int pirState = LOW; 
int val = 0; 
void setup() {
  // put your setup code here, to run once:
  pinMode(13, OUTPUT);
  pinMode(2, INPUT);
  Serial.begin(9600);
}

void loop() {
   val = digitalRead(2); 
  if (val == HIGH) {            
    digitalWrite(13, HIGH); 
    if (pirState == LOW) {
      Serial.println("Motion detected!");
      pirState = HIGH;
    }
  } else {
    digitalWrite(13, LOW);
    if (pirState == HIGH){
      Serial.println("Motion ended!");
      pirState = LOW;
    }
  }
  delay(2000);
}