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.