#include <LiquidCrystal_I2C.h>
#include <RTClib.h>
#define OnBoardLED 13
LiquidCrystal_I2C myLCD(0x27,20,4);
RTC_DS1307 myRTC;
void setup() {
pinMode(OnBoardLED, OUTPUT);
Serial.begin(9600);
Serial.println(" Hello ENE of RMUTI Khonkaen");
myLCD.init();
myLCD.backlight();
myLCD.setCursor(1,0); myLCD.print(" Worarat "); //แสดงชื่อ
myLCD.setCursor(8,0); myLCD.print(" Poomying "); //แสดงนามสกุล
myRTC.begin();
}
unsigned char Cx=0;
unsigned long PrevTime,NowTime;
DateTime RTC_Now;
void loop(){
NowTime = millis();
if(NowTime >= (PrevTime + 100)){
if(Cx==0) digitalWrite(OnBoardLED, HIGH);
else if(Cx==3) digitalWrite(OnBoardLED, LOW);
if(Cx == 9){
  Cx = 0;
  RTC_Now = myRTC.now();
  myLCD.setCursor(0,3); myLCD.print(RTC_Now.hour()); //แสดงเวลา
  myLCD.print(":"); myLCD.print(RTC_Now.minute());
  myLCD.print(":");myLCD.print(RTC_Now.second());
  myLCD.setCursor(10,3); myLCD.print(RTC_Now.day()); //แสดงวันเดือนปี
  myLCD.print("/"); myLCD.print(RTC_Now.month());
  myLCD.print("/");myLCD.print(RTC_Now.year());
}else Cx++;
PrevTime = NowTime;
}}