i have been connecting a hot hand 3 receiver to the axoloti via a 4 pole 3.5mm jack. the wiring is here:
so basically you supply 3.3v and gnd and get a wireless two axis controller back (3 but only 2 at a time available over the analog lines)
this thing really rocks for dubstep bass! i am still adapting the axoloti software side to accommodate for different fx controls (on/off, gradual etc.)
so if you see a used one of these pick them up!
also i would be very interested if somebody on here has a hot hand usb (a usb midi device that pairs with a hot hand ring) and could tell me if there are any latency issues with that. the hot hand 3 receiver directly to the analog ins of the axoloti works great and has no latency issues at all, but the usb solution would be nice for the future maybe.