BIGTREETECH Pi4B Adapter V1.0 for Raspberry-Pi CM4, BTT CB1 V2.2/CB1 eMMC/CB2 Core Board Compatible SKR Mini E3 V3.0/SKR V1.4 Turbo/Octopus V1.1/Pro to Running Klipper for Voron/CoreXY/i3 3D Printer

I have 2 of these now since it is almost impossible to find an actual pi. I had real trouble with the first one I bought in getting it to work correctly. BTT support was slow to answer but they did finally make it right buy replacing the CB1, After that it has worked great so I bought another and it worked the perfectly the first time I tried it. I believe that they have worked out the bugs and now they are a good product. I will probably be buying another.

Purchased to Load and test a CM4-Lite, Worked with no issues and arrived quickly... Not much more to say about it... has an SD card slot on bottom that does the job. tested with 4k30fps video got a bit choppy... but thats more of a pi4 thing..

This board is great in that it is almost identical to a Pi 4 model B in its layout—the ports are all in the exact same places, though the DSI and CSI display/camera connectors are slightly different due to the Compute Module's positioning. Also missing is any USB 3.0 (that is replaced by two extra USB 2.0 ports), and there is no PoE HAT compatibility. The Ethernet port is labeled as 1Gbps, but will only be 10/100 if you buy BigTreeTech's CB1 board instead of a CM4.There are a few dipswitches for setting write protect, flashing eMMC, etc., but they are very tiny and hard to reach, you need a tiny tool to get in there if you want to use this board to flash a device.There's also a 5V/GND header to plug in a non-PWM fan at the edge of the board.Overall it's put together well and works great with both a CB1 and CM4 that I've tested.