Hello Zainul, Thanks for your reply. You said that the freq error (worst case) for the 32 Khz crystal is 40 ppm. What if we use the internal DCO ? will our internal freq error go up ?
Thanks, Somnath On Sat, Oct 18, 2008 at 3:35 PM, Zainul M Charbiwala <[EMAIL PROTECTED]>wrote: > Hi Somnath, > > The main clock on the Telos motes runs on an internal DCO which has a > lot of frequency error (could be on the order of 10%), unless the > error is corrected through periodic recalibration with the crystal. > > I believe the timers are run off the 32KHz crystal in TinyOS, which > would lead to a worst case of 40ppm freq error. > > The clock drift is essentially (in sec), drift = > (time_since_last_sync)*(freq_error_in_ppm)/1e6. > > This means that if you don't resync periodically, your clock drift > could be unbounded. > Hope this answers your question. > > Zainul. > > On Sat, Oct 18, 2008 at 1:17 PM, Somnath Mitra <[EMAIL PROTECTED]> wrote: > > Hello , > > > > People who have worked on time synchronization, can anyone please tell me > > that - > > > > Can we say that there is a maximum upper bound on the amount of drift of > the > > clocks of Telos like platforms ? > > > > Thanks, > > > > Somnath Mitra > > > > _______________________________________________ > > Tinyos-help mailing list > > [email protected] > > https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help > > >
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