At 09:44 PM 3/13/2006 -0500, you wrote:

>Now for the problem =AD A 60Hz wave has a period of 16.66ms, so half a wave
>would be 8.33ms.  If we divide this time into 256 slices that would give us
>32.5 us per slice.  A PIC16F87x running at 20MHz can perform an instruction
>in 200ns.  So at 200ns/per instruction we could perform 162 instructions in
>32.5us.  This is not enough time to go through all 255 steps in the look up
>table.  I could reduce the steps to 7 bits (128 steps) and this would
>possibly give me enough time for the look up table, but no much else.
>
>So as I said =AD anyone else already been through this that can possibly g=
uide
>me in a better method?  I am trying to hold external hardware down to a
>minimum.

Use two CCP modules, pin change on match. If you really want 256 linearized
steps you're going to have more raw time steps. Maybe 1,000 or more.

>Best regards,

Spehro Pefhany --"it's the network..."            "The Journey is the rewar=
d"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com
->> Inexpensive test equipment & parts http://search.ebay.com/_W0QQsassZspe=
ff



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