Arduino Mega 2560 is the new sucessor to Arduino Mega 1280. Just released!
Arduino is an open-source physical computing platform based on a simple i/o board and a development environment that implements the Processing/Wiringlanguage. Arduino can be used to develop stand-alone interactive objects or can be connected to software on your computer (e.g. Flash, Processing, MaxMSP). The open-source IDE can be downloaded for free (currently for Mac OS X, Windows, and Linux).
The Arduino Mega 2560 is a microcontroller board based on theATmega2560. 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.
Input Voltage (recommended）
Input Voltage (limits)
Digital I/O Pins
54 (of which 14 provide PWM output）
Analog Input Pins
DC Current per I/O Pin
DC Current for 3.3V Pin
256 KB of which 4 KB used by bootloader