// Pin untuk Ultrasonic Sensor
const int trigPin = 25;
const int echoPin = 33;

// Pin untuk Relay
const int relayPin = 26;

// Pin untuk LED
const int led1 = 13;
const int led2 = 12;
const int led3 = 14;
const int led4 = 27;

// Variabel untuk pengukuran
long duration;
int distance;
int maxDistance = 100;  // Tinggi tangki air dalam cm (sesuaikan)

// Setup pin
void setup() {
  // Setup pin ultrasonic
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  
  // Setup pin relay dan LED
  pinMode(relayPin, OUTPUT);
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
  pinMode(led4, OUTPUT);
  
  // Mulai komunikasi serial untuk debugging
  Serial.begin(115200);
}

void loop() {
  // Mengirim sinyal ultrasonik
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Mengukur waktu pantulan kembali
  duration = pulseIn(echoPin, HIGH);
  
  // Menghitung jarak dalam cm
  distance = duration * 0.034 / 2;

  // Menghitung ketinggian air (jika sensor ditempatkan di atas tangki)
  int ketinggianAir = maxDistance - distance;

  // Debugging untuk menampilkan nilai
  Serial.print("Jarak: ");
  Serial.print(distance);
  Serial.println(" cm");
  
  Serial.print("Ketinggian Air: ");
  Serial.print(ketinggianAir);
  Serial.println(" cm");

  // Kontrol relay dan LED berdasarkan ketinggian air
  if (ketinggianAir < 10) {
    // h < 10% - Relay ON, LED 1 ON, LED lainnya OFF
    digitalWrite(relayPin, HIGH);
    digitalWrite(led1, HIGH);   // LED 1 ON
    digitalWrite(led2, LOW);    // LED 2 OFF
    digitalWrite(led3, LOW);    // LED 3 OFF
    digitalWrite(led4, LOW);    // LED 4 OFF
  }
  else if (ketinggianAir < 40) {
    // h < 40% - Relay ON, LED 1 ON, LED 2 OFF, LED 3 OFF
    digitalWrite(relayPin, LOW);
    digitalWrite(led1, HIGH);   // LED 1 ON
    digitalWrite(led2, LOW);    // LED 2 OFF
    digitalWrite(led3, LOW);    // LED 3 OFF
    digitalWrite(led4, LOW);    // LED 4 OFF
  }
  else if (ketinggianAir < 70) {
    // h < 70% - Relay OFF, LED 1 dan 2 ON, LED 3 OFF
    digitalWrite(relayPin, LOW);
    digitalWrite(led1, HIGH);   // LED 1 ON
    digitalWrite(led2, HIGH);   // LED 2 ON
    digitalWrite(led3, LOW);    // LED 3 OFF
    digitalWrite(led4, LOW);    // LED 4 OFF
  }
  else if (ketinggianAir < 100) {
    // h < 100% - Relay OFF, LED 1, 2 dan 3 ON
    digitalWrite(relayPin, LOW);
    digitalWrite(led1, HIGH);   // LED 1 ON
    digitalWrite(led2, HIGH);   // LED 2 ON
    digitalWrite(led3, HIGH);   // LED 3 ON
    digitalWrite(led4, LOW);    // LED 4 OFF
  }
  else {
    // h = 100% - Relay OFF, Semua LED ON
    digitalWrite(relayPin, LOW);
    digitalWrite(led1, HIGH);   // LED 1 ON
    digitalWrite(led2, HIGH);   // LED 2 ON
    digitalWrite(led3, HIGH);   // LED 3 ON
    digitalWrite(led4, HIGH);   // LED 4 ON
  }

  delay(1000);  // Tunggu 1 detik sebelum pembacaan ulang
}