Latching Footswitch to MIDI Converter

Projects Programming
7

If you auto-formatted your code you can see that in loop() you had all of the processing within the if (buttonState == 1) conditional. buttonState is 1 (HIGH) when the switch is open and so you immediately turned on the LED. When buttonState was 0 (LOW) you never turned the LED off because everything was within the if (buttonState == 1) conditional.

void loop() {
  buttonState = digitalRead(buttonPin);

  // status?
  if (buttonState == 1) {
    // switch closed
    if (muteStatus == 0) {
      // mute and light up LED
      digitalWrite(ledPin, HIGH);
      // send CC 85 on channel 2 with value 0 to mute
      // mute group 6 on a Behringer X32
      midiCc(2, 85, 0);
      muteStatus = 1;
    }

    buttonState = digitalRead(buttonPin);

    if (buttonState == 0) {
      // switch open
      if (muteStatus == 1) {
        // unmute and dim  LED
        digitalWrite(ledPin, LOW);
        // send CC 85 on channel 2 with value 127 to mute
        // unmute group 6 on a Behringer X32
        midiCc(2, 85, 127);
        muteStatus = 0;
      }
    }
    // workaround to prevent fluttering of button state
    delay(10);
  }
}