Raspberry Pi Compute Module 4

The Raspberry Pi Compute has become a tradition that we follow each Raspberry Pi model with a system-on-module variant based on the same core silicon. Raspberry Pi 1 gave rise to the original Compute Module in 2014; Raspberry Pi 3 and 3+ were followed by Compute Module 3 and 3+ in 2017 and 2019 respectively. Only Raspberry Pi 2, our shortest-lived flagship product at just thirteen months, escaped the Compute Module treatment.

Six months after the release of the Raspberry Pi 4 we finally saw the New Compute 4 Module. For users who want a more compact or custom form factor, or on-board eMMC storage, Compute Module products provide a simple way to move from a Raspberry Pi-based prototype to volume production.

You can find the details specs here, but let’s run through the highlights:

  • 1.5GHz quad-core 64-bit ARM Cortex-A72 CPU
  • VideoCore VI graphics, supporting OpenGL ES 3.x
  • 4Kp60 hardware decode of H.265 (HEVC) video
  • 1080p60 hardware decode, and 1080p30 hardware encode of H.264 (AVC) video
  • Dual HDMI interfaces, at resolutions up to 4K
  • Single-lane PCI Express 2.0 interface
  • Dual MIPI DSI display, and dual MIPI CSI-2 camera interfaces
  • 1GB, 2GB, 4GB or 8GB LPDDR4-3200 SDRAM
  • Optional 8GB, 16GB or 32GB eMMC Flash storage
  • Optional 2.4GHz and 5GHz IEEE 802.11b/g/n/ac wireless LAN and Bluetooth 5.0
  • Gigabit Ethernet PHY with IEEE 1588 support
  • 28 GPIO pins, with up to 6 × UART, 6 × I2C and 5 × SPI

32 variants

With four RAM options, four Flash options, and optional wireless connectivity, we have a total of 32 variants, ranging from the 1GB RAM, Lite, no wireless variant to the 8GB RAM, 32GB Flash, wireless variant.

With a range of IO boards already released, we will have a quick look at the Waveshare Raspberry Pi Compute Module 4 IO Board With PoE

Waveshare Raspberry Pi Compute Module 4 IO Board With PoE

IO Board Specs

To clarify let’s take look at a quick rundown of the specs before we start:

  • integrates 802.3af-compliant PoE circuit (5V/2.5A)
  • 4x USB 3.2 Gen1 ports Micro USB port
  • Gigabit Ethernet RJ45 with PoE support
  • 40PIN GPIO header
  • 5V / 12V standard fan connector
  • CM4 SOCKET suitable for all variants of Compute Module 4
  • Real-time clock with battery socket and ability to wake Compute Module 4
  • 2x MIPI DSI display FPC connectors (22-pin 0.5 mm pitch cable)
  • 2x MIPI CSI-2 camera FPC connectors (22-pin 0.5 mm pitch cable)
  • MicroSD card socket for Compute Module 4 Lite (without eMMC) variants
  • DIMENSIONS 160 × 90mm

First time setup

What do you need:

Lets Get Started in less than 10 easy steps!

  1. Connect the CM4 to PC by Micro USB cable
  2. Download the rpiboot tools and install it as administrator
  3.  Download Raspberry Pi Imager 
  4. Follow instructions provided below to mount the CM4 as USB drive
  5. Connect 12V power adapter to IO Board.
  6. Once the CM4 is mounted as a bootable USB drive install Raspberry Pi OS as you would a SD card using the Raspberry Pi imaging tool .
  7. Most importantly remove the 7V~36V power cable before removing the USB cable and jumper inserted as above.
  8. Plug in your HDMI connected to a display, possibly a USB keyboard and mouse.
  9. Re-insert power to start up your CM4 and you will be greeted with the same Rpi desktop we all know and love.

That’s it.

Writing the Image

If your Compute Module 4 (CM4 hereafter) is the LITE version, you just need to write the image to Micro SD card like Raspberry Pi boards. However if you are using the eMMC version, you need to connect the CM4 to PC by Micro USB cable. Download the rpiboot tools and install it as administrator. Download newest Raspberry Pi OS image from Raspberry Pi Website.

If you use the eMMC version, you need to connect the CM4 to the IO board. Connect the BOOT pin of IO board to the GND . Then the USB SLAVE Interface of IO board is connected to your PC. Connecting the 12V power adapter to the IO Board. A device named BCMxxx should now be recognized, and you need to run the rpiboot software, to recognized eMMC of CM4 as a portable drive.

Format SD card

You need to format the MicroSD card or the eMMC using the Raspberry Pi imaging tool software. Write image: You need to write the image to Micro SD card or the eMMC using the Raspberry Pi imaging tool software.


Insert the Micro SD card into the card slot and connect the 12V power adapter. Power indicator turn solid red and the ACT is green and blink while booting.

If you use the eMMC version, don’t forget to disconnect the nRPI_BOOT J2 jumpers when powering off and reboot.

If you failed to write the eMMC, please try with the following steps:

  • User Windows PC instead of Windows 7 or Linux. It seems that Windows 7 or Linux PC is not stable for eMMC writing.
  • Check your CM4, make sure that it is the eMMC version which has one more eMMC chip compare to the LITE version..
  • Note that you need to connect 12 power adapter to the Power port.
  • Please change a USB cable for a try and make sure that the cable is data accessible.
  • Change the USB port of the PC and try it again.
  • Try to restart your PC.
  • Re-connect the CM4 for a try.
  • Try with other PCs.