> The RC circuit is not the most stable part of the PIC but it
> should be repeatable. It varies with temperature and, even
> with a trimmer, it wouldn't pay to use the PIC under those
> circumstances for any long-string comms that require
> precise timing. It should be OK for apps where periodic
> synching can be done though

Yeah thats what I reckon too. I gave up on 32kHz crystals on a
recent project because I had trouble getting the right capacitors to
make them start and then two of them failed in service. No doubt
there would be a way to overcome these problems, but the RC
option suddenly came to mind as cheap and reliable, and accuracy
didn't matter. In this case with RC oscillator at 25kHz the circuit
uses about 10uA more than with xtal at 32kHz.

Brent Brown
Electronic Design Solutions
16 English Street
Hamilton, New Zealand
Ph/fax: +64 7 849 0069
Mobile/text: 025 334 069
eMail:  brent.brown@clear.net.nz

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