long bacaJarak (int triggerPin, int echoPin){
  pinMode(triggerPin, OUTPUT);
  digitalWrite(triggerPin, LOW);
  digitalWrite(triggerPin, HIGH);
  delayMicroseconds(19);
  digitalWrite(triggerPin, LOW);
  pinMode(echoPin, INPUT);
  return pulseIn(echoPin, HIGH);
}

void setup() {
  Serial.begin(9600);
}

void loop() {
  // pembacaan ultrasonik
  int cm = 0;
  cm = (0.03446 * bacaJarak(7, 8))/2;
  int mm = cm*100;
  // menampilkan pembacaaan sensor di monitor
  Serial.println("Jarak: ");
  Serial.print(cm);
  Serial.println("cm");
  delay(100);
}