I've got some extra micro controllers and buttons I wanted to add to my saber to allow me some other user inputs to do things like configure the blade color or potentially some other function I dream up, but I couldn't see any way to provide extra inputs or functions to the CFX board, aside from potentially hijacking the serial data lines (which would be a serious undertaking, at best). I have an Adafruit lightsaber circuit setup, and while it's a fun little demo, it's very limited from a swing-sound perspective, without getting into writing some new sound drivers and more or less reinventing the wheel.

Is there any way to add new functions like this to a CFX? What about other boards on the market? Proffie boards?