Template: Cm4-disp-base-7a-box Guide
- Write Image for Compute Module Boards eMMC version
- Wrote Image for Compute Module Boards Lite version
The USB port is disabled by default on the CM4 for saving power. If you need to use it, you need to add the following to the config.txt file:
Then reboot the CM4
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 workable. If you want to remove this error, please remove the line otg_mode=1 in [cm4] of config.txt, and add dtoverlay=dwc2, dr_mode=host (USB cannot be recognized without adding it).
Enable I2C Interface
Open a terminal and run the following commands：
sudo raspi-config Choose Interfacing Options -> I2C ->yes
Reboot Raspberry Pi：
- RTC: i2c-1 （0x51）
- FAN： i2c-1 (0x2F)
They are disabled by default. If you need to use the RS485 or RS232, you need to modify the config.txt:
sudo nano /boot/config.txt<br>
And add the following lines:
dtoverlay=uart3 dtoverlay=uart5 <pre> Then reboot the CM4 and check if the corresponding ports were recognized. <pre> reboot ls /dev/ttyAMA*
RS232 occupies GPIO5/GPIO4 (BCM code 4/5), device number ttyAMA1
RS485 occupies GPIO13/GPIO12 (BCM code 13/12), device number ttyAMA2
RS485 can be switched to GPIO15/14 for device number ttyS0
Refer to number 27 of the Onboard Resources, change the corresponding resistance to the corresponding position
sudo apt-get install minicom # RS232 sudo minicom -D /dev/ttyAMA1 #RS485 sudo minicom -D /dev/ttyAMA2
The GPIO input/output interface only supports a single-mode and does not support switching. The following are the corresponding pins of the interface.
OUT CH1 GPIO17
OUT CH2 GPIO27
IN CH1 GPIO22
IN CH2 GPIO23
The module only supports 3.3V and 5V, which can be switched by jumper caps.
Add the following lines to config,txt
dtparam=audio=on dtoverlay=audremap,pins_18_19 audio_pwm_mode=2 disable_audio_dither=1
Reboot the CM4 and check if the new play device is recognized by the command aplay -l
After it is turned on, it can be recognized under the audio selection. There may be a problem that the default sound card is not a GPIO sound card.
- Note: Please connect the fan before turning on the power of the expansion board and then complete the test. Please do not connect the fan after the expansion board has been powered on, otherwise the chip will be burned!
I2C-1 is used by default
RTC (PCF85063a) on i2c-1, address is 0x51 (7-bit address)
FAN (EMC2301) on i2c-1, address is 0x2f (7-bit address)
sudo nano /boot/config.txt #Add at the end dtparam=i2c_arm=on dtoverlay=i2c-rtc,pcf85063a #Save and exit, restart sudo reboot
Hwclock is simple to use
Synchronize System Clock -> Hardware Clock
sudo hwclock -w
Synchronize hardware clock -> system clock
sudo hwclock -s #The network needs to be closed, or the network pair is closed, or the clock will be changed back #This command is only for test use, please open it during actual use, the time is more accurate #Turn off network timing # sudo timedatectl set-ntp false #Enable network timing # sudo timedatectl set-ntp true
Set the hardware clock time:
sudo hwclock --set --date="9/8/2021 16:45:05"
Check hardware clock
sudo hwclock -r
Show version information
sudo hwclock --verbose
When powered on, the fan will spin for 1 second, then stop for 2 seconds, this is a normal
wget https://www.waveshare.com/w/upload/b/b9/EMC2301_i2c1_code.zip unzip -o EMC2301_i2c1_code.zip -d ./EMC2301_i2c1_code sudo chmod 777 -R EMC2301_i2c1_code cd EMC2301_i2c1_code/ #C cd c/ make sudo ./main #python cd python/examples sudo python main.py
Screen and camera turned on
If you use the buster system, you just need to add the configuration file and reboot.
If you use the new version (bullseye) system, additional modifications are required
Load Configuration File
When using the camera and DSI, it will occupy three I2C devices: I2C-10, I2C-11, I2C-0
The camera needs to run raspi-config, select Interfacing Options->Camera->Yes->Finish-Yes, reboot the system, open the enable camera, and then restart to save the changes.
Execute as follows:
wget https://www.waveshare.com/w/upload/7/75/CM4_dt_blob_Source.zip unzip -o CM4_dt_blob_Source.zip -d ./CM4_dt_blob_Source sudo chmod 777 -R CM4_dt_blob_Source cd CM4_dt_blob_Source/ sudo dtc -I dts -O dtb -o /boot/dt-blob.bin dt-blob-disp0-double_cam.dts # After execution, turn off the power and restart the CM4
Old Version (Buster)
Note: On December 2, 2021, the Raspberry Pi OS for Raspberry Pi split into two branches, the Buster branch, and the Bullseye branch.
The Buster branch is a continuation of the old system and is more stable. The Bullseye branch adds some new features, uses open source libraries and new interfaces.
If you use the Buster branch system, the image can be used normally without any modification. View the first connected camera screen:
sudo raspivid -t 0 -cs 0
New Version (Bullseye)
If you are using the Bullseye branch of the system, refer to the following
Comment the following statements in the config.txt file (the config file is located in the root directory of the TF card, namely /boot):
Add the following statement below [all]:
After saving, restart the Raspberry Pi
libcamera-hello -t 0 or libcamera-hello #The default camera model is ov5647, if you need to change it to other cameras, you can check the camera model by yourself #Add to dtoverlay=ov5647,cam1 dtoverlay=ov5647,cam0 #where ov5647 is the camera sensor model, and there are other sensors dtoverlay=ov5647,cam0 dtoverlay=imx219,cam0 dtoverlay=ov9281,cam0 dtoverlay=imx477,cam0 #then restart reboot # another part of the command: #Check if the camera is detected libcamera-hello --list-cameras #open camera libcamera-hello --camera 0 #Taking Pictures libcamera-jpeg -o test.jpg #You can add --camera to specify the camera