AVR-Chat

On Thu, 29 Jul 2004, Dave Mucha wrote:

> Depending on the external value, you might need to use an op-amp to
> change the value to get it to read so the highest voltage is the same
> as the chips voltage.    This means that if you are running on 3
> volts and the thing you want to read is 0 to 10 volts, you can use a
> a voltage divider to change that to 0 to 3 volts.  But, if you want
> to measure 0 to 100mV,then you need to ampliphy the value and for
> that an op-amp would be called for.
>
> Since you mentioned external components, this may be on of those that
> would be needed.   But it would be needed for any style ADC you
> chose.

What method do you recomend for sourcing +V and -V to the opamp?

Rodrigo