XCSOURCE ATmega2560-16AU ATMEGA16U2 Board + Ethernet Shield W5100 Network Expansion TE168 The Mega 2560 is an update for the Arduino Mega, which it replaces. The board is a microcontroller board based on the ATmega2560-16AU . 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. 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 Duemilanove or Diecimila.