The Tombotron is an accompaniment instrument that I constructed and wired. It utilizes an Arduino Mega and midi input to allow a user, linked with another user on a keyboard midi controller, to play anything in the key of the other user. For example if you play an "A" chord on a normal midi controller, the output of that goes to the Tombotron and reprograms each of the buttons to only play notes and octaves related to that "A" chord. Essentially you have an instrument that continuously remaps itself to the input it receives from the midi controller, you can't play a wrong note! The housing is custom built and there are internal lights used for a light show effect. A keypad allows for multiple programs to be selected for light changes.One program featured in the video link below, changes the tempo of the light changes based on the tempo of the buttons pressed. Each of the 12 buttons has an RGB led assigned to it, so that when the incoming midi signal is received the light colors change to show which buttons are matching each octave. This was a year-long project where I learned a lot of new skills and problem solving.
video demonstration