#include <LiquidCrystal_I2C.h>

#define I2C_ADDR    0x27
#define LCD_COLUMNS 20
#define LCD_LINES   4

LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);

void setup() {
  // put your setup code here, to run once:
  lcd.init();
  lcd.backlight();
}

void loop() {
  // put your main code here, to run repeatedly:
  String sWrite;
  sWrite = "Hello, world!";
  lcd.setCursor(0, 0);
  for (long i=0; i < sWrite.length();i++) {
    lcd.print(sWrite[i]);
    delay(500);
  }
  lcd.clear();
}