#define echoPin 2
#define trigPin 3

int maximumRange = 300;
int minimumRange = 00;
long duration, distance;

void setup() {
  Serial.begin (9600);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(9, OUTPUT);
  pinMode(10, OUTPUT);
  pinMode(11, OUTPUT);
}

void loop() {
  /* Penentuan Jarak. */
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);

  //perhitungan untuk dijadikan jarak
  distance = duration/58.2;

  /* jika jarak melebihi 300 cm,
    kirim keterangan "Di Luar jangkauan" */

    if (distance >= maximumRange || distance <= minimumRange) {
      Serial.println("Di Luar jangkauan");
    }
    else {

      /*
      kirim hasil pembacaan jarak melalui serial monitor
      */
      Serial.print("Jarak : ");
      Serial.print(distance);
      Serial.println(" cm");

      delay(100);
    }

    if (distance <= 100){
      digitalWrite(11, HIGH);
      digitalWrite(10, LOW);
      digitalWrite(9, LOW);
    }
    if(distance >= 100 && distance <= 200) {
      digitalWrite(11, LOW);
      digitalWrite(10, HIGH);
      digitalWrite(9, LOW);
    }
    if(distance >= 200) {
      digitalWrite(11, LOW);
      digitalWrite(10, LOW);
      digitalWrite(9, HIGH);
}
}