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Analog In Noise?

Topic last updated 12 Jul 2012, by Brendan Dawes. 3 replies
Brendan Dawes
10 Jul 2012

I've connected a pot to p20 but the values coming back seem completely random, constantly jittering. As I turn the pot up the values do increase but they're always with other randomness. Also they value is nowhere near the range 0.0 to 1.0. I've read some posts about problems with Analog in but wasn't sure if things had been fixed since then.

I've tried the pot on an Arduino and it works perfectly with the range going from 0 - 1023.

Any ideas?

Brendan Dawes
10 Jul 2012

er... forget that - breadboard wiring error - I'll get my coat.

Chris Styles
12 Jul 2012

Hi Brendan,

There were a few issues. This was mostly solved in the software library by taking three samples and returning the median.

Since then, I did and investigation and found how to get the best ADC performance, which can be read all about here :

Cheers, Chris

Brendan Dawes
12 Jul 2012

Thanks Chris, though I realised I hadn't wired up the pot to 3.3v! Works really well now.