Different ways to set the time on the DS1307 RTC

Projects Programming
1

Hi everyone, I have a DS1307 real time clock and I’m trying to figure how to set the time using time expressed as seconds. I’m using the RTClib library.

I know that I can set the time using this:

rtc.adjust(DateTime(2022, 08, 08, 12, 34, 56)); //set date-time manualy:yr,mo,dy,hr,mn,sec

but how can I set the time if the time I have is in seconds?

Time: 12:34:56 which equates to: 45296 (seconds)

Doing rtc.adjust(DateTime(45296)); doesn’t give the correct time.

2

Reverse the calculation so you get hours, minutes and seconds from the seconds value that you have. Next use rtc.adjust(DateTime(2022, 08, 08, hours, minutes, seconds)).

4

Hi,
try this code:

// Date and time functions using a DS1307 RTC connected via I2C and Wire lib
#include "RTClib.h"

RTC_DS1307 rtc;

char daysOfTheWeek[7][12] = {"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"};

void setup () {
  Serial.begin(57600);

#ifndef ESP8266
  while (!Serial); // wait for serial port to connect. Needed for native USB
#endif

  if (! rtc.begin()) {
    Serial.println("Couldn't find RTC");
    Serial.flush();
    abort();
  }
   unsigned long myUnixTime = 1659916800;  //Time in seconds from 1/1/1970 to today 0 h
   unsigned long mytimeSeg = (1234); //(time from 0 h to now in seg )
  //rtc.adjust(DateTime(2022, 8, 8, 0, 0, 0));
   myUnixTime = myUnixTime +   (mytimeSeg);  //(time from 0 h to now in seg )
   rtc.adjust(myUnixTime);
}

void loop () {
    DateTime now = rtc.now();
   
    Serial.print(" since midnight 1/1/1970 = ");
    Serial.print(now.unixtime());
    Serial.print("s = ");
    Serial.print(now.unixtime() / 86400L);
    Serial.println("d");

    Serial.println();
    delay(3000);
}
1 Like
5

Take a look at Unix time, it may have what you want.

1 Like
6

Thank you everyone. It looks like Unix time might be the way to go and I'm looking more into it now.

1 Like
7

Can you mark it solved. Thanks

8

Ola,
se seu problema foi resolvido, faça uma gentileza a todos do fórum, principalmente a quem te ajudou.
Escreva [Resolvido] antes do título do seu tópico, assim se alguém pesquisar e encontrar seu tópico saberá como é a solução.

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Hi,
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Write [Solved] before your topic title, so if someone searches and finds your topic, they'll know what the solution looks like.
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9

@ruilviana, English please, google translate is working overtime :smiley:

10

Sorry;

thanks for the alert.

11

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