Audio Output

#define NOTE_C4  262 //From pitches.h file defined in [Arduino Tone Tutorial][1]

int Key = 2;
int KeyVal = 0;

byte speaker = 12;

void setup()
{
  pinMode(Key, INPUT);  //Declare our key (button) as input
  pinMode(speaker, OUTPUT);
}

void loop()
{
  KeyVal = digitalRead(Key);
  if (KeyVal == HIGH) {
    tone(speaker, NOTE_C4); //Sends middle C tone out through analog speaker
  } else {
    noTone(speaker); //Ceases tone emitting from analog speaker
  }

  delay(100);
}