#define pinPir 2
#define relay 3

void setup() {
  pinMode(pinPir, INPUT_PULLUP);
  pinMode(relay, OUTPUT);
}

void loop() {
  int nilaiPir = digitalRead(pinPir);
  if(nilaiPir == 0){
    digitalWrite(relay, HIGH);
  }
  else{
    digitalWrite(relay, LOW);
  }
}