/*
  https://github.com/Makuna/Rtc
  Arduino Real Time Clock library.
*/

#include <SoftwareWire.h>  // must be included here so that Arduino library object file references work
#include <RtcDS3231.h>

SoftwareWire myWire(6, 5); // SDA, SCL
RtcDS3231<SoftwareWire> Rtc(myWire);

void setup() {
  Serial.begin(9600);
  Rtc.Begin();

  //RtcDateTime compiled = RtcDateTime(__DATE__, __TIME__);
  //Rtc.SetDateTime(compiled + 0*60*60 + 8);

  //Rtc.SetDateTime(RtcDateTime(2018, 1, 17, 7, 53, 00));
}

void loop() {
  static char date[11];
  static char time[9];

  RtcDateTime dt = Rtc.GetDateTime();
  bool rtclock_err = !Rtc.IsDateTimeValid();

  snprintf(date, 11, "%04u-%02u-%02u", dt.Year(), dt.Month(), dt.Day());
  snprintf(time, 9, "%02d:%02d:%02d", dt.Hour(), dt.Minute(), dt.Second());

  Serial.print(date);
  Serial.print(" ");
  Serial.print(time);
  if (rtclock_err) Serial.print(" rtclock ER");
  else Serial.println(" rtclock OK");
  Serial.println("");

  delay(300);
}