> Kevin wrote:
> >> Kevin wrote:
> >>> This part.
> >>> Two poles of LPF each with 8 shift bits per pole settles to about 93%
> >>> in 1100 iterations.
> >>> especially since shifting by 8 bits is particularly trivial,
> >>> and 2 x 8 bits is a lot of random noise attenuation.
> >>
> >> There are a lot of statements in there, so again it's not clear what
> >> specifically you are asking about.
> >>
> >> I guess the only choice is to start at the beginning.  The "two poles
> >> of LPF" means two low pass filters concatenated.  This would be like
> >> two RC filters with a buffer in between them.
> >>
> >> Better answers require better questions.
> >
> > I guess it falls into the I don't know what I don't know
> > category. I'll check out a book and post a more direct
> > question in the future.
>
> Or you could say what specifically you want clarification on.
> Do you not  understand what is meant by two poles?

Yes, what is meant by two poles ?

>By shifting 8 bits?
I understand how to shift 8 bits, but why ?
Normally, I would take 50 10bit adc readings, add them and
then divied by 50 to get an average result.

What is settling time ?
I believe it is the time needed in between AD readings.
You said previously 1ms. is more that adequate between
successive ADC readings.

Yes How is 93% arrived at and what is it's significance?

What an iteration is?
A computational procedure in which a cycle of operations is
repeated, often to approximate the desired result more
closely. >>> from dictionary.com

Why 1100 iterations?
I assume based on the original discussion, he had time to
perform this many reads of the ADC while performing other
tasks.

Why shifting by 8 bits is particularly trivial?
I assume it has something to do with a bit mask,
Or is achieved by a single instruction ?

Why is 2 x 8 bits a lot of random noise attenuations?

> What is meant by random noise?
I understand random noise.


TIA,
Kevin

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist