int ledPin = 13;                
int pir = 2;               
int pirState = LOW; 
int trig = 3;
int echo = 4;                              
int buzz = 11;

void setup() {
  pinMode(ledPin, OUTPUT);      
  pinMode(pir, INPUT);  
  pinMode(trig, OUTPUT);
  pinMode(echo, INPUT);   
  pinMode(buzz, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  digitalWrite(trig, LOW);
  delayMicroseconds(5);
  digitalWrite(trig, HIGH);
  delayMicroseconds(15);
  digitalWrite(trig, LOW);

  long durasi = pulseIn(echo, HIGH);
  
  long jarak = (durasi * 0.034) / 2;
  
  if (jarak > 0 && jarak < 50) {
    tone(buzz, 1000); 
    digitalWrite(ledPin, LOW);
    
  } 
  else {
    noTone(buzz);  
    digitalWrite(ledPin, HIGH);
  }
   if (jarak > 51 && jarak < 100) {
    tone(buzz, 100); 
    digitalWrite(ledPin, LOW);
    
  } 
  else {
    noTone(buzz);  
    digitalWrite(ledPin, HIGH);
  }
}