so by applying 3v to the aref pin, that's the value that the analog in is checked against? Then it's a matter of setting the refns bits to understand that it's 3v in or to at least check against the ref? Am I following this correctly?
Basically I've got a sensor giving me 0-3v based on it's reading.. if the ref voltage of the analog in is 5v, then I'm only using 2/3rds of the potential resolution of the input. I'd like this reading to be as accurate as possible so either I get my reading coming in to be 0-5v or I drop the ref voltage somehow to 3v. Though now that I'm saying that, it will limit me in the future if I have additional 5v sensors attached to the arduino...which may happen.
so would this just be done w/ an amplifier, like an lm386?
Sorry for the basic nature of these questions, I'm much more of a software hack than the nitty gritty hardware action...
Thanks!
-jf