There, you see, finally Olin made sense of my addled attempt at answering
the OP's question.  Thanks, Olin.  Yes, if you amplify the original signal
you get *higher* resolution relative to the original signal.  In a project
just recently finished we had to divide a higher (0-20V) input signal by
4, which gives you *lower* resolution relative to the original signal.
OK, did I finally get it right?  8-P

Damn, it's a good thing I'm not actually working on a PIC project right
now, I could blow the house up.  Two weeks off work to move into a new
house is counter-productive - you get no "vacation" from work, and there's
two weeks' worth of crap waiting when you return to work as well.  That
and being away from my bench and the projects for even longer and the rust
rally sets in, doesn't it?

Dale
--
Hallo, this is Linus Torvalds and I pronounce Linux as Leennuks.
Hallo, this is Bill Gates and I pronounce 'crap' as 'Windows'.

On Thu, 11 Oct 2001, Olin Lathrop wrote:

> > Sorry, you're right -- the ADC step itself doesn't double, its
> > relationship to the original signal, which is half of Vref, does.  Now
> > you're taking 1023 steps to measure twice the original signal, rather than
> > 512 steps to measure the original signal.  It's the same thing, isn't it?
>
> If you multiply the original signal by 2 and use a Vref of 2V, you are
> taking 1023 steps to measure the whole original signal.

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.