Here is Microchip’s response to the Arduino based hardware for use with Google’s ADK.
Microchip has announced the release of the Microchip PIC24F Accessory Development Start Kit for Android™. This is a standalone board used for evaluating and developing electronic accessories for Google’s Android operating system for smartphones and tablets.
Microchip’s PIC24F Accessory Development Starter Kit for Android (part # DM240415) is available today for $79.99. The PIC32 Accessory Development Starter Kit for Android (part # DM320412) is expected to be available in the third quarter of 2011 for $79.99. The software library, which works with both kits, will be available soon from Microchip support.
Microchip PIC24 development kit for Android – [Link]