#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2); // Alamat I2C LCD

const int pHPin = A0;        // Sensor pH di A0
const int turbidityPin = A1; // Sensor kekeruhan di A1
const int buzzerPin = 8;     // Buzzer di D8
const int greenLED = 9;      // LED Hijau di D9
const int redLED = 10;       // LED Merah di D10

float pHValue, turbidityValue;

void setup() {
  Serial.begin(9600);
  lcd.init();
  lcd.backlight();
  pinMode(buzzerPin, OUTPUT);
  pinMode(greenLED, OUTPUT);
  pinMode(redLED, OUTPUT);
  
  lcd.setCursor(0, 0);
  lcd.print("Kualitas Air");
  delay(2000);
}

void loop() {
  // Baca nilai pH
  pHValue = analogRead(pHPin) * (5.0 / 1023.0); // Konversi ke voltase
  pHValue = 3.5 * pHValue; // Kalibrasi sesuai kebutuhan
  
  // Baca nilai kekeruhan (NTU)
  turbidityValue = analogRead(turbidityPin);
  turbidityValue = map(turbidityValue, 0, 1023, 0, 100); // Konversi ke persen
  
  // Tampilkan di LCD
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("pH: ");
  lcd.print(pHValue, 2);
  
  lcd.setCursor(0, 1);
  lcd.print("Kekeruhan: ");
  lcd.print(turbidityValue);
  lcd.print("%");
  
  // Evaluasi kualitas air
  if (pHValue >= 6.5 && pHValue <= 8.5 && turbidityValue < 50) {
    digitalWrite(greenLED, HIGH); // Air baik
    digitalWrite(redLED, LOW);
    noTone(buzzerPin);
  } else {
    digitalWrite(greenLED, LOW);
    digitalWrite(redLED, HIGH); // Air buruk
    tone(buzzerPin, 1000); // Bunyikan alarm
    delay(500);
    noTone(buzzerPin);
  }
  
  delay(2000); // Update setiap 2 detik
}