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Arduino Due

Category: Arduino
Manufacturer: Arduino
SKU: A000062
Status: Active
Release Year: 2012
Form Factor: Arduino Mega
Read Time: ~10 min read

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Arduino Due top view
Arduino Due bottom view
Arduino Due pinout
Arduino Due top view
Arduino Due bottom view
Arduino Due pinout

Overview

The Arduino Due was the first Arduino board based on a 32-bit ARM Cortex-M3 microcontroller, marking a significant leap in processing power and peripheral richness compared to the AVR-based boards that preceded it. At its heart is the Atmel AT91SAM3X8E running at 84 MHz, with 512 KB of flash and 96 KB of SRAM.

Released in 2012 and sharing the Mega physical form factor, the Due introduces features unavailable on 8-bit Arduino boards: two 12-bit DAC channels, a 12-bit ADC, two CAN bus controllers, and a native USB port capable of acting as a USB host or device (including HID). A second micro-USB port provides a traditional serial programming interface.

Critical notice: The Due operates at 3.3V logic. Its I/O pins are NOT 5V tolerant. Connecting 5V signals directly to any I/O pin will permanently damage the microcontroller. Most shields designed for the Uno or Mega (which use 5V logic) are not directly compatible without level shifting.

Quick Overview

Property Value
Microcontroller AT91SAM3X8E (32-bit ARM Cortex-M3)
Clock Speed 84 MHz
Operating Voltage 3.3V (NOT 5V tolerant on I/O)
Input Voltage (recommended) 7–12V
Digital I/O Pins 54 (12 with PWM)
Analog Input Pins 12 (12-bit ADC)
Analog Output (DAC) 2 × 12-bit (DAC0, DAC1)
Flash Memory 512 KB
SRAM 96 KB (64 KB + 32 KB dual banks)
Hardware UARTs 4 (Serial, Serial1, Serial2, Serial3)
CAN Controllers 2 (CAN0, CAN1)
USB Ports 2 × micro-USB (Programming + Native USB)
Dimensions 101.6 × 53.4 mm

Key Features

  • 32-bit ARM Cortex-M3 at 84 MHz — dramatically more processing power than AVR-based Arduino boards
  • 512 KB flash and 96 KB SRAM for large sketches and data buffers
  • Two 12-bit DAC channels providing true analog voltage output (not PWM)
  • 12-bit ADC on all 12 analog inputs for high-resolution sensor readings
  • Two CAN 2.0A/B controllers for automotive and industrial communication
  • Native USB port with HID support — act as USB keyboard, mouse, or MIDI device
  • Programming USB port provides a traditional serial upload path without interfering with the native USB application
  • Four hardware UART ports for multi-device serial communication
  • Two I2C buses and two SPI buses for versatile peripheral connectivity
  • Same physical form factor as the Arduino Mega 2560

Technical Specifications

Specification Value
Microcontroller Atmel AT91SAM3X8E
Architecture 32-bit ARM Cortex-M3
Clock Speed 84 MHz
Operating Voltage 3.3V
Recommended Input Voltage 7–12V
Digital I/O Pins 54
PWM Pins 12
Analog Input Pins 12 (12-bit ADC)
Analog Output (DAC) 2 × 12-bit (DAC0 on A0, DAC1 on A1)
DC Current per I/O Pin 130 mA (total), 3 mA per pin recommended
Flash Memory 512 KB
SRAM 96 KB (64 KB + 32 KB)
Hardware UARTs 4 (Serial, Serial1, Serial2, Serial3)
I2C 2
SPI 1 (ICSP header) + 1 (SPI header, pins 10–13)
CAN Controllers 2 (CAN0, CAN1 — CAN 2.0A/B)
USB 2 × micro-USB (Programming port + Native USB port)
Dimensions 101.6 × 53.4 mm

Pinout

Arduino Due top view

Digital I/O Pins

Pin Range Function
D0 (RX0) / D1 (TX0) Hardware Serial (Programming port)
D2–D13 General digital I/O; D3, D5, D6, D9, D10, D11, D13 PWM
D14 (TX3) / D15 (RX3) Hardware Serial3
D16 (TX2) / D17 (RX2) Hardware Serial2
D18 (TX1) / D19 (RX1) Hardware Serial1
D20 (SDA) / D21 (SCL) I2C bus 1
D70 (SDA1) / D71 (SCL1) I2C bus 2
D50 (MISO) / D51 (MOSI) / D52 (SCK) / D53 (SS) SPI bus

Analog Pins

Pin Function
A0 Analog input + DAC0 output
A1 Analog input + DAC1 output
A2–A11 Analog input (12-bit ADC)

Power Pins

Pin Description
VIN 7–12V input (same as barrel jack)
5V 5V output (from regulator) — for powering peripherals only, NOT for I/O logic
3.3V 3.3V regulated output
GND Ground
RESET Pull LOW to reset
IOREF 3.3V reference for shields

Power

The Arduino Due can be powered via:

  1. Programming micro-USB: 5V from host, sufficient for development use.
  2. Native micro-USB: 5V from host if the native port is connected.
  3. DC Barrel Jack: 7–12V DC (center positive). On-board regulator provides 3.3V.
  4. VIN Pin: Same range as the barrel jack.

The 5V pin on the Due outputs 5V but this voltage is only used for powering compatible peripherals — the MCU itself runs at 3.3V, and the I/O pins operate at 3.3V exclusively.

Microcontroller

The AT91SAM3X8E is a Cortex-M3 processor from Atmel (now Microchip). Key architectural details:

  • 32-bit RISC architecture with Thumb-2 instruction set
  • 84 MHz maximum clock with hardware multiply and divide
  • Two independent SRAM banks (64 KB + 32 KB) allowing simultaneous access from DMA and CPU
  • DMA controller (PDC/DMA) for zero-CPU-overhead peripheral transfers
  • Hardware floating-point is NOT present in Cortex-M3 (present in M4/M7); software FPU is used

Digital-to-Analog Converter

The Due includes two independent 12-bit DAC channels, which are a notable advantage over most Arduino boards that rely on PWM for analog-like output.

Channel Pin Resolution Notes
DAC0 A0 12-bit True analog voltage output, 0–3.3V range
DAC1 A1 12-bit True analog voltage output, 0–3.3V range

The DACs are ideal for audio signal generation, waveform synthesis, and precision analog control. The analogWrite() function on DAC pins outputs a true DC voltage, not a PWM signal.

// Output a sine wave approximation on DAC0 #include <math.h> void setup() { analogWriteResolution(12); // Set DAC to 12-bit (0–4095) } void loop() { for (int i = 0; i < 360; i++) { float radians = i * (PI / 180.0); int value = (int)(2047.5 + 2047.5 * sin(radians)); analogWrite(DAC0, value); delayMicroseconds(100); } }

HID Support

The Native USB port on the Due (connected directly to the AT91SAM3X8E) supports USB HID without any bridge chip. This means the Due can emulate USB keyboards, mice, and other HID devices.

The Keyboard and Mouse libraries work on the Due via the native USB port. Upload via the Programming port when using HID sketches, to avoid losing the upload connection.

#include <Keyboard.h> void setup() { Keyboard.begin(); delay(1000); Keyboard.print("Hello from Arduino Due!"); Keyboard.end(); } void loop() {}

Getting Started

What You Need

  • Arduino Due
  • Two micro-USB cables (one for Programming port, one optional for Native port)
  • Computer with Arduino IDE installed

Steps

  1. Connect the Programming port (the micro-USB closest to the power barrel jack) to your computer.
  2. Open the Arduino IDE.
  3. Install the SAM board package: Tools > Board > Boards Manager, search for "Arduino SAM Boards" and install.
  4. Select Tools > Board > Arduino SAM Boards > Arduino Due (Programming Port).
  5. Select the correct COM port under Tools > Port.
  6. Upload the Blink example.

Blink Example

// Blink the built-in LED on pin 13 void setup() { pinMode(13, OUTPUT); } void loop() { digitalWrite(13, HIGH); delay(1000); digitalWrite(13, LOW); delay(1000); }

Programming

The Due has two upload paths:

Port Use Case
Programming Port (micro-USB) Standard sketch upload; uses ATmega16U2-style reset; always available
Native USB Port (micro-USB) HID / USB device sketches; direct ARM USB; may disconnect during upload
  • Board package: Arduino SAM Boards (installed via Boards Manager)
  • Programmer: No external programmer needed for normal use; JTAG available for advanced debugging
  • Upload protocol: bossac (SAM-BA bootloader)
  • Auto-reset: Supported on the Programming port via 1200-baud touch

Shield Compatibility

WARNING: The Due operates at 3.3V logic. I/O pins are NOT 5V tolerant. Connecting 5V signals to the Due's I/O pins will permanently damage the microcontroller.

Shield Type Compatibility
5V Arduino Uno / Mega shields NOT compatible without level shifting — risk of permanent damage
3.3V shields Compatible
Shields using only I2C/SPI with 3.3V logic May work; verify signal levels first
Mega form factor shields (physical fit) Physically fit, but verify voltage levels

Before connecting any existing shield to the Due, verify that all signal lines operate at 3.3V. Level-shifting modules (e.g., TXB0108, 4-channel bidirectional level shifters) are required for mixing 5V and 3.3V devices.

CAN Bus

The Due includes two CAN 2.0A/B controllers (CAN0 and CAN1), making it suitable for automotive and industrial applications.

Controller Pins Standard
CAN0 CANRX0 (pin 69), CANTX0 (pin 68) CAN 2.0A/B
CAN1 CANRX1 (pin 67), CANTX1 (pin 66) CAN 2.0A/B

An external CAN transceiver (such as MCP2551) is required to connect the CAN controllers to a physical CAN bus. The due_can library and similar third-party libraries provide CAN communication support.

Package Contents

Item Quantity
Arduino Due board 1

Micro-USB cables are not included. Two are useful — one for the Programming port and one for the Native USB port.

Applications

  • High-speed signal processing requiring 32-bit arithmetic
  • Audio synthesis and playback using the dual 12-bit DAC
  • Automotive prototyping using the dual CAN bus controllers
  • USB HID device emulation (keyboard, mouse, MIDI)
  • Precision analog output applications (waveform generators, DAC-driven control systems)
  • Projects requiring large RAM buffers (image processing, communication stacks)
  • Industrial control systems requiring multiple serial buses

Where to Buy

Equivalent Boards

Board Key Difference
Arduino GIGA R1 WiFi Newer dual-core 32-bit ARM (M7+M4), built-in Wi-Fi/BT, Mega form factor
Arduino Mega 2560 8-bit AVR at 16 MHz, 5V logic, highly shield-compatible, no DAC or CAN
Arduino Zero Cortex-M0+ at 48 MHz, Uno form factor, 3.3V, single DAC, on-board debugger

Documentation

Notes

  • 3.3V I/O is the single most important fact about the Due. Every shield, sensor, and module connected to the I/O pins must be verified to operate at 3.3V. There is no internal protection against 5V signals.
  • The 5V pin on the headers outputs 5V (sourced from the USB or regulator) and can be used to power 5V peripherals, but must never be connected back to an I/O pin.
  • When using the Native USB port for HID sketches, always upload via the Programming port. Switching to native USB on the upload target will cause the IDE to lose connection.
  • The Due's SAM-BA bootloader can be triggered by double-pressing the ERASE button followed by the RESET button, which fully erases the flash — useful for recovery.

Community

Revision History

Version Date Notes
v1.0 2026-06 Initial entry