int buzzerPin = 10;     //Outputs 5v to switch a relay or sound a DC powered buzzer. Change to desired pin.
int extLED = 9;         //Outputs 5v for an external LED that turns on with the buzzer. Will require resistor. Change to desired pin.
int toneGenOut = 8;     //Outputs a frequency to drive piezos or any buzzer that requires a frequency. Change to desired pin.

void setup() {
  pinMode(buzzerPin, OUTPUT);     //Designates pins as outputs.
  pinMode(extLED, OUTPUT);        //
  pinMode(toneGenOut, OUTPUT);    //
  pinMode(LED_BUILTIN, OUTPUT);   //
}

void loop() {

  delay(20000);   //Waits 20sec. Can adust to prefered value. (20000 = 20 seconds)

  while(true) {

    digitalWrite(buzzerPin, HIGH);    //Brings outputs high after set time. Stays on forever until power is disconnected.
    digitalWrite(extLED, HIGH);       //
    digitalWrite(LED_BUILTIN, HIGH);  //
    tone(toneGenOut, 800);            //Change this number to change the tone frequency. (800 = 800 hz)

  }
}