Small carrier board for Raspberry Pi CM4

I will describe the project and give links to download the v1.0 (RC1) files

Writing articles is not my thing, I’d rather have professionals do it:

Article on tomshardware.com (link)

Article on hackster.io (link)

A short review from Jeff Geerling:

What do we have on the board:

  • 5v (in and out)
  • 3.3v (limited by CM4)
  • GPIO 14, 15 (UART)
  • GPIO 2, 3 (I2C)
  • GPIO 18 (PWM 1)
  • GPIO 13 (PWM 2)
  • GPIO  4, 12 (Digital I/O)
  • LEDs: power and active 
  • USB-C Power Delivery

The funniest thing is the parts list, which means that only the port itself is required, and everything else is basically optional:

  • Port for CM4: Hirose DF40C-100DS-0.4V (most important apart from the PCB)
  • Capacitor C1, 667-EEF-CX0J101R (optional, recommended for thin and/or long USB power cables)
  • C2-C5 capacitors, 10uF, 0805 or 0603 (similar to previous point)
  • J1, USB-C port GCT_USB4105-GF-A (optional)
  • R1-R2, 5.1k, 0603, Resistors required for USB-C Power Delivery (optional)
  • D1-D2, 0603, LEDs (optional)
  • U1, Power LED buffer, 74LVC1G07SE-7 (optional)
  • R3-R4, 1k, 0603, Resistors for LEDs (optional)
  • 2x Wurth Elektronik Standoffs 9774015151 (optional)

The original version is generally fully functional, and I only made minor adjustments to the mounting holes for the CM4 stands and the tracks on the board. The new board looks like this (I’ll add pics after soldering):

The project is available on GitHub:

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Craig Engbrecht
Craig Engbrecht
1 month ago

First!
Jk, awesome collection of the information!
What was your main usecase for the mini board?
Knowing it has USB and gpio, what was the focus?
Wireless controller, remote access, wireless access for management?

Greg
Greg
1 month ago

Hi Ivan,

I really like the work you are doing!
One quick (noob) question though; Since I could use the UART Pins for 5V power supply – when retraced, can the USB-C port be re-used for data, i.e. USB-OTG then? The small form factor is really appealing, and makes me wanna go off-grid with this.

All the best!

Greg

Greg
Greg
Reply to  Greg
1 month ago

*Update*
Just learned that the high speed port side of the CM4 is left unused in this minimal design – never mind then.