AVR-Chat

--- In AVR-Chat@yahoogroups.com, Dave VanHorn <dvanhorn@d...> wrote:
> At 09:53 AM 11/2/2004, Larry Barello wrote:
> 
> >Place a capacitor between Aref and ground (the analog ground).
> >
> >The accuracy of the conversion is better than .5%, but depending 
upon your 
> >VCC accuracy, your absolute accuracy won't be so good.  At room 
> >temperature most +5v regulators are pretty good, but you 
definitely won't 
> >get the accuracy over temp without an external, calibrated 
reference.
> 
> On the tiny-26, I got Vref values of 2.7V. Not very encouraging. We 
used an 
> external ref.

any suggestions on what to use for an external ref ?

I used a TI chip, the TLS2543, 11 channel 12 bit ADC chip and also 
found that unless the actual Vcc was corrected for, there were errors.

The guy who I was working with put a 0.01uF to ground on each input 
as a means to reduce the noise.

I'm curious what people who acutally know the right way to do things 
would do.


Dave