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

LiquidCrystal_I2C lcd(0x27, 16, 2); // Ganti ke 0x3F kalau perlu

const int mqDigitalPin = 2;
const int buzzerPin = 7;

const int redPin = 3;
const int greenPin = 5;
const int bluePin = 6;

bool isCommonCathode = true;

void setup() {
  pinMode(mqDigitalPin, INPUT);
  pinMode(buzzerPin, OUTPUT);
  pinMode(redPin, OUTPUT);
  pinMode(greenPin, OUTPUT);
  pinMode(bluePin, OUTPUT);

  Serial.begin(9600);

  lcd.init();            // Penting: gunakan init(), bukan begin()
  lcd.backlight();       // Aktifkan lampu LCD
  lcd.setCursor(0, 0);
  lcd.print("Status Gas:");
}

void loop() {
  int statusGas = digitalRead(mqDigitalPin);

  if (statusGas == LOW) {
    Serial.println("🚨 Gas terdeteksi!");
    digitalWrite(buzzerPin, HIGH);
    setColor(255, 0, 0);
    lcd.setCursor(0, 1);
    lcd.print("Deteksi Gas!  ");
  } else {
    Serial.println("✅ Gas aman");
    digitalWrite(buzzerPin, LOW);
    setColor(0, 255, 0);
    lcd.setCursor(0, 1);
    lcd.print("Gas Aman        ");
  }

  delay(500);
}

void setColor(int r, int g, int b) {
  if (!isCommonCathode) {
    r = 255 - r;
    g = 255 - g;
    b = 255 - b;
  }
  analogWrite(redPin, r);
  analogWrite(greenPin, g);
  analogWrite(bluePin, b);
}