Introduction - If you have any usage issues, please Google them yourself
Android Open Accessory Mode is a feature of Android OS 3.1 (back portable to version 2.3.4) whereby an external USB host controller may enumerate the Android USB peripheral port and create a two way data port to allow external hardware to control the Android platform or for the Android platform to control external hardware. A typical application may be buttons, LEDs, or joystick as found on a games controller.