Unlike most Arduino boards, the Arduino Due board runs at 3.3V. The maximum voltage that the I/O pins can tolerate is 3.3V. Applying voltages higher than 3.3V to any I/O pin could damage the board.
The board contains everything needed to support the microcontroller. Simply connect it to a computer with a micro-USB cable or power with an AC-to-DC adapter or battery. The Due is compatible with all Arduino shields that work at 3.3V and are compliant with the 1.0 Arduino pinout.
The Due follows the 1.0 pinout:
- TWI: SDA and SCL pins that are near to the AREF pin.
- IOREF: allows an attached shield with the proper configuration to adapt to the voltage provided by the board. This enables shield compatibility with a 3.3V board like the Due and AVR-based boards which operate at 5V.
- An unconnected pin, reserved for future use.