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

LiquidCrystal_I2C lcd(0x27, 20, 4);
const int ledPins[] = {11, 10, 9}, buttonPins[] = {A0, A1, A2};
int currentLED = 0, brightness[] = {0, 0, 0};

void setup() {
  LCD_setup(); Serial.begin(9600);
  for (int i = 0; i < 3; i++) pinMode(ledPins[i], OUTPUT);
  for (int i = 0; i < 3; i++) pinMode(buttonPins[i], INPUT_PULLUP);
}

void LCD_setup() {
  lcd.begin(40, 4); lcd.backlight();
  lcd.setCursor(0,0); lcd.print("LED Dipilih   : 1");
  lcd.setCursor(0,1); lcd.print("LED 1 Glow    : ");
  lcd.setCursor(0,2); lcd.print("LED 2 Glow    : ");  
  lcd.setCursor(0,3); lcd.print("LED 3 Glow    : ");
}

void loop() {
  static bool initialPrint = true;
  if (initialPrint) {
    Serial.println("TombolMerah   : Pilih LED");
    Serial.println("TombolKuning  : (-) PWM LED");
    Serial.println("TombolHijau   : (+) PWM LED");
    Serial.println(currentLED + 1); initialPrint = false;
  }

  if (digitalRead(buttonPins[0]) == LOW) {
    currentLED = (currentLED + 1) % 3;
    lcd.setCursor(0,0); lcd.print("LED Dipilih   : " + String(currentLED + 1));
    delay(300);
  }

  if (digitalRead(buttonPins[1]) == LOW) {
    brightness[currentLED] = max(0, brightness[currentLED] - 1);
    lcd.setCursor(0,(currentLED + 1));
    lcd.print("LED " + String(currentLED + 1) + " Glow    : " + String(brightness[currentLED]) + " ");
    delay(50);
  }

  if (digitalRead(buttonPins[2]) == LOW) {
    brightness[currentLED] = min(255, brightness[currentLED] + 1);
    lcd.setCursor(0,(currentLED + 1));
    lcd.print("LED " + String(currentLED + 1) + " Glow    : " + String(brightness[currentLED]) + " ");
    delay(50);
  }

  for (int i = 0; i < 3; i++) analogWrite(ledPins[i], brightness[i]);
}