[HELP] Midi button LED control code.

Other Hardware LEDs and Multiplexing
11

OK - just re reading your first post:-

and a Teensy 3.2.

And in the code you say:-

#include "MIDIUSB.h"

Do you know that the MIDIUSB libiary is not compatible with the Teensy?
If you want to use a Teensy then you have to use the USB_MIDI libiary :- Teensyduino: Using USB MIDI with Teensy on the Arduino IDE