André Costa's CM4 Ether Board Is a Compact, Rackmountable Raspberry Pi Compute Module 4 Carrier
Offering Ethernet, USB, and M.2 NVMe connectivity, this small-footprint carrier packs only the essentials for network operation.
Maker André Costa has designed a small form factor carrier board for the Raspberry Pi Compute Module 4 and compatible systems-on-modules (SOMs), for projects where you need Ethernet connectivity and not much else: the CM4 Ether Board.
"The CM4 Ether Board is a compact, no-frills carrier board for the Raspberry Pi CM4 and other compatible compute modules," Costa explains of the board design. "It has a streamlined form factor that fits vertically in a 1U server rack or can be tucked away inside an enclosure. It provides a compact platform for tinkerers creating a cluster or setting up their home lab."
The main feature of the CM4 Ether Board is, of course, its Ethernet port, connecting to the Raspberry Pi Compute Module 4 or compatible to the network. Next to this is a USB Type-C port, used for power, with a micro-USB On-The-Go (OTG) connector for peripherals — with a secondary device mode allowing the port to be used to flash an operating system onto the CM4's eMMC storage.
Given the minimalist nature of the carrier board, that's almost it — except for a very handy feature hidden on the back: an M.2 slot, connected to the CM4's PCI Express lane and providing room for high-performance Non-Voltatile Memory Express (NVMe) storage. Speaking of storage, though, Costa notes that only the full-fat CM4 with eMMC is supported, as the carrier lacks the microSD slot required for a CM4 Lite. "This might change in the future," the maker says.
Other features of the board include solder jumpers for disabling the CM4's Wi-Fi and Bluetooth radios and compatibility with a 3D-printable rack-mount enclosure designed to hold four carrier boards side-by-side. "This is the mini server that I have running in my basement," Costa says of that particular configuration. "I do all of the development for rpilocator.com on one."
More details on the carrier board are available on the DPHacks website, while assembled units can be purchased from Tindie at $22.
