The sketch rusn a first Arduino to read a midi signal and coverts it to a voltage at one of 12 levels that is communicated to the guitar controller Arduino. Why voltages and not serial data? Becuase I messed the clock up on the controller Arduio to run it a bit faster and the serial communication routines do not function.
This sketch runs a second Arduino which reads the signal from the midi module and controls string tension for two strings. It also does real time tuning correction which is why it is somewhat complicated. It is a work in progress, so please forgive the mess.