Latching Footswitch to MIDI Converter

Projects Programming
5

I would recommend using state change detection. It eliminates having to use extra flags:

// pin to use for indicator LED
const int ledPin = 12;
// pin that is connected to the footswitch
const int buttonPin = 2;

int buttonState = 0;
int buttonLastState = digitalRead(buttonPin);;

void setup() 
{
  pinMode(ledPin, OUTPUT);
  pinMode(buttonPin, INPUT_PULLUP);

  // Setup serial port for MIDI communication
  Serial.begin(31250);

}

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

  if (buttonState != buttonLastState)
  {
    delay(50); // debounce
    buttonLastState = buttonState;
    if (buttonState == LOW) // went from HIGH to LOW (closed)
    {
      // 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);
    }
    else  // went from LOW to HIGH (opened)
    {
      // 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);
    }
  }
}

void midiCc(int channel, int command, int value) {
  Serial.write(175 + channel);
  Serial.write(command);
  Serial.write(value);
}