AVR-Chat

Yes, I always put in an external RC between any sensor and the
A-D input. It's a bargain in space and cost, taking advantage
of the high input impedance of the A-D (i.e.no opamp required).
Ken


> At 04:54 PM 9/11/05 -0700, Ken Holt wrote:
>>I second Larry's suggestion for using IIR filtering.  I use a sequence
>>of them for
>>my noisy accelerometer applications, (as well as other sense inputs),
>>and gain
>>flexible low-pass filtering and increased resolution.  They are very easy
>> to
>>implement in AVR.
>
> They may be easy to implement but you still need an external hardware
> filter.  Particularly if you have a 'noisy' signal and or impulse noise.
> A
> simple RC can give you a low pass sufficient to allow SW filtering to
> handle the rest but you must remove or at least reduce the frequencies
> above the Nyquist frequency.
>
> Robert
>
>
> " 'Freedom' has no meaning of itself.  There are always restrictions,   be
> they legal, genetic, or physical.  If you don't believe me, try to chew a
> radio signal. "  -- Kelvin Throop, III
> http://www.aeolusdevelopment.com/
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
>