//Define pin variables
int Alarm_Set = A0;
int Alarm_Tone = 9;

void setup()
{
  //Setup input and output pins
  pinMode(Alarm_Set, INPUT);
  pinMode(Alarm_Tone, OUTPUT);
}

void loop()
{
  //Check if alarm_tone should output 440Hz or 0Hz
  if (digitalRead(A0) == HIGH)
  {
    tone(Alarm_Tone, 440, 100);
  }
  else
  {
    tone(Alarm_Tone, 0, 100);
  }
}