Compute Module 4 PoE Board (B)
The Compute Module 4 PoE 4G Board is an industrial-grade IO baseboard designed for Raspberry Pi Compute Module 4 (not included). It is a baseboard that can be used with Raspberry Pi Compute Module 4, and supports PoE power supply and 5V DC power supply, and has four USB2.0 onboard, which is convenient for users to use.
Precautions for use
1: Do not plug and unplug any device except USB and HDMI while the baseboard is working.
2: Please confirm the fan voltage before connecting. It supports 5V and 12V. The default connection is 5V. Please modify the jumper of FAN_VCC if you want to switch the fan voltage
3: Type C interface can be used for power supply or USB SLAVE interface for burning image.
4: In order to ensure the normal power supply of CM4, please do not connect other devices when using the Type C interface to burn the image.
5: When CM4 is in normal use, it needs to provide 5V 2A power supply for CM4. Otherwise, problems such as automatic shutdown, frequency reduction, etc. may occur.
6: USB2.0 is closed by default, if you need to open it, you need to add dtoverlay=dwc2,dr_mode=host in the config.txt.
7: When using the PoE function, pay attention to check whether the switch supports PoE of the 802.3af network standard.
8: When you need to use POE, connect the POE jumper cap to the EN position.
9: Two DISP interfaces cannot be used together by default.
What's on board
|1||CM4 socket||Suitable for all variants of Compute Module 4|
|2||40PIN GPIO header||~|
|3||BOOT selection||ON: CM4 would be booted from USB-C interface |
OFF: CM4 would be booted from eMMC or Micro SD card
|4||Misc functional pins||~|
|5||USB Type-C power supply / programming||5V/2.5A power supply,|
also allows burning system image into Compute Module 4 eMMC variants
|6||Status indicators||ACT: Raspberry Pi operating status indicator|
PWR: Raspberry Pi power indicator
|7||DISP||2x MIPI DSI display port|
|8||CAM||2x MIPI CSI camera connectors.|
|9||USB2.0 ports||4x USB2.0 ports, for connecting sorts of USB devices|
|10||HDMI ports||2x HDMI ports, supports dual 4K 30fps output|
|11||RTC battery holder||supports CR1220 button cell|
|12||FAN header||for connecting cooling fan, allows speed adjustment and measurement|
|13||PCIe Gen 2 × 1 socket||forconnecting PCIe Gen 2 × 1 modules|
|14||Gigabit Ethernet connector||Gigabit Ethernet RJ45 with PoE support, 10/100/1000M compatible|
|15||DC 5V output||~|
|16||RS485||with 600W lightning-proof, anti-surge, and 15KV ESD protection,|
reversed optional 120R balancing resistor jumper
|17||RS232||with TVS diode, anti-surge, and ESD protection|
|19||FAN_VDD/PoE selection||cooling fan driving voltage: 12V or 5V|
PoE: enable (EN) or disable (DIS)
|20||FE1.1S||USB expansion chip|
|22||RTC/FAN||I2C bus switch,|
SDA0/SCL0: I2C-10 is shared with CSI/DSI
GPIO3/2: I2C-1 is shared with 40PIN header
|23||IO logic level selection||set the CM4 IO logic level as 3.3V or 1.8V|
|24||RTC interruption configuration||PI-RUN: CM4 will reboot on RTC interruption|
GN-EN: CM4 powerdown on RTC interruption
D4: D4 pin is triggered on RTC interruption
|25||Micro SD card slot||insert a Micro SD card with pre-burnt system, to start up Compute Module 4 Lite|
Special function pin description
|1||PI BOOT||Don't use it, use the BOOT DIP switch|
|2||EEPROM WP||Low level prevents EEPROM from being rewritten|
|3||IP1/0||CM4 motherboard MXL7704 AN1/0 pin|
|4||VADC COMP||Composite video output|
|5||ETH IN||ETH sync signal|
|6||PI_EN||is synchronized with PI_RUN signal|
|7||PI_GLOBAL_EN||CM4 onboard MXL7704 power enable pin, low level disable|
|8||PI_RUN||CM4 status indication, high level means it is powered on, forcibly pull down to force restart CM4|
|9||WIFI_EN||WIFI enable, disable at low level, open when suspended|
|11||BT_EN||Bluetooth enable, disable at low level, enable when floating|
Do not plug or unplug any device while it is powered on
- Write Image for Compute Module Boards eMMC version
- Wrote Image for Compute Module Boards Lite version
It is closed by default. If you need to open it, you need to add content in config.txt:
sudo nano /boot/config.txt
RS232 occupies GPIO5/GPIO4 (BCM code 4/5), device number ttyAMA1
RS485 occupies GPIO13/GPIO12 (BCM code 13/12), device number ttyAMA2
Note: There is an RS485 serial port switch on the back, which can be switched to GPIO14/GPIO15.
The USB interfaces are default disabled in CM4, you need to enable it by adding the following lines:the config.txt
It will take effect after restart
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)
- 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, that is, the fan control chip has been powered on, otherwise the chip will be burned!
- Note: Please confirm the fan voltage and the actual connected fan power supply before connecting
Note that if you want to use the RTC function, please first disable the DSI and CSI. And I2C-10 is used by default
RTC (PCF85063a) on i2c-10, address is 0x51 (7-bit address)
FAN (EMC2301) on i2c-10, address is 0x2f (7-bit address)
If you need simple use, or need to add to your program instead of the kernel, see C and Python routines.[CM4 RTC FAN]
Open the terminal and modify the config.txt file
sudo nano /boot/config.txt
Add the following lines to the file and modify the audio setting
#Add the lines to the end of file dtparam=i2c_vc=on dtoverlay=i2c-rtc,pcf85063a,i2c_csi_dsi #remove the setting dtparam=audio=on by adding the # to the front of the line #dtparam=audio=on
Save and reboot the Raspberry Pi
Synchronize system clock -> hardware clock
sudo hwclock -w
Synchronize hardware clock -> system clock
sudo hwclock -s
Note that you need to disable the network synchronization function, otherwise the time will be changed according to network time.
Set hardware clock：
sudo hwclock --set --date="9/8/2021 16:45:05"
Check the hardware clock
sudo hwclock -r
Check the version.
sudo hwclock --verbose
When powered on, the fan will spin for 1 second, then stop for 2 seconds, and then spin again, this is a normal phenomenon
There is currently no official configuration method for fans, there is a third-party configuration method: https://github.com/neg2led/cm4io-fan
This method is released by a third party, not an official release, and we are not responsible for any problems!
mkdir -p ~/src cd ~/src git clone https://github.com/neg2led/cm4io-fan.git cd cm4io-fan sudo chmod 777 install.sh sudo ./install.sh
The device tree overlay has a few options, here's the equivalent of a /boot/overlays/README info section:
############################# Name: cm4io-fan Info: Raspberry Pi Compute Module 4 IO Board fan controller Load: dtoverlay=cm4io-fan,<param>[=<val>] Params: minrpm RPM target for the fan when the SoC is below mintemp (default 3500) maxrpm RPM target for the fan when the SoC is above maxtemp (default 5500) midtemp Temperature (in millicelcius) at which the fan begins to speed up (default 50000) midtemp_hyst Temperature delta (in millicelcius) below mintemp at which the fan will drop to minrpm (default 2000) maxtemp Temperature (in millicelcius) at which the fan will be held at maxrpm (default 70000) maxtemp_hyst Temperature delta (in millicelcius) below maxtemp at which the fan begins to slow down (default 2000) #############################
For examples, speed up the fan if the temperature is higher than 45°C and set the it to maximum value if the temperate is higher than 50°C:
CSI and DSI interfaces are closed by default, they will use the I2C-10, I2C-11 and I2C-0.
Open a terminal and run the following commands:
wget https://www.waveshare.net/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/ #If using two cameras and DSI0 execute sudo dtc -I dts -O dtb -o /boot/dt-blob.bin dt-blob-disp0-double_cam.dts # if using two cameras and DSI1 execute sudo dtc -I dts -O dtb -o /boot/dt-blob.bin dt-blob-disp1-double_cam.dts #When using any DSI, HDMI1 has no image output, even if you do not connect the DSI screen, as long as the corresponding file is compiled, then HDMI1 will not output #If you need to restore, delete the corresponding dt-blob.bin: sudo rm -rf /boot/dt-blob.bin # After execution, turn off the power and restart the CM4
Then connect the Camera and DSI display:
1: Make sure the connection is in the power-off state
2: Connect Power
3: Wait a few seconds for the screen to start up
4: If it fails to start, check whether /boot/dt-blob.bin exists, and restart it if it exists.
5: 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.
Old version (Buster)
Test the Raspberry Pi camera
Check the first camera connected to the screen:
sudo raspivid -t 0 -cs 0
Check the second camera connected to the screen：
sudo raspivid -t 0 -cs 1
If using the latest Raspberry Pi OS (Bullseye):
libcamera-hello -t 0 or libcamera-hello #The new system uses dual cameras #Remove camera_auto_detect=1 in config.txt #camera_auto_detect=1 #Add to dtoverlay=imx219,cam1 dtoverlay=imx219,cam0 #where imx219 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 #Other part of the command: #Check if the camera is detected libcamera-hello --list-cameras #Open the corresponding camera libcamera-hello --camera 1 libcamera-hello --camera 0 #Taking Pictures libcamera-jpeg -o test.jpg #You can add --camera to specify the camera
More instructions click me
- Note: If using the DSI interface display will have an HDMI disabled, even if just compile the corresponding file without connecting the DSI screen.
- Any connection of two HDMIs can output images, not limited to that HDMI, if two HDMI screens are connected, only HDMI0 has image output
- If you want to enable both HDMI, delete the dt-blob.bin file with the following command:
sudo rm -rf /boot/dt-blob.bin
- Then reboot
Reference Raspberry Pi Manual
- Raspberry Pi Compute Module 4 IO Board Brief
- Raspberry Pi Compute Module 4 IO Board Datasheet
- CSI Camera Reference
- DSI Display Reference
a) Check whether dtparam -audio - on
is blocked in /boot/config.txt