int pir=0;
int sensor_pir=4;
int buzzer=5; 
void setup() {
  pinMode( sensor_pir, INPUT);
  pinMode(buzzer, OUTPUT);
  Serial.begin(9600);
  // put your setup code here, to run once:

}

void loop() {
 pir=digitalRead(sensor_pir);
  if(pir==HIGH){
    Serial.println("ada tamu");
    tone(buzzer, 250);
  }
  else{
    Serial.println("tidak ada tamu");
    tone(buzzer, LOW);
  }
  delay(1000);
  // put your main code here, to run repeatedly:

}