WSAL19182 – Compute Module 4 POE Board/en
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Documentation notice: This technical documentation was independently rewritten from an archived supplier source. Check technical details and commands against the product version and manufacturer documentation before use.
Summary
The Waveshare Compute Module 4 PoE Board is an IO board for evaluating or integrating Raspberry Pi CM4/CM4L. It provides PoE power supply (802.3af), a 7–36 V DC input, four USB 3.2 Gen1 ports, dual HDMI, two MIPI CSI and two MIPI DSI connectors, plus RTC and PWM fan control via I2C.
Related products at JW Tech
- WSAL19182 – Raspberry Pi Compute Module 4 Dev Kit, with Waveshare PoE Board and Optional 7" Touchscreen
- WSAL19183 – Raspberry Pi Compute Module 4 Dev Kit, with Waveshare PoE Board and Optional 7" Touchscreen
Technical overview
- Power: PoE per 802.3af or 7–36 V DC; at least 5 V / 1.5 A is recommended for normal CM4 operation.
- Interfaces: 4× USB 3.2 Gen1, Gigabit Ethernet with PoE, dual HDMI (4K@30 fps), 40-pin GPIO header, and Micro-USB as USB slave for image flashing.
- MIPI: Two CSI camera ports and two DSI display ports; by default the two DISP outputs cannot be used simultaneously.
- RTC: PCF85063A on I2C-10 (address 0x51); supports wake-up, shutdown, and reboot functions.
- Fan: EMC2301 on I2C-10 (address 0x2f); supports PWM fans; only 5 V fans are supported.
- Configuration: Via /boot/config.txt or /boot/firmware/config.txt using dtoverlay lines; changes require a reboot.
- PoE activation: Set the jumper to EN; the connected switch must support 802.3af.
- Camera support: e.g. OV9281, IMX290/IMX327, IMX378, IMX219, IMX477, IMX296, IMX708 via corresponding dtoverlay lines.
Commands and examples – verify before use:
sudo nano /boot/config.txt
dtparam=i2c_vc=on
dtoverlay=i2c-rtc,pcf85063a,i2c_csi_dsi
sudo hwclock -w
sudo hwclock -s
sudo hwclock --set --date="9/8/2021 16:45:05"
sudo hwclock -r
uname -a
dtoverlay=i2c-fan,emc2301,i2c_csi_dsi,midtemp=45000,maxtemp=65000
i2cdetect -y 10
libcamera-hello --list-cameras
libcamera-hello -t 0
libcamera-jpeg -o test.jpg
libcamera-vid -t 10000 -o test.h264
sudo raspivid -t 0 -cs 0
sudo raspivid -t 0 -cs 1
Notes and version constraints
- Do not plug or unplug any device other than USB and HDMI while the baseboard is powered on.
- Only 5 V fans are supported; 12 V fans will not work.
- Micro-USB is exclusively a USB-slave interface for image flashing and cannot be used as OTG.
- Insufficient power (below 5 V / 1.5 A) may cause automatic shutdown or frequency reduction.
- Ensure the baseboard is powered off before connecting the fan, otherwise the fan-control chip may be damaged.
- Enabling a DSI display disables the HDMI1 output, even if no DSI screen is connected.
- Any change to config.txt requires a reboot to take effect.
- Kernel version must be ≥ 6.1.31 for fan control to function.
- Single cameras only operate on CAM0; CAM1 alone is not possible.
- If i2cdetect does not show a valid address, check whether dt-blob.bin exists and that dtparam audio is not blocked.
Source and revision record
- Compute Module 4 POE Board - Waveshare Wiki
- Source revision: 104443
- Captured: 2026-09-01T04:00:17+00:00
- SHA-256:
95f1875b58fe3ea5e473c81d5ae5f5b6427b1f4fe0f9c580b9d885098fe3ad2e