The Arduino Mega ADK Rev3 was designed to work with Android. It is a combination of hardware and software designed to help people interested in designing accessories for Android devices.
The ADK Rev3 is based on the Mega 2560. It is compatible with Android’s Accessory Development Kit examples. It has 54 digital input/output pins (of which 14 can be used as PWM outputs), 16 analog inputs, 4 UARTs (hardware serial ports), a 16 MHz crystal oscillator, a USB connection, a power jack, an ICSP header, and a reset button.