#include <Wire.h>  // Include the Wire library for I2C communication
#include <LiquidCrystal_I2C.h>  // Include the LiquidCrystal_I2C library

LiquidCrystal_I2C lcd(0x27, 16, 2);  // Replace 0x3F with the address of your I2C LCD module

void setup() {
  lcd.init();                      // Initialize the LCD
  lcd.backlight();                 // Turn on the backlight
  lcd.setCursor(0, 0);
}

void loop() {
  // Your main code here

  // To turn off the backlight
  lcd.noBacklight();
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Backlight Off");
  delay(1000);  // Wait for a second with the backlight off

  // To turn on the backlight
  lcd.backlight();
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Backlight On");
  delay(1000);  // Wait for a second with the backlight on
}