On the subject of resolution, if you save data every minute, be aware that =

power may be switched off after the count is virtually xx:xx:59 seconds.  O=
n =

power-up, it will start counting again from 0, so you lose 59 seconds of =

value.

In my app, I actually save data 10 times more than I the resolution present=
ed =

on the display, to minimize the effects of this.

Another option is to write the data internally to EEPROM when the count =

reaches xx:xx:30 seconds, assuming that it will get to the whole minute.  I=
f =

power is lost, it will effectively add up to 30 seconds in some cases, or =

lose up to 30 seconds in other cases.  Mathematically it should average out =

over time to minimize the total error.  At least, the theory seems good to =

me :-)

Cheers,
-Neil.


On Wednesday 31 May 2006 06:09, Peter Feucht wrote:
> Hello,
>
> Yes, it was somewhat misunderstandable....
>
> Total time is 5 years, means there may occur no overflow, even if the
> device is started (e.g.) 250 times a day every day.
>
> Resolution means, that it is acceptable that no count happens if the devi=
ce
> is only switched on for 10 seconds or so.
> Operation time=3D1'10" results in +1', operation time=3D10'55" results in=
 +10'
> and operation time=3D0'34" results in +0'.
>
> Will check the thread you spoke of.
>
> Thanks for all help!
>
> Regards
>
> Peter
>
>
> -----Urspr=FCngliche Nachricht-----
> Von: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] Im Auftrag
> von Jinx
> Gesendet: Mittwoch, 31. Mai 2006 12:34
> An: Microcontroller discussion list - Public.
> Betreff: Re: [PIC] operation time counter
>
> > > > The total time to be checked is 5 years and the resolution has to
> > > > be 1 minute.
> > >
> > >You simply won't get that accuracy over 5 years with a PIC's TMR. An
> > >external timing source is needed
> >
> > AFAICT the OP only requires a resolution of 1 minute, not an accuracy
> > of 1 minute in 5 years
>
> Hi Mike, if that were the case then the "5 years" is irrelevant. You may =
as
> well take the reading for the day and start afresh
>
> If the OP would care to enlighten us.........
>
> --
> http://www.piclist.com PIC/SX FAQ & list archive View/change your
> membership options at http://mailman.mit.edu/mailman/listinfo/piclist

-- =

http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist