Waveshare Compute Module IO Board Plus User manual

Compute Module IO Board Plus User Manual
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Version：V1.0，Date：20171101
Compute Module IO Board Plus
User Manual
OVERVIEW S
⚫This is an Expansion board of Raspberry Pi Compute Module series. It is compatible with
Compute Module IO Board V3 from Raspberry Pi Foundation, along with various
common use components. Supports Compute Module 3, Compute Module 3 Lite,
Compute Module 3+ (8G/16G/32G), Compute Module 3+ Lite.
FEATURES
⚫Compatible with the Compute Module IO Board V3 from the Raspberry Pi Foundation
⚫Raspberry Pi GPIO header, for connecting sorts of Raspberry Pi HATs
⚫Arduino connectivity, also supports Arduino shields
⚫1-WIRE interface, for connecting single-bus devices like DS18B20
⚫4x keys, 4x LEDs, 1x Buzzer, for I/O testing
⚫Onboard USB HUB, allows connecting more USB devices
⚫IR receiver, IR remote control is available
⚫Onboard USB TO UART, for serial debugging
⚫Sensor interface
⚫10-bit ADC, 38KSPS, 11-ch (6-ch for Arduino interface, 5-ch for sensors)
⚫16-bit DAC, 2-ch
⚫Onboard RTC, one of the most common and useful functions
WHAT’S ONBOARD

Compute Module IO Board Plus User Manual
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Version：V1.0，Date：20171101
1. Compute Module interface: for
connecting Compute Module 3,
Compute Module 3 Lite, Compute
Module 3+ (8G/16G/32G) or Compute
Module 3+ Lite
2. Compute Module GPIO header:
breakout all the Compute Module pins
3. Raspberry Pi GPIO header: for
connecting Raspberry Pi HATs
4. CSI interface: camera ports, for
connecting Raspberry Pi Camera
5. DSI interface: display ports, for
connecting Raspberry Pi LCD
6. HDMI port
7. USB ports: for connecting USB
devices
8. USB SLAVE interface: allows you to
burn system image in to Compute
Module 3
9. USB TO UART interface: for serial
debugging
10. Arduino header: for connecting
Arduino shields
11. AD/DA input/output screw terminals
12. 1-WIRE interface: for connecting
single-bus devices like DS18B20
13. Sensor interface

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14. Power port: 5V 2.5A
15. FE1.1S: USB HUB chip
16. 12MHz crystal
17. CP2102: USB TO UART converter
18. Micro SD card slot: insert a Micro SD
card with pre-burnt system, to start up
Compute Module 3 Lite
19. TLC1543: AD converter
20. DAC8552: 16-bit DAC, 2-ch
21. DS3231: high-precision RTC chip, I2C
interface
22. RTC battery holder: supports CR1220
batteries
23. Voltage regulator: 3.3V / 2.5V / 1.8V
24. LFN0038K: IR receiver
25. Buzzer
26. Power indicator
27. ACT indicator: indicating the Micro SD
card status
28. User LEDs
29. User Keys
30. BOOT selection
- EN: enable the PC to access SD
card/eMMC through USB SLAVE
- DIS: the Compute Module will boot
from SD card/eMMC
31. VGx power selection: config the I/O
level
32. USB HUB enable jumper: HUB
enable and USB SLAVE power
selection
33. ADC/DAC configuration: config the
power supply and reference voltage of
ADC/DAC
34. Peripheral configuration: config the
control pins of UART, user keys, user
LEDs, 1-WIRE interface, IR receiver,
and buzzer
35. Arduino AD selection
- connect 1 and 2: Arduino A0-A5 as
digital control pin
- connect 2 and 3: Arduino A0-A5 as
AD input

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CONTENTS
OverViews ................................................................................................................................1
Features ............................................................................................................................1
What’s OnBoard ................................................................................................................1
HOW TO USE ..........................................................................................................................7
INSTALLATION.................................................................................................................7
CM3/CM3+ .................................................................................................................7
CM3L/CM3+ L ............................................................................................................7
Connecting display and Camera .......................................................................................8
Connecting the officail 7inch display ..........................................................................8
Connect Wveshare 7inch HDMI LCD (C) ...................................................................8
Connect Camera ........................................................................................................8
Examples................................................................................................................................10
Buzzer .............................................................................................................................10
pyhton code..............................................................................................................10
WiringPi code ...........................................................................................................10
Expected result ........................................................................................................11
DAC.................................................................................................................................11
BCM2835 code ........................................................................................................11
Expected result ........................................................................................................11
DS18B20 .........................................................................................................................11
sysfs code ................................................................................................................11
python code..............................................................................................................12

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Expected result ........................................................................................................12
RTC DS3231 ...................................................................................................................12
BCM2835 code ........................................................................................................12
WiringPi code ...........................................................................................................12
Python code .............................................................................................................12
Expected result ........................................................................................................13
IRM..................................................................................................................................13
BCM2835 code ........................................................................................................13
WiringPi code ...........................................................................................................13
Python code .............................................................................................................13
Expected result ........................................................................................................14
KEY .................................................................................................................................14
BCM2835 code ........................................................................................................14
WiringPi code ...........................................................................................................14
Python code .............................................................................................................14
Expected result ........................................................................................................14
LED .................................................................................................................................14
BCM2835 code ........................................................................................................15
WiringPi code ...........................................................................................................15
Python code .............................................................................................................15
Expected result ........................................................................................................15
ADC.................................................................................................................................15
BCM2835 code ........................................................................................................15

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WiringPi code ...........................................................................................................16
Python code .............................................................................................................16
Expected result ........................................................................................................16
UART...............................................................................................................................16
WiringPi code ...........................................................................................................16
Python code .............................................................................................................17
Expected result ........................................................................................................17

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HOW TO USE
INSTALLATION
CM3/CM3+
If you use Compute Module 3 or Compute Module 3+, you need to write OS image to the
embedded EMMC, otherwise they cannot work. Here show you how to write image to EMMC
1. Pull the jumpers of USB SLAVE 1/2/3/4 SELECTION (you need to pull two jumpers
here), set the BOOT ENABLE USB SLAVE jumpers to EN position.
2. Install USB driver. Run the software rpiboot_setup (You can download it from Resource
of wiki) to install the drivers and boot tool.
3. Connect 5V power adapter to Power interface, plug the USB SLAVE port of IO Board
Plus into your host PC USB.
4. Run the rpiboot.exe tool. After a few seconds, the CM3 eMMC will be recognized as a
disk.
5. Run WinDiskImager.exe tool to burn the image to eMMC of CM3.
Note:
Ensure you are not writing to any USB devices while installation.
Because the eMMC of CM3 is only 4G, the image file flashed should be small than 4G. If you
want the GUI, you can install it with these commands after installation
sudo apt-get update
sudo apt-get install raspberrypi-ui-mods
CM3L/CM3+ L
1. Download the image for CM3L
2. Connect the SD card to computer with card reader. The capacity of SD card should
larger than 8G.
3. Run the Win32DiskImager.exe, choose the CM3L image and burn it to SD card.
4. After burning successfully, insert the card to the card slot of IO Board Plus

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CONNECTING DISPLAY AND CAMERA
Download the test image provide by us and install them.
Note: Before using, please check that whether the BOOT ENABLE USB SLAVE jumper is set
onto the DIS option.
CONNECTING THE OFFICAIL 7INCH DISPLAY
1. You need an adapter plate and a 22PIN FFC to connect the display to DISP1 interface of
IO Board Plus
2. Connect the 5V and GND pin of display to 5V and GND pin of IO Board Plus with wires.
3. Connect these pins together with wires:
GPIO0<->CD1_SDA
GPIO1<->CD1_SCL
4. Connect the power adapter
5. Wait for a few seconds, the display will be powered on.
CONNECT W VESHARE 7IN CH HDMI LCD (C)
1. Make sure the official 7inch display don’t be connect to IO Board Plus. Only without the
DISP interface display, the Raspbian will display via HDMI interface by default.
2. Connect the HDMI interface of LCD to the HDMI interface of IO Board IO Plus
3. Connect power adapter
4. Waiting for a few seconds, the LCD will be powered on
CONNECT CAMERA
1. Connect camera to the CAM1 interface of IO Board Plus (need RPi Zero V1.3 Camera
Cable 15cm)
2. Connect these pins together:
GPIO0<->CD1_SDA

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GPIO1<->CD1_SCL
GPIO4<->CAM1_IO1
GPIO5<->CAM1_IO0
3. Connect to power
4. If you want to connect more than one camera, you can connect another to CAM0
interface.
5. Use the CAM0 interface, you need to connect these pins together:
GPIO28<->CD0_SDA
GPIO29<->CD0_SCL
GPIO30<->CAM0_IO1
GPIO31<->CAM0_IO0
6. Execute these commands to use the camera:
raspivid -t 0 -cs 0
raspivid -t 0 -cs 1
Note:
1. -cs: Used to choose the camera 0 or 1. Parameter 0 means CAM1, and 1 means CAM0
2. Original Raspbian has no boot files for official display and official. If you use original
Raspbian, you need to convert dts files which are provided by Raspberry Pi to bin files
and copy the bin files to pi/boot/ of Raspbian.
Commands:
sudo dtc -I dts -O dtb -o /boot/dt-blob.bin dt-blob-disp1-cam2.dts
If you use the image provide by us, the OS has been pre-configured. You need to
configure it again.

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EXAMPLES
While test the examples, you had better connect a display and keyboard to the IO Board Plus.
If you use original Raspbian, you have to install necessary libraries before first. For more
information about how to install libraries, please refer to Libraries Installation for RPi.
BUZZER
PYHTON CODE
⚫Execute command to enter the folder of program:
cd /home/pi/CM3/Buzzer_PWM/python/
⚫Execute command to run the program:
sudo ./buzzer.py
WIRINGPI CODE