The main additions (which are pretty cool) in version two of the Android Open Accessory protocol (AOAP) are support for: * Connection over Bluetooth in additio

The main additions (which are pretty cool) in version two of the Android Open Accessory protocol (AOAP) are support for: * Connection over Bluetooth in addition to USB * Audio over USB * USB HID capability (accessory can act as an input device) IMO the biggest issues with the original AOAP were the lack of device support, convoluted demo app implementation and lack of documentation. Very little has been done publicly with the platform as a result--which is unfortunate as it has great potential. Device support is slowly improving but there's still no easy way to know if any particular device has support for the protocol as there's no requirement for manufacturers to support it. For people coming from an Arduino background learning to code for Android is a huge learning curve and I think this acts as a disincentive for people to play with the technology. In light of this I created the "Handbag for Android" project which enables you to create Android accessories without writing Android code: * http://HandbagDevices.com/ http://HandbagDevices.com/ After installing the Handbag app on the phone/tablet you can create an Arduino sketch that describes the UI and this gets uploaded to the Android device each time the accessory is connected. Check it out if you'd like an easy way to get started with Android accessories. (Yesterday I gave the project some improved installation documentation and updated it for easy compatibility with recent Arduino releases.) I'm speaking about this project at OSCON in July: "Arduino & Handbag: Create Android Accessories Without Android Code" (http://www.oscon.com/oscon2012/public/schedule/detail/23946 http://www.oscon.com/oscon2012/public/schedule/detail/23946). If you're there come and say "Hi". :) (When the project gets AOA2 support depends on when I get my hands on a board. :) ) If you're coming from the Processing world I also recently worked with the Arduino team to simplify and improve the way to get started there too--documented at: * http://labs.arduino.cc/ADK/AccessoryMode http://labs.arduino.cc/ADK/AccessoryMode (BTW If you'd like to get started with Handbag, don't have a USB-capable Arduino but do have a network-capable Arduino get in touch--I might have an alpha release for you to test. :) )