#include <LiquidCrystal_I2C.h>

#define LDR_PIN 2
LiquidCrystal_I2C lcd(0x27,20,4);

void setup() {
  pinMode(LDR_PIN, INPUT);
  lcd.init();
  lcd.backlight();
}

void loop() {
   lcd.setCursor(2,0);
  lcd.print("Room : ");
  if (digitalRead(LDR_PIN) == LOW) {
    lcd.print("Light!");
  } else {
    lcd.print("Dark ");
  }
  delay(100);
}