Multiplexing arduino (a midi controller)

I would like to make a midi controller with 12 pots but Arduino has only 6 analog inputs. I have tried 4051b multiplexor (I can address 8 inputs using 3 Arduino’s digital outputs and 1 Arduino’s analog input).
So, because Arduino has 6 analog inputs, I’m going to use 6 multiplexors (one for each analog input) and the same 3 digital outputs to set multiplexor addresses.
When I made a test with one multiplexor I noticed that when I read the analog input it was noisy (for example 200 201, 199, 200, …) I’m very bad at electronics and I don’t know If noise will be a problem if I would use 6 multiplexors.
Any suggestion?

Thanks in advance


with the internal A/D converter(s) and 'breadboard' style wiring, I don't think you can do much better than the 'noisy' specs you give (i.e. 200, 199, 200, 201...).

Considering that the 5v range is represented by 1023 units, a unit of jitter is about .1% of the measurement, or 5mv... I think you will be hard pressed to get much better than about 1mv accuracy with this grade of chip, wiring, temperature control and fabrication.

That said, there is a tutorial in the Playground and her that show you how to hook up 63 sensors to the Arduino, and here:

You could also look into external high-precision A/D converters. There have been a few posts about these in the forum. Daniel