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

#define LDR_PIN A0

const float GAMMA = 0.7;
const float RL10 = 50;

// Inisialisasi LCD dengan alamat I2C (biasanya 0x27 atau 0x3F)
LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup() {
  pinMode(LDR_PIN, INPUT);
  pinMode(4, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(2, OUTPUT);
  Serial.begin(9600);

  // Inisialisasi LCD
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Initializing...");
  delay(2000);
}

void loop() {
  int analogValue = analogRead(LDR_PIN);
  float voltage = analogValue / 1024.0 * 5.0;
  float resistance = 2000.0 * voltage / (1.0 - voltage / 5.0);
  float lux = pow(RL10 * 1e3 * pow(10, GAMMA) / resistance, (1.0 / GAMMA));

  lcd.clear();
  lcd.setCursor(0, 0);

  if (lux >= 0 && lux < 20) {
    lcd.print("Cahaya Gelap");
    digitalWrite(4, HIGH);
    digitalWrite(3, LOW);
    digitalWrite(2, LOW);
  } else if (lux >= 20 && lux < 2000) {
    lcd.print("Cahaya Redup ");
    digitalWrite(4, LOW);
    digitalWrite(3, HIGH);
    digitalWrite(2, LOW);
  } else if (lux >= 2000 && lux < 10000) {
    lcd.print("Cahaya Terang");
    digitalWrite(4, LOW);
    digitalWrite(3, LOW);
    digitalWrite(2, HIGH);
  } else {
    lcd.print("Lux Out of Range");
  }

  lcd.setCursor(0, 1);
  lcd.print("Lux: ");
  lcd.print(lux);

  Serial.print(" Lux: ");
  Serial.println(lux);
  
  delay(1000); // Beri waktu untuk melihat perubahan pada LCD
}