void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  DDRD = DDRD | B11110100; //Sets Digital Pins 2, 4, 5, 6, 7 as Outputs - Buzzer = Pin 2, Green LED's = Pins 4, 5, 6, 7
  DDRB = DDRB | B00001111; //Sets Digital Pins 8, 9, 10, 11 as Outputs - Red LED's = Pins 8, 9, 10, 11
  //************************************************************************************************************************
  //STARTUP ROUTINE - All LED's FLASH TWICE
  PORTD |= B11110000; //Turns on all Green LED's
  PORTB |= B00001111; //Turns on all Red LED's
  delay(500);
  PORTD &= ~(B11110000); //Turns off all Green LED's
  PORTB &= ~(B00001111); //Turns off all Red LED's
  delay(500);
  PORTD |= B11110000; //Turns on all Green LED's
  PORTB |= B00001111; //Turns on all Red LED's
  delay(500);
  PORTD &= ~(B11110000); //Turns off all Green LED's
  PORTB &= ~(B00001111); //Turns off all Red LED's
  delay(2000);
  //************************************************************************************************************************
}

void loop() {
  // put your main code here, to run repeatedly:
  if (PINB & (1 << 4)) { //If Pin 12 is HIGH (Triggered) - RCWL-0516 Attached to Digitial Pin 12.
    buzzer();
    PORTD |= B11110000; //Turns all The Green LED's ON
    delay(500);
    PORTD &= ~(B11110000); //Turns all The Green LED's OFF
    delay(500);
    PORTB |= B00001111; //Turns all The Red LED's ON
    delay(500);
    PORTB &= ~(B00001111); //Turns all The Red LED's OFF
    delay(500);
  }
  else {
    Serial.println("Waiting for Trigger");
  }
}

void buzzer() {
  tone(2, 500, 2000);
}