int ampOff = 4;//AMP Shutdown
int PirAlarm = 3;//Speaker buzzer pin

//pir
int Pirsensor = 8;//the pin that the sensor is attached to
int PirState = LOW;//default to show no motion detected
int sensorvalue;//to store sensor status

void setup()
{
  pinMode(ampOff, OUTPUT);
  digitalWrite(ampOff, LOW);
  pinMode(Pirsensor, INPUT);
  Serial.begin(9600);
}  

void loop()
{
  //pir
  sensorvalue = digitalRead(Pirsensor);//read value on sensor
  if (sensorvalue == HIGH)// check if the sensor is HIGH
  {
    digitalWrite(PirAlarm, HIGH);   //turn speaker ON
    Serial.println("Motion detected!");
    delay(500);                // delay 500 milliseconds
  }
  else
   {
    digitalWrite(PirAlarm, LOW); //turn speaker OFF
    delay(500);// delay 500 milliseconds
    digitalWrite (ampOff, HIGH);
    Serial.println("Car is empty!");
   
    }
}