This Mini Base Board (B) for the Raspberry Pi Compute Module 4 is a compact CM4 breakout option offering a good set of features with a small footprint.

Two versions of this board are available - Lite (A) or Full (B). This is the Full (B) version which comes with the additional Real-time Clock (RTC) and fan speed control.

With its M.2 slot, MicroSD card slot, Real-Time Clock, dual-CSI ports for camera modules and a host of other features, it's a great base for any CM4 project you're planning.

Note: Compute Module, M.2 SSD and RTC battery not included

Features

The CM4 Mini base board offers the following connectivity options and features:

40-pin Raspberry Pi GPIO header
1x RJ45 Gigabit Ethernet
2x USB 2.0 ports
1x Full-size HDMI port
1x M.2 slot (Supports NVME SSD or communication modules with PCI-E M.2 KEY-M interface)
1x MicroSD slot
1x Real-Time Clock (RTC) (battery not included)
2x CSI Camera ports
1x DSI Display port
1x USB 2.0 FFC Connector
1x HDMI FFC Connector
1x 4-pin fan header
USB-C programming/power port

Mini Base Board B for CM4 features 1

Specification

POE	N/A
USB	USB 2.0 × 2
USB	USB 2.0 × 2 (via FFC connector)
GPIO	Raspberry Pi 40PIN GPIO × 1
HEADER	M.2 slot × 1


HDMI	HDMI × 2
	(1x via FFC connector)
	Supports 4K 30fps output
DSI DISPLAY	MIPI DSI × 1
DSI DISPLAY	(15pin 1.0mm FPC)
CSI CAMERA	MIPI CSI-2 × 2
CSI CAMERA	(15pin 1.0mm FPC)
POWER INPUT	5V
FAN	5V
FAN	Allows speed adjustment and measurement
RTC	Real-time clock with battery socket and ability to wake Compute Module 4
RJ45 ETHERNET	Gigabit Ethernet
CM4 SOCKET	Suitable for all variants of Compute Module 4
SD CARD SLOT	MicroSD card socket for Compute Module 4 Lite (without eMMC) variants
DIMENSIONS (MM)	85.0 × 56.0

What's Onboard

Mini Base Board for CM4 components

1) CM4 socket
- Suitable for all variants of Compute Module 4
2) Power input/Programming
- 5V/2.5A power supply, or used for eMMC burning
3) DISP
- MIPI DSI display port
4) Fan
- For connecting cooling fan, allows speed adjustment and measurement
5) Camera
- 2x MIPI CSI camera ports
6) HDMI0 connector
- HDMI0 port, supports 4K 30fps output
7) USB 2.0 ports
- 2x USB 2.0 ports, for connecting USB devices
8) Gigabit Ethernet connector
- Gigabit Ethernet RJ45 connector, with 10 / 100 / 1000M network support
9) M.2 indicator
- Indicating the operating status of M.2 interface
10) ACT indicator
- Indicating the operating status of Raspberry Pi
11) PWR indicator
- Indicating the status of Raspberry Pi power supply
12) BOOT selection
- ON: CM4 would be booted from USB-C interface
- OFF: CM4 would be booted from eMMC or Micro SD card
13) 40-pin GPIO header
14) Micro SD card slot
- For connecting a Micro SD card with pre-burnt image (Lite variant ONLY)
15) HDMI1 FFC connector
- HDMI1 port, supports 4K 30fps output
16) USB 2.0 FFC connector
- Can be connected through an adapter
17) FE1.1S
- USB HUB chip, expanding one USB port to 4x ports
18) M.2 slot
- Supports NVME SSD, or communication modules with PCI-E M.2 KEY-M interface
19) RTC chip
- Allows RTC-related functions like wakeup, shutdown, reboot, and more
20) RTC interrupt selection
- PI-RUN: CM4 reboot on RTC interruption
- GN-EN: CM4 shutdown on RTC interruption
- D4: D4 pin is triggered on RTC interruption
21) EMC2301
- Fan controller, for speed adjustment/measurement
22) RTC battery holder
- Supports CR1220 button cell

Resources

Product Wiki

Package Contents

1x CM4 Mini Base Board (B)
1x SSD Mounting Screw

Compute Module, M.2 SSD and RTC battery not included

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