Template: Compute Module 4 PoE Board B Spec

Overview

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, 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 the power supply or a USB SLAVE interface for burning images.
4: 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 checking whether the switch supports the 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.

Dimension

Compute_Module 4 POE Board (B)

Compute_Module 4

What's on board

No.	Component	Description
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
18	Buzzer	~
19	FAN_VDD/PoE selection	cooling fan driving voltage: 12V or 5V PoE: enable (EN) or disable (DIS)
20	FE1.1S	USB expansion chip
21	PCF52063ATL	RTC 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-programmed system, to start up Compute Module 4 Lite

Special function pin description

	Name	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