[En-Nut-Discussion] AD conversion resolution?

[Kathy Quinlan]

Gerwin Voorsluijs wrote:

> Hi Kathy,
> 
> You mean it could be noise? That would not explain why I don't see such 
> jumps on my voltmeter, nor does it explain why I see this behaviour over 
> a number of sweeps. Btw I use the internal reference voltage on the 
> Ethernut.
> 
> In the mailing list I saw that you are also using the ADC function of 
> the Ethernut and I was wondering if you could look at the results you 
> are getting to see if maybe I'm unlucky and my Ethernut is broken?
> I know that on the total range of the 10bit ADC (1024 values) a jump of 
> 50 is not that big (roughly 5% ), but for what I want to use it for, it 
> is vital.
> 
> Cheers,
> 
> Gerwin
> 

You know that the internal ref is not accurate (or even close) a good 
external Vref is essential)

I have had ALOT of problems with the internal ref, and now only use 
external ones.

I would try to feed in an external Vref first.

Regards,

Kat.


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