Set the time with RtcDS1302 library

Using Arduino Programming Questions
1

Hi - I'm using the library at: https://github.com/Makuna/Rtc/tree/master/src
to display the time. The example code shows setting of the time from the current time. I need to set the time according to a user input (for a Nixie Clock project), so I'm looking at the function in the library code:

 void SetDateTime(const RtcDateTime& dt)
    {
        // set the date time
        _wire.beginTransmission(DS1302_REG_TIMEDATE_BURST);

        _wire.write(Uint8ToBcd(dt.Second()));
        _wire.write(Uint8ToBcd(dt.Minute()));
        _wire.write(Uint8ToBcd(dt.Hour())); // 24 hour mode only
        _wire.write(Uint8ToBcd(dt.Day()));
        _wire.write(Uint8ToBcd(dt.Month()));

        // RTC Hardware Day of Week is 1-7, 1 = Monday
        // convert our Day of Week to Rtc Day of Week
        uint8_t rtcDow = RtcDateTime::ConvertDowToRtc(dt.DayOfWeek());

        _wire.write(Uint8ToBcd(rtcDow));
        _wire.write(Uint8ToBcd(dt.Year() - 2000));
        _wire.write(0); // no write protect, as all of this is ignored if it is protected

        _wire.endTransmission();
    }

I'm battling to work out how I can use this function to set the individual hours and minutes:
Something like:

mymin = 10; // for example
myhour = 2; // for example
Rtc.SetDateTime(myhour, mymin)

I'm sure it's simple, but I'm not quite getting what to do at the top level of the code in my sketch.
Thanks and regards
Russell

2

That function takes a reference to a RtcDateTime object as its argument. You can find the definition of this class in RtcDateTime.h.

3

Thanks - but I suppose I don't really know what I'm doing: I tried this:

void setDs1302()
{
  char datestring[20];
  char setmonth = 9;
  char setday = 4;
  int setyear = 2021;
  char sethour = 8;
  char setmin = 23;
  char setsec = 0; 
  snprintf_P(datestring,
             countof(datestring),
             PSTR("%04u/%02u/%02u %02u:%02u:%02u"),
             setyear,
             setmonth,
             setday,
             sethour,
             setmin,
             setsec );

Serial.println(datestring);
Serial.println("setting...");
Rtc.SetDateTime(datestring);
}

In order to hard code a time/date for testing: but I just get this output:

2021/09/04 08:23:00
setting...
01/01/2000 00:37:34
01/01/2000 00:37:36
01/01/2000 00:37:38
01/01/2000 00:37:40
01/01/2000 00:37:42
01/01/2000 00:37:44
01/01/2000 00:37:46

edit:
I think I missed the ':' required the object format:
this post helped: https://forum.arduino.cc/t/solved-ds3231-set-date-time-manually/454709

4

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