Waveshare Nano Base Board, Compatible with Raspberry Pi Compute Module 4

I looked everywhere, on the Amazon ad, on Waveshare's wiki, and could not find the THICKNESS dimension for this. So here it is: the thickness when stacked on a CM4, in total, is 15.1mm. That's right, it's not only half the footprint of a Pi 4B, but also thinner at the same time, INCLUDING the CM4. Also, Waveshare's wiki page is very useful, as I've come to expect from Waveshare. I am happy.

I'm just going to come out and say it- Waveshare makes some good stuff and provides above average support/documentation. It really is the same footprint as the CM4, as you can see in my attached pix.One Star off for:1. No mounting holes. Suppose I could have seen that from the pix, but if you mount the CM to something, the only thing holding this board on are the two CM connector sockets. Considering this base board will have cabled stuff attached to it, I can see that putting stress on the CM4 connections and likely causing them to disconnect. What a terrible omission IMHO. Probably need to fashion a clip to 3D print.2. While they have a pretty good wiki and guide, there is no mention of it in the listing nor included with the product itself. Fortunately, they are easy to find with a quick google.Otherwise, their 'Mini' series might be a better choice, since they have holes to securely attach the CM4, however the Mini base boards make a CM4 more like a regular RPi.

I have a number of different IO boards for the Pi CM4, and this one impressed me by not only being the most compact, size-wise, but also still managing to include a number of useful components. Soldering on the GPIO header was a breeze, and there remains plenty of space between the header and the CM4 board, so there's no worries about scratching the board. My only wish would be for a full-size HDMI port, but fortunately mini-HDMI cords aren't too hard to come by, given that they are also used for the Raspberry Pi Zero boards.