#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C  lcd(0x27,16,2);

int i = -1;

void setup() {
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0,1);
  lcd.printstr("@");
}

void loop() {
  delay(500);
  lcd.setCursor(i,1);
  lcd.printstr(" ");
  lcd.setCursor(++i,1);
  lcd.printstr("@");
  if (i > 16) {
    i = -1;
  }
}