Media Keys

const int Row[2] = { 2, 1 };          // initialize the row and column pins

const int Col[3] = { 3, 4, 0 };

int c1 = 1; // set up vars for the column states
int c2 = 1;
int c3 = 1;

void setup() {
  // set modes of rows and columns
  pinMode(Row[0], OUTPUT);
  pinMode(Row[1], OUTPUT);

  pinMode(Col[0], INPUT);
  pinMode(Col[1], INPUT);
  pinMode(Col[2], INPUT);

  digitalWrite(Col[0], HIGH); //enable the internal pull up resistors
  digitalWrite(Col[1], HIGH);
  digitalWrite(Col[2], HIGH);

}

void loop() {
  digitalWrite(Row[0], LOW); //pull low the row we are querying
  digitalWrite(Row[1], HIGH);

  c1 = digitalRead(Col[0]); //grab button states
  c2 = digitalRead(Col[1]);
  c3 = digitalRead(Col[2]);

  if (c1 == LOW) {
    Remote.decrease();
    Remote.clear(); //reset the key state to prevent repeating keys
    c1 = 1;
    delay(200); //debounce
  }

  else if (c2 == LOW) {
    Remote.mute();
    Remote.clear();
    c2 = 1;
    delay(200);
  }

  else if (c3 == LOW) {
    Remote.increase();
    Remote.clear();
    c3 = 1;
    delay(200);
  }

  digitalWrite(Row[0], HIGH); //select the other row
  digitalWrite(Row[1], LOW);

  c1 = digitalRead(Col[0]);
  c2 = digitalRead(Col[1]);
  c3 = digitalRead(Col[2]);

  if (c1 == LOW) {
    Remote.previous();
    Remote.clear();
    c1 = 1;
    delay(200);
  }

  else if (c2 == LOW) {
    Remote.TogglePlay();
    Remote.clear();
    c2 = 1;
    delay(200);
  }

  else if (c3 == LOW) {
    Remote.next();
    Remote.clear();
    c3 = 1;
    delay(200);
  }
}