Nick Demopoulos built an amazing guitar-synth MIDI controller,  Smomid.

Smomid (String Modeling Midi Device) is a synth instrument in the shape of a guitar.  It’s incredibly versatile with a long list of features and functionality.  Thanks to some guidance offered on the forum, Nick was able to upgrade the micro controllers in the second version to a pair of Teensy 3.6s.

You can find recordings of Nick playing Smomid on his website.