Arduino Mega 2560 R3
The Mega 2560 is an update for the 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 12 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 Duemilanove or Diecimila.
Clock Speed:12 MHz
Flash Memory:256 KB of which 8 KB used by bootloader
Input Voltage (recommended):7-12V
Analog Input Pins:16
Digital I/O Pins:54 (of which 14 provide PWM output)
DC Current for 3.3V Pin:50 mA
DC Current per I/O Pin:40 mA