# Problem with RTC

**URL:** <https://forums.digi.com/t/problem-with-rtc/8792>\
**Category:** Rabbit\
**Created:** [June 5, 2007, 10:09am UTC](https://forums.digi.com/t/problem-with-rtc/8792 "2007-06-05T10:09:03Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Taris](https://avatars.discourse-cdn.com/v4/letter/t/c4cdca/32.png) [@Taris](https://forums.digi.com/u/Taris)\
**Post date:** [June 5, 2007, 10:09am UTC](https://forums.digi.com/t/problem-with-rtc/8792/1 "2007-06-05T10:09:03Z")

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We have problem with real time clock (RCM3100). In some cases without power supply we have situation in wich RTC goes faster, approximately 15 min per one day.  
We try to short R2 resistor (see figure 1 in the technical note TN235) and it solved our problem. What problems in the future would we have with this solution?

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**Author:** ![User1080](https://avatars.discourse-cdn.com/v4/letter/u/bc8723/32.png) [@User1080](https://forums.digi.com/u/User1080)\
**Post date:** [August 28, 2007, 3:38am UTC](https://forums.digi.com/t/problem-with-rtc/8792/2 "2007-08-28T03:38:50Z")

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i have about the same problem with the RCM 3360… Everyday the RTC goes 15min ahead… But in my case, it is with external power supply…

Still looking for solutions…

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**Author:** ![MGaidica](https://avatars.discourse-cdn.com/v4/letter/m/43a26b/32.png) [@MGaidica](https://forums.digi.com/u/MGaidica)\
**Post date:** [September 4, 2007, 1:12pm UTC](https://forums.digi.com/t/problem-with-rtc/8792/3 "2007-09-04T13:12:24Z")

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A solution is to regulate the temperature of the rabbit IC for consitent clock cycles and then write an updater code that sets the RTC back 15 seconds everyday. Otherwise use an I2C or SPI RTC chip. These were the solutions we had come up with for our data logging needs.

-Matt