Template: CM4 Duino Guide

From Waveshare Wiki
Jump to: navigation, search

Writing Image


USB2.0

The USB port is disabled by default on the CM4 to save power. If you need to start, you need to add the following to the config.txt file:

 dtoverlay=dwc2,dr_mode=host

After restarting

If you use the latest Raspberry Pi OS (image after October 30, 2021) USB2.0 is OTG mode by default, CM4 will report an error:

 config failed, hub doesn't have any ports! (err -19)

However, USB can still be used. If you want to remove this error, remove otg_mode=1 in [cm4] of config.txt, and add dtoverlay=dwc2, dr_mode=host (USB cannot be recognized without adding it).
CM4 Burn EMMC 12.png


ADC

Basic introduction

The ADS7830 is a single-supply, low-power, 8-bit data acquisition device with a serial I2C interface and an 8-channel multiplexer. The analog-to-digital (A/D) converter has a track-and-hold amplifier and an internal asynchronous clock.
The ADS7830 has a resolution of 8 bits, a total of 8 inputs, and a maximum sampling rate of 70KSPS.
It can be set to differential mode and single-ended input, and the program defaults to single-ended input.
The I2C address is: 0x48

Download Program

Open the Raspberry Pi terminal and execute the following command:

sudo apt-get install p7zip-full
https://www.waveshare.net/w/upload/5/5d/CM4-duino-code.zip
7z x CM4-duino-code.zip -O./
cd CM4-duino-code

Python

Run the routine, the program supports python2/3

# python2
sudo python ADS7830.py
# python3
sudo python3 ADS7830.py

As shown in the figure below, A0-A7 are 7 analog input channels:
CM4-Duino11.png
Note: A total of 8 ADCs are collected from 0-7. If the channel is suspended, the value of the channel will float up and down, and the data will be invalid;

LED usage

A programmable LED is onboard:
CM4-Duino6.png
Using GPIO6 CM4-Duino7.png


Button usage

Onboard 2 buttons USER1 USER2:
CM4-Duino8.png
USER1 uses GPIO4, USER uses GPIO5, and USER2 can choose whether it is the reset of CM4 through the resistor, and the default connected GPIO5 CM4-Duino9.png
CM4-Duino10.png

Functional pin description

CM4-Duino-10.png

Label Name Description
1 BT-DIS Disable Bluetooth, only support core board with wireless module
2 WIFI-DIS Disable WIFI, only support core board with wireless module
3 IO-VREF IO logic voltage selection
4 RUN/GL-EN Reset or shutdown CM4
5 CFG CFG pin function select 3.3V or A6
6 USER User button Function selection, D5 or RST
7 I2C ADDR ADC function module I2C address selection, default address: 0x48

CSI DSI

CSI and DSI are disabled by default. I2C-10、I2C-11、I2C-0 should be used for Camera and DSI displays.
Open a terminal and run the following commands:

 sudo apt-get install p7zip-full
 wget https://www.waveshare.com/w/upload/4/41/CM4_dt_blob.7z
 7z x CM4_dt_blob.7z -O./CM4_dt_blob
 sudo chmod 777 -R CM4_dt_blob
 cd CM4_dt_blob/
 #If you want to use both cameras and DSI0
 sudo  dtc -I dts -O dtb -o /boot/dt-blob.bin dt-blob-disp0-double_cam.dts
 #If you want to ue both cameras and DSI1
 sudo  dtc -I dts -O dtb -o /boot/dt-blob.bin dt-blob-disp1-double_cam.dts
 #HDMI1 is disabled if you use DSI interfaces for displayin. HDMI1 cannot work even thought you just built the file without connecting DSI display, please note it.
 #If you want to enable the HDMI1, please remove the dt-blob.bin file with the command: '''sudo rm -rf /boot/dt-blob.bin'''
 #Turn off IO Board and re-power the CM4

Connect Cameras and DSI display
1: Please first disconnect power off the IP Board when connecting.
2: Use CM-DSI-ADAPTER to connect Compute Module 4 PoE Board and DSI displays
3: UseCSI adapter cable to connect Compute Module 4 PoE Board and CSI cameras.
3: Connect the power adapter
4: Wait for booting.
5: If the DSI display cannot work, please check if you have added /boot/dt-blob.bin and reboot.
6: Please enable camera by raspi-config, choose Interfacing Options->Camera->Yes->Finish-Yesand reboot

Reference:

Test RPi Camera:
Test video0:

sudo raspivid -t 0 -cs 0

Test video1:

sudo raspivid -t 0 -cs 1