated DC
power supply is strongly recommended.
The max current supplied by the power
module is limited to 1.25A in total, 3.3V
and 5V rails combined. A small fuse is
present to protect the power supply from
operating above its current limit. (Little
Fuse 372 Series, TR5 Size)

The input connector is a female
5.5×2.1mm jack, which is compatible with many commonplace adaptors. Wall adaptors
of any polarity (center positive or center negative) may be used since the input is rectified.
A single two-pole slide switch controls power to the entire board by interrupting the
positive power terminal immediately after rectification, as well as interrupting the
positive power terminal from the USB. In the ON position, the board is powered, as
indicated by both green LEDs for 5V and 3.3V; in the OFF position, all modules are
unpowered. The red V_IN indicates the status at the DC input jack immidiately after
rectificatoin, it will be luminated to indicate present of DC input power when the power
switch is in the ON position.

Microcontroller Board V4 User Manual

On-board USB Programmer
The Microcontroller board includes
an on-board USB PIC programmer.
The programmer is compatible with
PICkit™ 3 Debugger / Programmer
and will be recognized by MPLABX
IDE and IPE as a PICkit™ 3
programmer.

Figure 4: Onboard Programmer

The programmer operates in High
Voltage Programming (HVP) mode
given a supply voltage of 5V. It
incorporates an internal voltage
converter that boosts the 5V supply
to 12V needed for HVP.

To enter Programming Mode, set the slide switch to the PRG position, and to enter
Executing mode, set the slide switch to the RUN position. Three LEDs indicate the status
of the programmer, when the board is first power on, all LEDs should illuminate. When
the programmer finishes initialization, and enters standby mode, both status LEDs will
turn off leaving only the red ACTIVE LED illuminated to indicate the programmer is ready.
Note: that the onboard PICkit™ 3 does not posses the push button for the ProgrammerTo-Go feature, however it is possible to activate the feature if desired, see Section 5.2 for
more detail.

Debugging Module

Figure 5: Indicator LEDs

The Debugging module allows the user to monitor
the state of each I/O pins of the main PIC device
through 32 indicator LEDs. These indicators are fully
buffered, as such they do not indice any load on the
signal lines in which they are monitor – in other
words, they can safely monitor the logic states of
low-power sensor signals. However, it should be
noted that unless specific lines are connected to
external signals or are driven by the I/O ports, their
indicators may change unpredictably since they are
floating.

Microcontroller Board V4 User Manual
The indicators can be disabled in four separate columns
through the included (LED DEBUG) DIP switch, in order to
reduce current draw on the boar’s power supply when not
needed. The DIP switches, from left to right, corrospond to
columns: PORTA/E PORTB PORTC PORTD respectively.
The Microcontroller board also comes with 32 DIP switches
to provide input to the pins of the main PIC for debugging
purposes. Each switch corresponds to an pin on the main PIC
as indicated by the marking next to each switch. Each DIP
switch has 3 states: High (5V or 3V), Floating (disconnected),
and Ground (0V). The switchs are in the middle position by
default, which disconnects its corrosponding pin and leave it
floating. This is the perferred state if the user wishes to hand
Figure 6: Signal Switches
control of the pin to the PIC or external circutry connected
to the I/O bus. The switches can be pulled to the left or right
to send a high or low state to the PIC. It is importat to be careful to ensure the pin state
is not enforced by the PIC or any external input before using the signal emulation switchs.
A conflict between the switchs and the PIC could lead to unexpected behaviors of the
development board.

HD44780 Based LCD

Figure 7: LCD

This peripheral module
allows a HD44780-based LCD
display
to
be
easily
connected to the board.
Controls are provided for
backlight and contrast, and
two equivalent headers have
been provided to support
different LCD orientations
(Up/Down facing).

The board have been designed to accommodate both a 2x16 character display or a larger
4x20 character display. The two numbers refer to the number or rows and number of
characters per row. A 2x16 LCD will have 2 rows with 16 characters each, while a 4X20
LCD will allow 4 rows with 20 character per row. Note that 4X20 (80 characters) is the
maximum possible size for the HD44780 LCD controller.

Microcontroller Board V4 User Manual
HD44780(LCD)
RS
R/W
E
D4
D5
D6
D7

PIC I/O Pin
RD2
GND
RD3
RD4
RD5
RD6
RD7

Since the HD44780 protocol supports either 8bit or 4-bit data transfer modes, the
Microcontroller board has been configured to
use 4-bit mode in the interest of conserving I/O
pins. The HD44780 interface pins have been
mapped to the PIC I/O ports as shown in Table
1.

Table 1: LCD I/O Map

4x4 KEYPAD and Co-Processor

Figure 8: Keypad

4x4 matrix keypads are commonly used in
microcontroller applications, this module
was included to simplify the required
interface. Two equivalent headers provide a
socket for the keypad in different
orientations,
and
a
PIC18F2550
microcontroller encodes the 8-line matrix
input into simple to parse 4-bit hex data.
The data pins for the encoder PIC are
connected to PORTB<7:4> and the ‘data
available’ pin (active high) is connected to
RB1.

The Keypad module can be disabled on-the-fly through the special KPD pin on the I/O bus
If KPD is set high, the keypad will be disabled, and if set low, the keypad will be enabled.
When the keypad module is enabled, two 47HC4066 buffer chips isolate the keypad data
pins from outputs on the PIC I/O bus. Disconnecting the keypad data pins protects them
from interference from external circuitry and increase reliability of keypad inputs. When
the keypad is disabled, the encoder PIC will set its output pins to high impedance mode
(disconnected), also PORTB<7:4> and RB1 of the main PIC will be made accessible to the
user. Note that KPD can be controlled either by external circuitry or directly by the PIC by
connecting it to one of the ports on the I/O bus.
Additional to acting as the keypad encoder chip, the PIC18F2550 also serves as a CoProcessor to the main PIC. A dedicated programming header and oscillator socket allows
it to operate independently or in conjuncture with the main PIC.

Microcontroller Board V4 User Manual

A2D Reference
The Microcontroller board has been equipped
with two potentiometers, R12 and R13 to set the
voltage reference levels for the Analog to Digital
Converter (ADC). To enable these references,
short JP4 and JP5; if they are both left
unconnected, the references are disabled.
Figure 9: A2D

Short JP4 to enable Vref on RA2
Short JP5 to enable Vref on RA3

Note: To enable voltage references, the PIC also need to be configured alongside the
insertion of jumper links. Refer to data sheets of PIC device used for instructions.

Real Time Clock
A Real Time Clock (RTC) and CR2023 coin cell battery allow for offchip timekeeping, even when the rest of the board is unpowered.
The circuit is designed for a DS1307 or DS1308 RTC chip,
interfaced through I2C on pins RC3 and RC4.
To enable, short JP6 and JP7

Figure 10: RTC

Note: A DS1307 or a DS1308 RTC chip may be included. The two
chips are extremely similar in operation. The DS1308 chip come in
a surface mount package, while the DS1307 chip take form of an
8 pin Dual-in-line (DIP) package, and will be supplied with a
matching socket on the board. The CR2023 coin cell battery is not
included with the development board.

Note 2: The RTC module was designed to be used with backup power (the 3V disk battery)
and therefore must have the battery in the socket to ensure consistent operation.
3.7.1
Using the Real Time Clock
The DS1307 real time clock can be used to keep track of time in seconds, minutes, hours,
days, months, and years. The numbers of days in months are automatically adjusted,
including leap years. The hours function allows the chip to keep time in either 12 or 24hour format with AM/PM indicator for 12-hour format. The advantage of the off-chip
timekeeping functionality of the RTC is to free the microcontroller from the task so that
it may focus on other tasks. For more detail on the DS1307 real time clock, please refer
to Chapter 7 of the AER201 course notes.
The RTC communicates with the main PIC microcontroller through the I2C protocol and
acts as a slave device with a 7-bit address of 1101 000X (where X denotes if the transaction
© Personal Mechatronics Lab, 2016

Microcontroller Board V4 User Manual
is a read or a write in in a I2C transaction). In order to use the RTC, the main PIC must be
configured as a MSSP device or master device for I2C. The master device is responsible for
initiating and controlling the clock pulse for all slave devices, including the RTC. The
sample code for configuration and operation of the RTC chip is available to students as a
MATLABX project: PIC18_RTC.X
The C libraries for I2C communication is also included in the sample MPLABX project, the
library can be moved to any new project and provide a basic framework for
communication with I2C peripherals.
Importing the I2C communication libraries
To communicate with the RTC chip, the I2C library must be first added to any new project
you crate. To do this, follow the steps below:
1. Copy I2C.c and I2C.h from the RTC sample code into your project directory
2. Open MPLABX and open the project where the RTC is to be used
3. If there isn’t a window displaying the list of open projects, Go to Window click
Projects. (or press Control – 1)
4. In the Project window where all the files in the project are listed. Right click on
the project you are working on, and select Add Existing Item…
5. Select and add I2C.h and I2C.c to your project.
6. In any source files in which the user code calls functions from the I2C library,
the directive #include "I2C.h" must be included at the start of the .c file.
Writing to RTC registers
Before beginning, the PIC must be configured as the I2C master with an appropriate clock
rate. This can be done by calling I2C_Master_Init(10000); which will configure the PIC as
I2C master with a clock rate of 100KHz.
To write to registers of the RTC, first send a command on the I2C bus with the slave
address, appended with a zero to indicate a write operation:
I2C_Master_Start(); //Start condition
I2C_Master_Write(0b11010000); //7 bit RTC address + Write
I2C_Master_Write(0x00); //Set location of register to write to

After the register address have been selected, the data intended to be written to the
registers can be send one after another on the bus. The chip will automatically increment
the registers after receiving each byte of data, so there is no need to restate each register
address for successive writes. The code required is below:

Microcontroller Board V4 User Manual
for(char i=0; i<7; i++){
I2C_Master_Write(happyNewYear[i]);
}
I2C_Master_Stop();
// Send stop condition

Where happyNewYear is an array that holds, in order, the register data required to set
the time for the RTC. See Figure 11 for a flow chart of the data write sequence.

Figure 11: Data Write – DS1307 In Receiver Mode

Note: The RTC stores date and time values in BCD form in its registers, so there is no need
to cast the decimal number representation into hex before sending them to the registers.
For example, to set a time of: “2016 December 31 Saturday 23:59:45”, simply send
{‘0x45’,’0x59’,’0x23’,’0x07’,’0x31’,’0x12’,’0x16’} to the RTC.
Reading from RTC registers
The procedure for reading values back from the RTC is very similar to the writing
sequence. First, ensure the I2C bus has been initiated using the I2C_Master_Init(10000);
command (Initialization is only required once at the start of the program). Then send the
address of the slave over the bus, appended with a ‘1’ to indicate a read operation:
I2C_Master_Start();
I2C_Master_Write(0b11010001); //7 bit RTC address + Read

When the read bit (last bit of the address) is sent at the start of the transaction without
specifying any register address, the RTC chip will send back data starting from register
0x00 continuously until the master terminated the transaction by a “not acknowledge”
signal. The data can be received by continuously calling I2C_Master_Read(1);
for(unsigned char i=0;i<0x06;i++){
time[i] = I2C_Master_Read(1); // Receive n-1 bytes with ACK
}

Once all except the last desired data bytes have been received, the master should receive
the last byte of data following by a “not acknowledge”:
time[6] = I2C_Master_Read(0);
I2C_Master_Stop();

//Final Read without ACK
//Stop receiving sequence

Microcontroller Board V4 User Manual
Alternatively, if one does not wish to read the RTC registers starting at register 0x00, a
work pointer can be first written to the RTC before initiating the receiving sequence using
the following codes:
I2C_Master_Start(); //Start condition
I2C_Master_Write(0b11010000); //7 bit RTC address + Write
I2C_Master_Write(0x00); //Set memory pointer to seconds
I2C_Master_Stop(); //Stop condition

The operation flow charts for both receiving modes can be seen in Figure 12 and Figure
13.

Figure 13: Data Read – DS1307 In Transmitter Mode

Figure 12: Data Read (Write Pointer, Then Read) – DS1307 In Receiver Mode

Microcontroller Board V4 User Manual

Main I/O Bus
A 40-pin bus has been provided to allow direct access to
each I/O pin available on the PIC, as well as a special
purpose pin for enabling/disabling the keypad at runtime
(see Section 3.5). The pin-outs for the socket shown in
Figure 14.
It is important to note that to access RA6 and RA7, jumpers
JP8 and JP9 must be properly set, as described in
Section 3.10 .
Also, the user needs to note that RA6 and RA7 are not
available PICs without internal oscillators, as they are
dedicated oscillator pins. For PICs with internal oscillators
such as PIC18s and newer generation PIC16s, RA6 and RA7
can be configured as work as general purpose IO when the
internal oscillator block is used.
It is important to note that these I/O busses are connected
directly to the PIC, the user should be careful to not present
voltages above 5V or below 0V to any of these pins to avoid
damage to the PIC chip or other peripherals.

Figure 14: IO Bus Pin-Outs,
Top View

Table 2: Pins Used by Onboard Modules below lists all pins
used by peripheral modules on the development board. The
user should be careful with using these pins for external I/O
to avoid conflict with pin assignment with existing libraries

and modules.
Module
RTC
LCD
Keypad
A2D
Programmer
Arduino
Main Oscillator
I2C
Debug

Pins (Bolded pins can be disconnected, see section on the
respective modules for more information)
RC3, RC4
RD2, RB3, RD4, RD5, RD6, RD7
RB4, RB5, RB6, RB7, RB1
RA2, RA3
RB5, RB6, MCLR
RA0, RA1, RA4, RA5, RE2, RC3, RC4, RC5, RC6, RC7, RD0:7
RA6, RA7
RC3 RC4
RE0:1, RA0:5, RB0:7, RC0:7, RD0:7
Table 2: Pins Used by Onboard Modules

Microcontroller Board V4 User Manual

I2C BUS
An I2C bus socket has also been provided to allow a separate I2C bus to
a peripheral device. A 10-bin ribbon cable connector (not supplied with
board) can be used for this purpose. The pinouts of the socket are
shown to the left.
Note that 10K pullup resistors are included with the RTC module and is
in circuit when the RTC module jumpers are inserted. It is
recommended that only on set up pullup resistors be used on the I2C
Figure 15: I2C
bus. There is no need to implement pullup resistors on external
circuitry connected to this breakout header if the RTC module is in use. Otherwise,
separate pullup resistors are required.

Main PIC Device
This section of the board has
several sockets for PIC devices of
different sizes. Only one socket
may be occupied at a time,
otherwise bus conflicts will arise.
The Microcontroller board is
primarily intended to be used
with a PIC18F4620, although
most other PIC devices in the
PIC16F and PIC18F families are
currently supported.
Additionally, some PIC16F and
PIC18F devices allow the user to
Figure 16: Main PIC Module
employ an internal oscillator and
configure RA6 and RA7 as general purpose I/O pins. If this is intended, jumpers JP9 and
JP8 must be set as follows:
Short pins 1 and 2 to use external oscillator
Short pins 2 and 3 to enable RA6, RA7
Of course, the appropriate configurations must also be set from within the code.
A switch is also present for user to select the global VCC voltage between 5V and 3.3V for
low voltage compatible PICs. It is important to note that this switch is global to the board,

Microcontroller Board V4 User Manual
and if 3.3V operation is desired, the LCD, RTC and Arduino board must be switched to
their 3.3V compatible alternatives.

PIC – Arduino Interface
This section of the board allows
interface with Arduino boards and
shields. An Arduino Nano board can be
inserted into the headers in the
“ARDUINO NANO BOARD” section, and
switch ban S2 and S3 enables pin to pin
connection between the PIC and
Arduino board and shield.
Pins on the Arduino board header is
always connected to matching pins on
the shield connector, regardless of the
positions of the switches. As such, this
module can also be used simply as a
shield adapter for a standard Arduino
Nano board.
5V power for the Arduino board is
Figure 17: PIC – Arduino Interface
connected directly to the 5V power rails
of the development board, and the
3.3V supply on the Arduino is connected to the 3.3V power rail through a diode that
prevents current draw from the 3.3V regulators on board the Arduino board.
The PIC – Arduino connection controller by each switch are shown in the table to the left
of each switch bank on the board. The pin connects are designed in such a way that the
PIC and Arduino is able to communicate through various busses including Serial
Peripherals Interface (SPI), Universal Asynchronous Receiver/Transmitter (UART) and I2C.
Also, the LCD control pins are connected to the GPIO pins on the Arduino. If desired,
control of the LCD can be taken over by the Arduino Nano Board.
Relevant pin connections for bus communication and LCD are outlined in table # below:
Function – PIC – Arduino
LCD RS – RD2 – D4
LCD E – RD3 – D5
LCD D4 – RD4 – D6
LCD D5 – RD5 – D7
LCD D6 – RD6 – D8

Function – PIC – Arduino
LCD D7 – RD7 – D9
I2C SCL – RC3 – A5
I2C SDA – RC4 – A4
UART A->P – RC6 – D1
UART P->A – RC7 – D0

Function – PIC – Arduino
SPI SCK
– RC4 – D13
SPI D0/MOSI – RC5 – D11
SPI DI/MISO – RC4 – D12
SPI SS/CS – RE2 – D10

Microcontroller Board V4 User Manual
Note: RC3 and RC4 on the PIC are shared by both SPI and I2C modules, while the ATmega
chip used by the Arduino have separate pins for these two functions.

Programming and Software
Overview
There is no specific programming software supplied with the microcontroller board. The
onboard programmer is compatible with all MPLABX® and MPLAB® programming tools as
a PICkit™ 3 Debugger/Programmer. The onboard programmer supports all PICs devices
supported by the official PICkit™ 3 programmer.
Quick start and full user guides for MPLABX® IDE and MPLABX® IPE can be found from the
official Microchip website. The links included below will help you get access to these files
and get started promptly:

PICkit™ 3 In-Circuit Debugger/Programmer User’s Guide For MPLAB® X IDE:
http://ww1.microchip.com/downloads/en/DeviceDoc/52116A.pdf

Integrated Programming Environment (IPE) User’s Guide:
http://ww1.microchip.com/downloads/en/DeviceDoc/50002227A.pdf

MPLAB® X IDE User’s Guide:
http://ww1.microchip.com/downloads/en/DeviceDoc/50002027D.pdf

Microcontroller Board V4 User Manual

Using the Onboard Programmer

Figure 18: MPLABX® IPE Application

For those without prior experience with PIC programming software, the following steps
can generally be used to load the HEX code onto the device using the MPLABX® IPE:
1. Connect the Development Board to the PC.
2. Flip the programming switch to PRG mode and flip the power switch to ON.
3. Select the correct Family and Device from the drop down menu. For example, If the
PIC18F4620 device is used, select: Advanced 8-bit MCUs (PIC 18), PIC18F4620
4. The programmer should be detected and will be displayed as a PICkit™ 3 programmer
in the tool section.
5. Click “Connect” to connect to the programmer.
6. Wait for any firmware update (if applicable) to download and install.
7. Go to File Import Hex to load a HEX file.
© Personal Mechatronics Lab, 2016

Microcontroller Board V4 User Manual
8. Press the Program button to load the HEX file to the PIC device. The IPE will indicate
if programming is successful or if any error occurred.
9. The IPE will sometimes caution user to check if the device is truly a 5V device, this is
normal. Since the PICkit™ 3 may cause damage to a low voltage devices if the
programmer uses 5V on its I/O pins.
Note, if the Development board is disconnected at any point, it must be reconnected to
the application by pressing the “Connect” button before programming.
If any errors occur or the application cannot find the programmer or the PIC device, make
sure the programming switch is in PRG mode, turn off the power to reset the board, and
try again.
The following is a description of the common operations that may be performed within
the MPLABX IPE.
Program downloads the currently loaded HEX code into the target device.
Erase performs a bulk erase of the device, effectively returning it to its factory state. In
some cases, this may fix a device that appears faulty.
Read is used to read the current program loaded into the target PIC device. This program
can be retrieved and stored in a HEX file. It also retrieves the EEPROM data stored in the
PIC. Note that the option to save the HEX file will not be available until it is enabled from
advanced mode. For more detail on usage of the advanced mode, see MPLABX IPE User
Manual, Section 2.5.
Verify reads the contents of the PIC device and compares it against the loaded HEX file. If
any differences are observed, an error is given and the operation fails.
Blank Check is used to verify that the chip is indeed ‘blank’; this is useful after performing
an Erase Chip operation to verify that the operation succeeded.

Microcontroller Board V4 User Manual

Sample Codes
The development board package is accompanied with 10 sets of sample codes that
demonstrate functionality of the PIC as well as onboard modules. The sample codes are
written in C for the MPLAB® XC8 compiler. Microchip have been dropping support for
assembly language programming, the sample code packages uses the latest supported
platform in ensure compatibility for the future. For an official guide on the MPLAB® XC8
compiler, refer to the links below:
MPLAB® XC8 Getting Started Guide:
http://ww1.microchip.com/downloads/en/DeviceDoc/50002173A.pdf
MPLAB® XC8 C Compiler User’s Guide:
http://ww1.microchip.com/downloads/en/DeviceDoc/50002053G.pdf
Note: The XC8 Compiler is not included as part of the MPLABX® IDE package and must be
downloaded and installed separately after the MPLABX® IDE.

PIC18F4620 Samples:
All sample codes below neither uses a 10MHz external crystal oscillator or the internal
oscillator block. Refer to the description text file provided with each sample project for
the modules utilized and oscillator block used.
ADC

This is a project designed to demonstrate the Analog to Digital
conversion features of the PIC18 device. It reads the voltage input
on RA2 and RA3 and displays the 10-bit value on the LCD in
hexadecimal form.

Board_Test

This is a project that testes RTC, Keypad, LCD and Debug modules
of the development board. This project was used to test the
development board after assembly.

I2C_Arduino

This project demonstrates the I2C and Arduino board interface
features of the board. The PIC device communicates with the
Arduino Nano board and send the character pressed on the keypad
to a PC connected to the Arduino board. Additionally, when the A
key is pressed 3 times in a row on the keypad, the LCD will turn to
display characters sent to the Arduino board over Serial (9600
baud, 8-bit, no parity).

Microcontroller Board V4 User Manual
I2C_RTC

This project demonstrates the code necessary to interface with the
DS1307 real-time clock IC on the Microcontroller board, using the
I2C module of the main PIC device. The RTC time is set at the
beginning and the time kept by the RTC chip is then displayed on
the onboard LCD.

LCD

This project displays a message on the LCD upon startup of the PIC.
The LCD library may be useful to the user.

Keypad_LCD

This project demonstrates the basics of interfacing with the Keypad
and LCD modules of the Microcontroller board; anything that is
typed on the keypad is immediately displayed on the LCD.

Keypad_Interrupt

This project demonstrates usage of interrupt for keypad inputs. The
LCD displays the last key pressed on the keypad while the PIC
executes command in an infinite loop. The keypad input is handled
as an interrupt and not polled.

Port_Test

This project is a simple test program, which can be used to quickly
verify MPLABX and the programmer module are functioning
correctly. If this program executes correctly, then each of the
Debug LED’s should flash sequentially when the board is placed in
RUN mode. Note that RA4 on PIC16 devices will not turn on unless
pulled up by either a debug switch or an external resistor, since it
is an open-drain output.

PWM

This project tests the PWM module of the PIC18F4620. It generates
a 50kHz PWM signal with varying duty cycle. The signal is output
through the CCP1 pin (RC2). When running, the RC2 debug LED
should gradually increase in brightness before turning dark.

Keypad_Firmware

This project demonstrates reading and encoding of a 4x4 matrix
keypad. This code is used on the keypad encoder PIC to encode the
raw 8 pin keypad input into 5 pins for the main PIC. This code also
demonstrates internal oscillator usage of the PIC18F2550.

Microcontroller Board V4 User Manual

More Advanced Operations
Using the Board as a Standalone Programmer
The onboard programmer on the development
board have been designed with the capability to
program external PIC devices though the ICSP
interface. The ICSP interface is common for all PIC
devices all the way from PIC10 to PIC32. The Pin-out
of this header from right to left is shown in Table 3:
Figure 19: ICSP_EXT header

Pin #
1
2
3
4
5
6

Function
VPP/MCLR
VDD (VCC)
VSS (GND)
ICSPDAT/PGD
ICSPCLK/PGC
ICSOLVP/PGM

There is no need to remove the PIC device installed
on the development board, however the
Program/Run switch must be switch to the RUN
position to isolate the onboard PIC from the
programmer before the programmer can be used as
a standalone programmer.

To use the programmer externally, first turn off the
board, and connect the ICSP interface to the target
Table 3 ICSP Pins
device when the board is turned off. Then, turn on power to the
development board, ensuring that the PROG/RUN switch remains the in
the RUN position throughout the operation. Plug in the USB cable and use the
programmer as you would the same way for programming a PIC normally, with the
exception to never move the switch to PRG position.
Note: The onboard programmer has input protection on each of the programming data
pins, the ICSP pins will become inoperable for some time if a large amount of current is
sourced or sunk from it. If the programmer is failing to detect the device despite proper
setting of the program/run switch, turn off the board and let it rest for a minute or so
before attempting to program again.

Microcontroller Board V4 User Manual

Activating the Programmer-To-Go Feature
The onboard programmer does not have a pushbutton to activate
the Programmer-To-Go feature that is part of the PICkit™ 3
programmer. However, all other hardware required for
Programmer-To-Go are all present as part of the programmer, so the
feature can still be accessed if the user requires it. To simulate the
push button operation, take a fine tipped conductor, such as a
jumper cable, connect one end of the cable to GND and touch the
other end of the cable to the open solder pad on the top side of R85
Figure 20: Position
(situated just under and to the right of the PIC24 chip). This will be
of R85
recognized by the PICkit™ 3 as a button push. This action is not
recommended by the end user as the board is not designed for this operation and it is
easy to make mistakes and short other pins to ground. The procedure for loading code
into the PICkit™ 3 for Programmer-To-Go is not covered here.

Re-imaging Firmware for the Onboard Programmer
The development board is fully programmed and ready to use
out of the box. However, it has been observed in previous
iterations of this development board that many users
experienced firmware faults on the programmer that
required the programmer firmware to be re-imaged.
To reimage the programmer PIC, plug in an external PICkit 3
programmer (PICkit 2 support for PIC24FJ parts are not very
reliable) to the ICSP_PK3 header on the very top of the
Figure 21: Position of
programmer module. The pins of the ICSP header are
ICSP_PK3
arranged such that pin 6 is on the very left edge, and pin 1 is
on the right most corner. When a PICkit 3 is used, the white tringle making on the PICkit
3 body indicates pin 1 of the ICSP interface. When inserted, the indicator LEDs should face
toward the rest of the board.
The firmware file is provided as part of the sample code package along with the
development board, inside the “Production Firmware” folder. It is named
“DB4_PK3_24FJ256GB106_Firmware.hex”.
To reimage the programmer, follow the below procedures:
1. Open MPLABX Independent Programming Environment (IPE)
2. Connect PICKit3 Programmer to the computer
3. Select 16-bit MCUs (PIC24) in the Family dropdown menu
4. Select PIC24FJ256GB106 in the device dropdown menu

Microcontroller Board V4 User Manual
5. The IPE should have detected the PICKit3 programmer, click connect to connect
to the programmer.
6. Wait for the IPE to download and update firmware for the PICKit3. Reconnect to
the programmer if the procedure interrupts itself. (This will take some time)
7. Click File -> Import -> Hex. Navigate to and select the file
“DB4_PK3_24FJ256GB106_Firmware.hex” to load it.
8. Ensure the board being reprogrammed is powered on, and the program/run
switch is in the “RUN” position.
9. Click “Program” on the main interface, and wait for programming to finish.
10. The programmer firmware should now be restored to their default firmware.
To verify the programmer firmware have been correctly loaded, detach the programmer
and cycle power on the board just programmed. The 3 indicators LEDs should all light up
when the board is first powered, and after approximately 5 seconds, the 2 status LED will
extinguish, leaving only the red active LED illuminated. If this behavior is observed, the
programmer is properly loaded and functioning correctly.

Re-imaging Firmware for the Keypad Encoder PIC
Reimaging procedure for the Keypad Encoder PIC is very similar to the reimaging
procedure for the programmer. The ICSP header for the Co-Processor can be found just
to the left of the PIC18F2550 chip on the keypad module. The firmware for the PIC
encoder chip can be found as one of the sample projects, or alternatively as
“DB4_KeypadEnc_18F2550_Firmware.hex” inside the “Production Firmware” folder.

Microcontroller Board V4 User Manual

APPENDIX 1: List of all Removable Parts
The following table contains all the removable parts from the development board and
their respective part numbers.
Part

Description

Part number (Digi-Key)

DS1307 RTC Chip

DS1307 RTC chip

DS1307+-ND

Jumper Links RTC x2

Short jumpers, for JP6 and JP7, without grip

S9001-ND

Rectifier 2W04G

4pin, cylindrical

2W04G-E4/51GI-ND

Fuse Cylindrical, Series 373

Red cylindrical fuse. Ensure Series number is 373

WK3050BK-ND

Crystal 10MHZ

10MHZ crystal, primary oscillator, 20pF

CTX1058-ND

Crystal Jumpers x2

Jumper links for JP8 and JP9, with grip

S9341-ND

PIC18F4620, 40Pin package

Large (40Pin) PIC18F420 chip

PIC18F4620-I/P-ND

Keypad Buffer 74HC4066 x2

14pin, 74HC4066 chips

296-14533-5-ND

Keypad Encoder PIC18F2550

Small (28Pin) PIC18F2550 chip

PIC18F2550-I/SP-ND

Debug Buffers x4

20Pin, 74HC244 Buffer Chip

296-1582-5-ND

Keypad

4x4 keypad

GH5004-ND

LCD

LCD display 16x2 or 40x2

NHD-0216BZ-RN-YBW-ND

RTC Battery CR2032

Coin cell battery for the RTC, CR2032

SY189-ND

Note: The part numbers included are for reference only, and the parts installed on the
board might not be the exact part listed by Digi key.

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