What is SpaceFN and why you should give it a try
The SpaceFN concept - setting up your space key as a layer switch when held - is probably one of the most useful tweaks in the keyboard hobby. Let me explain how it works. My SpaceFN article on kbd.news made some rounds recently - quite surprisingly given the age of this concept. This piece you're reading is a condensed version of the full post. If you're left with unanswered questions, you'll most likely find the info you're looking for in the original write-up. On my imaginary top list of the most useful keyboard features, tweaks and hacks, SpaceFN would deserve a podium finish for sure. But what makes it so special? In short: SpaceFN is easy to implement, easy to learn, costs nothing, can be used with any keyboard, and can improve your productivity instantly. I will list its benefits below, but can state right at this point that the SpaceFN concept, setting up your space key as a layer switch when held, is clearly one of the most useful tweaks in the keyboard hobby....
Apr 30, 2024
I haven't decided yet if I will do it or not, however, what I would probably do is run it on both pro micro and pi. I would use a toggle switch to physically switch between the female keyboard output, and to power the raspberry pi.
However, if I needed to run both the pi and the preserve the USB keyboard functionality simultaneously, I would STILL need a toggle switch, to disconnect the keyboard from the pi so the strokes don't get sent to both OS's at the same time, even if I had the ability to do so.
Just a bit of reality I came to knocking this idea around in my head as well.
The pi is garbage for doing USB as it non-native. If you want no pro-micro and ONLY a pi, you will need to directly wire the matrix, and do it yourself. I think that amount of work isn't worth it.