#include <RTClib.h> 
#include <Wire.h> 
#include <LiquidCrystal_I2C.h> 
RTC_DS1307 rtc;
LiquidCrystal_I2C lcd(0x27,16,2);  


void setup() {
  Wire.begin();
  rtc.begin();
  //rtc.adjust(DateTime(2023,1,11,15,30,0));
  rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
  lcd.init();

  if (! rtc.begin()) {//调试RTC
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("RTC Not Working");
  }
}

void loop() {
  DateTime now = rtc.now();
  
  lcd.setCursor(3,0);
  displayData(now.year());
  lcd.print('/');

  displayData(now.month());
  lcd.print('/');
  lcd.print(now.day());

  lcd.setCursor(4,1);
  displayData(now.hour());
  lcd.print(':');
  displayData(now.minute());
  lcd.print(':');
  displayData(now.second());

}

void displayData(u32 data)
{
  if (data < 10)
  {
    lcd.print(0);
    lcd.print(data);
  }
  else
    lcd.print(data);
}