The Arduino Mega 2560 is a microcontroller board based on the ATmega2560. It has 54 digital input/output pins , 16 analog inputs, 4 UARTs , a 16 MHz crystal oscillator, a USB connection, a power jack, an ICSP header, and a reset button. It contains everything needed to support the microcontroller; simply connect it to a computer with a USB cable or power it with a AC-to-DC adapter or battery to get started. The Mega is compatible with most shields designed for the Arduino.The Mega 2560 is an update to the Arduino ADC, which it replaces. The Arduino Mega2560 has a resettable polyfuse that protects your computer’s USB ports from shorts and overcurrent.