This is Arduino compatible R3 Mega2560 ATmega2560-16TW (upgrade version) control board .This is an ATmega2560 as core microcontroller development board itself has 54 groups digital I / O input / output terminal (14 groups do PWM outputs), 16 sets of simulation than the input side, group 4 UARTs (hardware serial ports), using the 16 MHz crystal oscillator. With the bootloader, download the program directly via USB without having to go through other external writer. Supply part of the optional USB power, or as an external power using the AC-to-DC adapter and battery.