#define trigPin 9
#define echoPin 10

void setup () {
  Serial.begin(9600);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
}

void loop() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  long duration = pulseIn(echoPin, HIGH);
  int jarak = duration * 0.03421/2;

  Serial.print("jarak : ");
  Serial.println(jarak);
  delay(1000);
}