I have an arduino Mega ADK board which I have been using with my Samsung Galaxy nexus. The board has worked just fine as a usb accessory but after the jellybean update, the board failed to connect with a could not read device protocol version. Is there something that I am missing or is this a bug that needs to be fixed?
Google changed Android Open Accessory protocol version in API level 16 ( >= 4.1). AOA in the new version (v2) is not backward compatible. I’m getting the same error on my MEGA ADK you got. Read somewhere that there is a newer version of Arduino ADK library that works with the new AOA and all you have to do is recompile your Arduino code.
Try out the lates adk version
http://developer.android.com/tools/adk/adk.html
I’m still trying to figure it out…