int led=13;
int sensor=2;
int state=LOW;
int val=0;
void setup()
{
  pinMode(led,OUTPUT);
  pinMode(sensor, INPUT);
  Serial.begin(9600);
}
void loop()
{
  val=digitalRead(sensor);
  if(val==HIGH)
  {
    digitalWrite(led,HIGH);
    delay(100);
    if(state==LOW)
    {
      Serial.println("Motion detected!");
      state=HIGH;
    }
  }
  else{
    digitalWrite(led,LOW);
    delay(200);
    Serial.println("motion stopped!");
  }
}