#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0X27,16, 2);

void setup() {
  lcd.begin(16, 2);
  lcd.print("hello, world!");
}

void loop() {
  lcd.display();
  delay(500);
  lcd.noDisplay();
  delay(500);
}