int val = 0;             
int PIR = 2;              

const int relaypin = 3 ;
void setup() {
  pinMode(relaypin, OUTPUT);   
  pinMode(PIR, INPUT);    
  Serial.begin(9600);     
}

void loop(){
  if (digitalRead(PIR) == HIGH) { 
    digitalWrite(relaypin, HIGH);       
    Serial.println("Motion detected!"); 
    delay(100);                    
  } 
  else {
    digitalWrite(relaypin, LOW);       
    Serial.println("Motion stopped!");
    delay(100);                   
  }
}