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

// Set the LCD address to 0x27 and dimensions to 16x2
LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup() {
  pinMode(9, OUTPUT);
  
  // Initialize the LCD
  lcd.init();
  lcd.backlight();

  lcd.setCursor(0, 0);
  lcd.print("Pot:         ");
  lcd.setCursor(0, 1);
  lcd.print("Brightness:   ");
}

void loop() {
  int pot = analogRead(A0);  // 0 to 1023
  int brightness = map(pot, 0, 1023, 0, 255);
  int brightnessPercent = map(brightness, 0, 255, 0, 100);

  analogWrite(9, brightness);

  // Display potentiometer value
  lcd.setCursor(5, 0);
  lcd.print("    ");  // clear old value
  lcd.setCursor(5, 0);
  lcd.print(pot);

  // Display brightness percentage (always 3 digits with %)
  lcd.setCursor(12, 1);
  if (brightnessPercent < 10) lcd.print("  ");        // 1 digit
  else if (brightnessPercent < 100) lcd.print(" ");   // 2 digits
  lcd.print(brightnessPercent);
  lcd.print("%");

  delay(200); // Refresh quickly
}