Hi all,
I finally got to upload a sketch on my arduino board, using two multiplexers, one with 16 analog potentiometers, and another one with 16 buttons. The sketch is all fine and I get the data in Pd, but every time I open the patch, the numbers from the knobs and buttons go to a different place. The Pd patch is like this

[comport 4 9600]
|
[zl group 32]
|
[unpack f f f f f f f f f f f f f f f f f f f f f f f f f f f f f f f f]
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |

The knobs are being sent in a row (although every time starting from a different place in [unpack]) and the buttons are being routed randomly. Any idea how to solve this?
I've attached the arduino sketch.

Thanks

http://www.pdpatchrepo.info/hurleur/my_mux2_analog_digital.ino

Looks like it settled down, routing analog values properly and buttons in some whatever row (except if it's some specific algorithm I'm unable of recognizing), but every time the same. I checked it four times, every time quitting Pd and unplugging and replugging the arduino and it works...Hope it stays like this.