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rtc time lag

Discussion in 'General Electronics Chat' started by kppp, May 30, 2008.

  1. kppp

    Thread Starter Member

    Apr 23, 2008
    hello everyone;
    i m using rtc ds1307 and battery maxell cr2032 of 3volt
    i hav written software for displaying time and date
    s/w is working fine and h/w is also proper as per datasheet of ds1307
    my date is updated every day but my time lags
    even if i set the time, it works for some time and after that it again lags
    is it a problem of s/w or any h/w fault
    if h/w then pls suggest the change
    thank u all:)
  2. hgmjr

    Retired Moderator

    Jan 28, 2005
    The main source of a time drift error would be the clock source used on the RTC. Have you check to make sure that the clock frequency is correct? Any deviation from the specified frequency will through the accuracy off.

  3. AlexR

    Well-Known Member

    Jan 16, 2008
    Have you got the right type of crystal?

    32.678KHz watch crystals come for either 6pF and 12pF load capacitance. The DS1307 needs the 12pF crystal.