title: Connect two android devices via USB
body: <p>I'm trying to figure out how to connect two Android powered devices,
  namely a smartphone (Android 4.1.2) and an android developer 
  board (Android 4.0.4) with apps running on each, via USB and get them 
  to communicate with each other.
  Right now the developer board is running as the host and the phone as
  an accessory. The hosts app is searching for connected devices and is
  able to identify the phone as a device, but the app running on the
  phone isn't able to find the host.
  I've searched the web for quite a while now (!!) but I didn't come 
  up with anything helpful yet that solved my problem.
  For my project it is crucial that I use an USB connection, so please
  don't propose that I use bluetooth, WiFi, or anything else...
  Regards</p>