In between preparing for our move (we're actually starting the move today!) I've been poking at this project some more. I've made some updates to the documentation to make it easier to follow, and even added some useful links to the README! I think I've also narrowed down what parts I want to use for this: the Arduino Micro or SparkFun Pro Micro for the master microcontroller, and the Arduino Pro Mini for the key matrix scanning controllers.

One other big update is that I think I've settled on using SPI to connect the matrix scanning controllers to the master. I was initially planning on using I2C for this, but SPI gives me the ability to upgrade the firmware for the slave controllers directly from the master. This should make it much easier to update the board, without having to have 2 or 3 separate programming headers.

I also revisited the key matrix designs, since the ones I had previously were all based on having one big matrix for the whole keyboard. The new design will have 2 separate matrices, one for each side.