AVR-Chat

On Thu, 13 Jan 2005 11:13:34 -0300 (ART) you wrote:

>
>I am trying to make a ohm-meter using Atmega16.  The
>problem is that the ADC is reading values that change
>all the time (at least the five less significant bits
>change all the time).  I think there are several
>factors that affect the precision of the ADC.  Some of
>these factors are hardware related, an other has to do
>with the firmware.  I know the lower the ADC clock is,
>the better precision you get.  Also, the AD conversion
>can be done in sleep mode.  Any suggestions?

I get a rock steady ADC reading using AVR chips with 2 resistors on the input.
That is without sleep mode or an LC filter. That is using a 115.2KHz ADC clock.
Anything lower than 200KHz should be fine.

Perhaps you could post the code.
--
Ralph Hilton
http://www.ralphhilton.org
C-Meter: http://www.cmeter.org
FZAOINT http://www.fzaoint.net