ARDUINO DUE WITHOUT HEADERS is a microcontroller board based on the Atmel SAM3X8E ARM Cortex-M3 CPU. It is the first Arduino board based on a 32-bit ARM microcontroller. It has 54 digital input/output pins (of which 12 can be used as PWM outputs), 12 analog inputs, 4 UARTs (hardware serial ports), an 84 MHz clock, a USB OTG compatible connection, 2 DACs (digital to analog), 2 TWIs, a power jack, an SPI header, a JTAG header, a reset button and an erase button.
Warning: unlike most Arduino boards, the Arduino Due board operates at 3.3 V. The maximum voltage that the I/O pins can tolerate is 3.3 V. Applying voltages higher than 3.3 V to any I/O pin could damage the board.
The board contains everything needed to support the microcontroller; simply plug it into a computer with a micro-USB cable or power it with an AC/DC adapter or battery to get started. The Arduino Due is compatible with all Arduino Shields that run on 3.3V and are compatible with the Arduino 1.0 pin out.
Arduino Due follows pin out 1.0:
TWI: SDA and SCL pins close to AREF pin.
IOREF: allows a screen attached with the correct configuration to match the voltage provided by the board. This allows for screen compatibility with a 3.3V board such as Due and AVR boards that run on 5V.
There is one disconnected pin, reserved for future use.
