Byron A Jeff wrote:

>But if the frequency of what is counted is a lot higher than the frequency of
>the PIC then you cannot have precise control over the precision of the counts.
>No to within one pulse. Say you have a frequency that's 8 times faster than
>the PIC. The accuracy of the count you get will only be within 8 pulses of
>the actual number of pulses due to the slowness of the PIC's clock. So would it
>then not be better to simply prescale the pulses by 8 and let the PIC count
>the results?

Using the prescaler with TMR0 makes a 16 bit counter which is essentially
independent of the PIC core.

Using the PIC core to generate the gate signal can be very deterministic.
If you make a loop that consumes 100,000 clock cycles, you will create a 100
mS gate (assuming 4.00 MHz crystal) with accuracy determined by the crystal
used.

In other words, this can function exactly like my old Fluke 1900A does.

dwayne


Dwayne Reid   <dwayner@planet.eon.net>
Trinity Electronics Systems Ltd    Edmonton, AB, CANADA
(403) 489-3199 voice          (403) 487-6397 fax

Celebrating 15 years of Engineering Innovation (1984 - 1999)

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