27 responses to “Syncing DS1307 RTC with timeserver”

  1. paul

    great setup , will this sketch work on the latest IDE version 1.01 or do i need an older version for it,I know nothing abt programming

    if you are syncing time from a time server why do you need the RTC ( this is not a moan) just interested , i want to get a sketch running like yours , how do i call the data from the sd to a webserver , or can the sketch be changed to do this fronm the arduino.


  2. paul

    i have copied your sketch, but i get a few errors all the libs seem to be there i am using version 023 , could you point me in the right direction , the errors are below , could it be the wrong version of libs , i had trouble finding them , sorry to be pain.

    sketch_jul07a.cpp:17:17: error: dht.h: No such file or directory
    sketch_jul07a:34: error: ‘dht’ does not name a type
    sketch_jul07a.cpp: In function ‘void setup()’:
    sketch_jul07a:67: error: ‘class RTC_DS1307’ has no member named ‘isrunning’
    sketch_jul07a.cpp: In function ‘void loop()’:
    sketch_jul07a:91: error: ‘DHT’ was not declared in this scope
    sketch_jul07a:151: error: ‘DHT’ was not declared in this scope
    sketch_jul07a:259: error: ‘DHT’ was not declared in this scope

  3. paul

    many thanks


  4. boez52

    Would this work with a ChronoDot RTC??

  5. Boez52

    I see in a previous comment that this sketch does not work in the new arduino IDE…. Why is this?

  6. boez52

    Could you post the new sketch or email it to me?

  7. ADP

    I am also interested in the revise sketch because I have an Arduino Mega 2560, could you please post the new sketch or email it to me?

  8. hans

    Great job getting this together. It works fine but (for me) not with the timeserver (81, 95, 126, 170) (cannot ping it).

    Works fine with
    byte timeServer[] = {192,53,103,108}; // ptbtime1.ptb.de

    Is the be.pool.ntp.org a reliable server ?

    Hans Gent – OVL

  9. Ignacio


    great article, very helpful 🙂 Just one question: Are you using a battery with your DS1307? Shouldn’t that fix the precision issue?


  10. insippo

    All ok but……….. How and where to connect RTC ?

  11. insippo

    I found ds3234

  12. martin


    when i will change the timezone to UTC+01:00, what i have to change?

  13. Gtr_Stitch

    Hi there…quick and simple…where did you obtain the DallasTemperature library? I’ve tried one off the Arduino site, and it doesn’t exactly work. Not compiling. I haven’t found much in the way of reliability for the DS18B20. May just stick with the LM35.

  14. Will Parks

    Beautiful code. I have been looking for years for a way to get the Arduino to be able to connect and get info from Ethernet (settings and such)and while being able to log into to see current stats and download a data log file. and I just now stumbled across this. this will help get my project finally off the ground.

  15. Offer


    Thanks you so much for this code and setup.
    It seems a very old article, and I think – what had changed since than?
    Is a new RTC chip more accurate?
    Will memore limitations solved, or there is any way to run this on a latest Arduino IDE?

    I’ll really appreciate any ‘updated’ update.
    Many thanks!!

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