ATmel MCU ATMEGA16U2 MEGA 2560 R3 Improved Version CH340G Board is a micro-controller board base on the ATmega2560. It has a USB host interface to connect with Android based phones, base on the MAX3421e IC.
It has 54 digital input/output 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. The MEGA ADK is base on the Mega 2560. Similar to the Mega 2560 and Uno, it features an ATmega8U2 program as a USB-to-serial converter. Revision 3 of the Mega ADK board has a resistor pulling the 8U2 HWB line to ground, making it easier to put into DFU(Device Firmware Upgrade) mode.