I have the impression that a lot of Udoo users do not use the Arduino part of their Udoo ( Dual/Quad/Neo/X86). I think a lot of them are used as a media server, desktop pc/tablet. That is a pity because it is one of the main unique features of these nice boards. If you are not using the Arduino part can you tell us why? Too complicated? Not needed after buying the board?
I always liked to have an arduino board directly connected to my pc/android device, that's way i've bought UDOO board (Quad before and now x86). I have to admit that i never played enough to do something really useful on the arduino side, but at least i am implementing the well known "ambilight clone" on my x86, which will be used mainly as a MediaCenter.
I'm eagerly awaiting the X86s to arrive, so that will free my Quad to replace my Neo in my project. The Arduino part of the Neo provides me with more struggles than I want. The Neos I have will be used in other places around my house, and I will use the Arduino part for that, sensing several environmental things. For the X86s, I have plans for at least one to use the Arduino part, though not as extensive as they can.