//thêm thư viện
#include <LiquidCrystal.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal lcd (13, 12, 11, 10, 9, 8, 7, 6, 5, 4);
// LiquidCrystal lcd (RS, EN, D0, D1, D2, D3, D4, D5, D6, D7);
// LiquidCrystal lcd (RS, RW, EN, D0, D1, D2, D3, D4, D5, D6, D7);
// LiquidCrystal lcd (RS, EN, D4, D5, D6, D7);
// LiquidCrystal lcd (RS, RW, EN, D4, D5, D6, D7);
LiquidCrystal_I2C lcd_i2c (0x26, 20, 4);
LiquidCrystal_I2C lcd_i2c2 (0x11, 20, 4);
// LiquidCrystal_I2C lcd_i2c (i2c_address, 20, 4);
unsigned long now = 0;

void setup() {
  // put your setup code here, to run once:
  lcd.begin(20, 4);
  lcd.print("WELCOME!");
  // lcd.print("hello!");
  lcd.setCursor(0, 1);
  lcd.print("AS");
  lcd_i2c.init();
  lcd_i2c.backlight();
  lcd_i2c.print("WELCOME!");
  lcd_i2c.setCursor(0, 1);
  lcd_i2c.print("AS");
  lcd_i2c2.init();
  lcd_i2c2.backlight();
  lcd_i2c2.print("WELCOME!");
  lcd_i2c2.setCursor(0, 1);
  lcd_i2c2.print("AS");
  delay(5000);
  lcd.clear();
}

void loop() {
  // put your main code here, to run repeatedly:
  // lcd.display();
  // lcd_i2c.display();
  // delay(500);
  // lcd.noDisplay();
  // lcd_i2c.noDisplay();
  // delay(100);
  lcd.home();
  lcd.print("current runtime:");
  lcd.setCursor(2, 1);
  lcd.print(millis());
  if (millis() - now > 1000) {
    lcd.setCursor(0, 2);
    lcd.print("random num: ");
    lcd.setCursor(12, 2);
    lcd.print(random(0, 10));
    lcd.print(" ");
    now = millis();
  }
}