Hello, I have made great progress in the meantime, thank you very much for this great project.

I'm currently calibrating, sensor 1, up to group eleven my LEDs on the Teensy are off and I get the buttons calibrated, at group 11-14-17 it is permanently on and I can turn the potentiometer as I want nothing changes, so I thought of a faulty board. I connected board 4 to the sensors of board 11 and redirected it. No change, board 4 is on even though it was off before. it must have another reason., Is it because I only use 17 boards but the code is on 18? I have an 85-key piano. Do you have an idea? Alternatively, I have to test the IDE, I hope that there has not been an error. Best regards from Germany Tim.