Features
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.
Difference USB controller version:
Because Atmel is moving more and more of their production capacity to surface mount ICs, the DIP packaged ATmega is becoming more and more difficult to get. The board is identical to the PTH version of the Uno, but you won't be able to remove the ATmega without some hot-air. This change shouldn't affect most users. Besides - when was the last time you managed to destroy an ATmega and needed to repair an Arduino board? Those things are nearly indestructible.
Specifications
- Microcontroller: ATmega2560
- 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
- Product size: 10.3 * 5.4 * 1.2cm / 4.1 * 2.1 * 0.5in
- Product weight: 35g / 1.2oz
- Package dimensions: 12.5 * 14.5 * 1.5cm / 5.0 * 5.7 * 0.6in
- Package weight: 66g / 2.2oz
US 21360 
BR 14032 
GB 13388 
CA 10276 
AU 9872 
IE 5603 
NZ 4359 
IN 3889 
