add analog inputs to arduino duemilanove??

Forum 2005-2010 (read only) General Frequently-Asked Questions
1

Hello all-

I am wondering if it is possible to add additional analog inputs to the arduino duemilanove - I need to add 2 for a total of 8 (for pots)... I see the arduino mini has 8 analog inputs and I was hoping that there is an easy way to add additional inputs to the duemilanove. Any suggestions?

Thanks.

2

The surface mount package version of the ATmega168 has 8 analog inputs, and there are arduino clones that use that package.

The seeeduino at seeedstudio.com/depot uses that package. It gives you the 2 extra analogs as analog pins 6 and 7.

3

Analog multiplexer/demultiplexer:
http://www.arduino.cc/playground/Learning/4051

4

That's a good idea. I could use that chip on my projects. Thanks AlphaBeta. Does anyone have experience with that chip regarding switching time and noise (cross-talk, offset, drift etc.)? I was about to suggest some mechanical relays. They're slow and could irritate your ears but they are physically the closest to having multiple wires hooked up to one input. On the other hand, arduino only has 10bit accuracy so a small (5mV) offset is ok.

5

Does anyone have experience with that chip regarding switching time and noise

Nothing to remotely bother you at 10 bits.

6

thanks for the replies. i will check out the multiplexer(demultiplexer) 4051. i think it will work fine for what i have in mind.

7

you might want to check my 16 slide pot project:

http://mikmo.dk/misc/arduinomux.zip

8

@ MikMo

very cool! even a pcb layout - nice.

my goal is to build a sequencer for circuit bent applications - it seems you have worked hard on similar things. i will investigate your site more when i get some more time. my work is at: www.fauxaudio.net

thanks for posting the link.