On 11-Feb-02 Ted Mawson wrote:
> I've been looking at the Weeder Frequency counter on the PIClist archives.  I
> called Weeder today and they no longer do the kit or any part of it.
>
> Questions:
>
> 1.    Is there anywhere else that has the kit in stock or even just the PCB?
> 2.    It looks like the original ran on a 4MHz crystal; if we used a 20MHz
> clock, couldn't we increase the max frequency capability?  Has anyone done
> this already?

OPSE didn't answer this question.

The PIC clock rate does NOT determine the maximum frequency that can be
measured.  The input signal is used to drive a hardware counter in the PIC.
A higher PIC clock won't actually give you any advantage in either the range or
the accuracy of the displayed frequency....

Hmmmmmm,...... Thinking about it.... A higher PIC clock MAY give better
accuracy as the jitter in interrupt latency will be reduced.  I run my 16F877
freq counter from a 14.7something Mhz crystal to get an accurate 0.1s timebase
using the maximum count (256) in Timer0.

I posted some code here a few weeks ago that may help you if you decide to
D-I-Y.

Peter Onion.

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