Overview
The Arduino Mega 2560 is a microcontroller board based on the ATmega2560 (datasheet). It has 54 digital input/output pins (of which 15 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.

The Mega2560 differs from all preceding boards in that it does not use the FTDI USB-to-serial driver chip. Instead， it features the ATmega16U2 (ATmega8U2 in the revision 1 and revision 2 boards) programmed as a USB-to-serial converter.
Revision 3 of the board has the following new features:
  • 1.0 pinout: added SDA and SCL pins that are near to the AREF pin and two other new pins placed near to the RESET pin， the IOREF that allow the shields to adapt to the voltage provided from the board. In future， shields will be compatible both with the board that use the AVR， which operate with 5V and with the Arduino Due that operate with 3.3V. The second one is a not connected pin， that is reserved for future purposes.
  • Stronger RESET circuit.
  • Atmega 16U2 replace the 8U2.

Specifications

Microcontroller ATmega2560
Operating Voltage 5V
Input Voltage (recommended) 7-12V
Input Voltage (limits) 6-20V
Digital I/O Pins 54 (of which 15 provide PWM output)
Analog Input Pins 16
DC Current per I/O Pin 40 mA
DC Current for 3.3V Pin 50 mA
Flash Memory 256 KB of which 8 KB used by bootloader
SRAM 8 KB
EEPROM 4 KB
Clock Speed 16 MHz

Programming

The Arduino Mega can be programmed with the Arduino software， which can be downloaded from the following site:
http://arduino.cc/en/Main/Software
Select "Arduino Mega 2560 from the Tools > Board menu (according to the microcontroller on your board). Select the serial device of the Arduino board from the Tools > Serial Port menu. This is likely to be COM3 or higher (COM1 and COM2 are usually reserved for hardware serial ports).

For the language reference， see the following sites:
http://arduino.cc/en/Reference/HomePage
http://arduino.cc/en/Tutorial/HomePage

Installing drivers for the Arduino Mega 2560 with Windows7， Vista， or XP:

  1. Plug in your board and wait for Windows to begin it's driver installation process. After a few moments， the process will fail， despite its best efforts
  2. Click on the Start Menu， and open up the Control Panel.
  3. While in the Control Panel， navigate to System and Security. Next， click on System. Once the System window is up， open the Device Manager.
  4. Look under Other Devices. You should see a device named "Arduino Mega 2560"
  5. Right click on "Arduino Mega 2560" and choose the "Update Driver Software" option.
  6. Next， choose the "Browse my computer for Driver software" option.
  7. Finally， navigate to "Arduino-1.0.x\drivers" (not the "FTDI USB Drivers" sub-directory).
  8. A diaglog box with warning will pop out， select "Install this driver software anyway"
  9. Windows will finish up the driver installation from there.