Arturo182 Beats Raspberry Pi to the Punch, Converts the Raspberry Pi 5 Into the "Unofficial CM5"
Clever interstitial board and some adapters, plus plenty of FFCs, provide a CM4-compatible Raspberry Pi Compute Module 5 — of sorts.
Pseudonymous maker "Arturo182," of Solder Party fame, has beaten Raspberry Pi to the punch with the first Compute Module 4-compatible Raspberry Pi 5 adaptation — functional, but not exactly as compact as a true Raspberry Pi Compute Module 5.
"The Raspberry Pi 5 has been available for 2 weeks now, and still no CM5 [Compute Module 5]? Sorry, this will not stand," Arturo182 writes of the project. "Time for me to take matters into my own hands! Introducing, the (not really) CM5! The power of RPi 5 in the CM4 form-factor."
The Raspberry Pi 5 launched late last month as the most powerful single-board computer the company has yet designed. At present, it's also the only one to use the new Broadcom BCM2712 system-on-ship and the in-house Raspberry Pi RP1 southbridge chip: no announcement of a similarly-equipped Raspberry Pi Compute Module 5 system-on-module (SOM) is expected until some time next year, leaving those with CM4 carrier boards eager for more computing power bereft.
That's where Arturo182's "Unofficial RPi CM5" board comes in. Designed as an interstitial board, the adapter sits between a device which expects a Raspberry Pi Compute Module 4 or compatible SOM and the full-size Raspberry Pi 5 single-board computer — adapting signals from one to the other, and providing that extra computational oomph ahead of a true Compute Module 5 launch.
"How? Lots and lots of flex cables and adapters," Arturo182 writes. "PCIe [PCI Express], DSI [Display Serial Interface], and CSI [Camera Serial Interface] connect directly to the RPi 5, for HDMI, microSD, USB C, and USB A, there are adapters. [I've tested it] running off of an M.2 NVME drive over PCIe. microSD is also an option. (2×) HDMI, USB, DSI, and CSI are all there, of course. As well as all the GPIOs [General Purpose Input/Output pins]."
While the adapter exists and is functional, the silkscreen layer reveals the design as "just a meme [and] not serious." More information is available in Arturo182's Mastodon thread.