On Saturday 01 February 2003 07:21 am, you wrote:

Oops, that's what I get for typing in the dark.  ;-D  I accidentally=20
sent the previous post before I was finished being long winded.

I'm getting ready to implement the "very simple delta-sigma ADC" that=20
Dave Tweed thoughtfully explained to me a few weeks ago.  After=20
explaining it to my wife last night, I now comfortably understand the=20
theory.  ;-)  Does anyone else use that technique?

I am attempting to read the value of a pot. using the 628's comparator=20
and a TMR0 loop to sample the voltage at an R/C junction and compare=20
that to the voltage at the wiper of the pot.  The comparator output is=20
then fed to the R/C time constant thru the R and also "added" to a=20
counter.  This, AIUI, PWM's the R/C creating a matching voltage accross=20
the capacitor.  Every 256 loops, the counter is copied and cleared.  =20
Hopefully, this all results in a feedback loop that works to give me an=20
8 bit value representing the wiper position of the pot.  ;-)   If all=20
goes well, I should have that working today.

Does that sound about right?  Is there an easier/better way?

michael brown

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