#define trigPin 9
#define echoPin 10
#define buzzerPin 13

void setup() {
 Serial.begin(9600);
 pinMode(trigPin, OUTPUT);
 pinMode(echoPin, INPUT);
 pinMode(buzzerPin, OUTPUT);
}
void loop() {
 long duration, distance;
 digitalWrite(trigPin, LOW);
 delayMicroseconds(2);
 digitalWrite(trigPin, HIGH);
 delayMicroseconds(10);
 digitalWrite(trigPin, LOW);
 duration = pulseIn(echoPin, HIGH);
 distance = (duration * 0.034) / 2;


 Serial.print("Jarak: ");
 Serial.print(distance);
 Serial.println(" cm");
delay(100);

  if      (distance>200 && distance<250) 
    {tone (buzzerPin, 1000, 200); 
    delay(400);}
  else if (distance>100 && distance<201) 
    {tone (buzzerPin, 1000, 200); 
    delay(200);}
  else if (distance<101)                 
    {tone (buzzerPin, 1000, 200); 
    delay(100);}
  else    
  {noTone(buzzerPin);}
}