apuntes_Arduino/RTC/set_hora/set_hora.ino

// Funciones de Hora y Fecha usando un RX8025 RTC conectado via I2C y libreria Wire
#include <Wire.h>
#include "RTClib.h"

RTC_DS3231 RTC; //Create the DS3231 object

char weekDay[][4] = {"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" };

//year, month, date, hour, min, sec and week-day(starts from 0 and goes to 6)
//writing any non-existent time-data may interfere with normal operation of the RTC.
//Take care of week-day also.
DateTime dt(2018, 3, 20, 21, 51, 0);

void setup (){
    Serial.begin(57600);
    Wire.begin();
    RTC.begin();
    RTC.adjust(dt); //Adjust date-time as defined 'dt' above 
}

void loop (){
    DateTime now = RTC.now(); //get the current date-time
    Serial.print(now.year(), DEC);
    Serial.print('/');
    Serial.print(now.month(), DEC);
    Serial.print('/');
    //Serial.print(now.date(), DEC);
    Serial.print(' ');
    Serial.print(now.hour(), DEC);
    Serial.print(':');
    Serial.print(now.minute(), DEC);
    Serial.print(':');
    Serial.print(now.second(), DEC);
    Serial.println();
    //Serial.print(weekDay[now.dayOfWeek()]);
    Serial.println();
    delay(1000);
}