int led=4;
int ir=11;
int sensor;
void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
pinMode(led,OUTPUT);
pinMode(ir,INPUT);

}

void loop() {
 sensor=digitalRead(ir);
 if(sensor==HIGH){
  digitalWrite(led,HIGH);
  Serial.println("Motion Detect");
  delay(500);
  } 
  else{
    digitalWrite(led,LOW);
    Serial.println("Motion Stoped");
    delay(500);
  }
}