Findecanor wrote: Hasn't someone not written a keyboard controller driver for the Raspberry Pi's GPIO pins / Raspbian already?
Yes, I looked into that when I was planning this, but if I did that, I wouldn't be able to add a switch to change between sources, and have this just function as a regular keyboard when I don't need or want the Rpi.
Plus that would probably take me a week just to make and debug, and I was anxious to get this up and running.
On that same idea, I have been thinking that if I used a Raspberry Pi A+ I could use the GPIO header and essentially build a keyboard on-top of the Rpi, and make a very very compact version of this by just making a PCB with the matrix, and directly mount that PCB onto the GPIO header. Then solder the switches in.
Think of a dedicated Emacs box.
-Ezra