On Wed, Dec 10, 2003 at 03:29:56PM +1100, Daniel wrote:
> I am looking for code (or PIC programming help) for a clock with
> calendar and one channel controller.

I've done a clock, I didn't need a calendar, but it would be easy to
add.  I don't know what a one channel controller is.

> I am considering using a DS1307 RTC and 16F84 PIC or similar. It will be
> used outdoors, battery powered with no mains reference. The accuracy
> needs to be as accurate as possible but no more than ? 2 minutes per
> month.

There's a big PIC clock kit around.  It uses 16F84 and big LED displays.
It doesn't use an RTC but is reasonably accurate, when tuned for it.

> I have read that a RTC chip does not necessarily ensure better accuracy
> or stability. Should it all be done in the PIC?

If you do it in the PIC, then your code can adjust the accuracy.  In an
RTC, you have to manually tweak the oscillator it uses.  If it has one
built in, then the data sheet should tell you how well trimmed it is.

> I need to switch at specific times on certain days, plus it needs
> compensation / adjustment for daylight saving times.

Sounds like familiar requirements.  I've done summer time adjustments.

http://quozl.linux.org.au/alarm-clock/

--
James Cameron    mailto:quozl@us.netrek.org     http://quozl.netrek.org/

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