On Sun, Aug 1, 2010 at 12:21 AM, Rob Hamerling <[email protected]>wrote:
> > Hi Matt, Eur, > > > On 08/01/10 12:24 am, Eur van Andel wrote: > >> On 31 Jul 2010, at 22:08 , mattschinkel wrote: >> > > Good job on the RTC lib Rob. How accurate is it? >>> >> > I assume that the accuracy of the builtin RTCC module is 100% accurate! I > didn't see any Errata for this. > The longest time I have had my test-board running is about 30 hours. After > that the deviation was a few seconds. But I suppose this is caused by the > crystal (a 32768 Hz watch crystal). It's only about the crystal. My RTCC with 32KHz watch crystal it's less accurate (without any correction) than the zero error bresenham method with correction. On 30 days with ambient temperature variation between 20 and 38C, the error is higher than 150 seconds (about 5 seconds per 24 hours), with reference time being the PC clock (which is a bad reference anyway). The biggest advantage of the RTCC is that you can generate multiple counters counting time for different processes while the TMR0 with bresenham can be used for precise low frequency generation and/or PWM (0Hz-500Hz). Vasile -- You received this message because you are subscribed to the Google Groups "jallib" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/jallib?hl=en.
