the arduino mega adk is a microcontroller board based on the atmega2560 (datasheet). it has a usb host interface to connect with android based phones, based on the max3421e ic. it has 54 digital inputoutput pins (of which 15 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.