AVR-Chat

--- In AVR-Chat@yahoogroups.com, "smhodge" <stevehodge@...> wrote:

> ... additional current drains of
> the order of what the uC consumes ...

Ah, so the question is really how can you monitor a 12 volt source with 
a low voltage microcontroller while drawing less than a dozen 
microamps.  I'm not sure how all the op-amp ideas address that, but 
maybe they do.

> only need to sample very infrequently (like every second) so I could 
> use mosfets and another output pin to turn on the dividers only when 
> needed.

If a little compexity is acceptable, this could work.  You'd have to 
figure out exactly where to put the MOSFETS and how to drive their 
gates without getting back into the problem you're trying to get out of.

Graham.