Arduino Compatible Due R3 SAM3X8E 32-Bit ARM Cortex-M3 Development Board is the flagship 32-bit ARM microcontroller board in the Mega 2560 form factor, powered by the Microchip/Atmel AT91SAM3X8E ARM Cortex-M3 processor running at 84 MHz. Furthermore, it integrates 512KB of Flash memory, 96KB of SRAM, dual true 12-bit Digital-to-Analog Converters (`DAC0` and `DAC1`), 12 channels of 12-bit 1 MSPS ADC, a hardware CAN 2.0B controller, and dual Micro-USB ports (Programming + Native USB OTG Host/Device). Consequently, it delivers over 5× the clock speed and 48× the RAM of an Arduino UNO for real-time audio synthesis, CNC/3D printer firmware, and automotive CAN-bus analysis.
Key Features:
- 84 MHz 32-Bit ARM Cortex-M3 Processor: Atmel SAM3X8E CPU with single-cycle 32-bit ALU, hardware divide, and peripheral DMA controller (PDC) for zero-CPU-overhead data transfers.
- Massive 512KB Flash & 96KB SRAM: Dual-bank 512KB Flash and 96KB contiguous SRAM (64KB + 32KB) easily handle large graphic framebuffers, FFT audio arrays, and RTOS kernels.
- True 12-Bit Dual DACs & 12-Bit ADCs: Includes 2 × true analog voltage output DAC pins (`DAC0, DAC1`) for stereo audio waveform generation plus 12 × 12-bit (4096-step) ADC inputs.
- Dual Micro-USB Ports (Programming + Native USB OTG): Dedicated ATmega16U2 Programming port alongside a Native High-Speed USB OTG port supporting `USBHost` (keyboards/mice) and `Keyboard/Mouse/MIDI` emulation.
- 54 Digital I/O, 4 UARTs & Hardware CAN Bus: Exposes `CANTX0/CANRX0`, 4 hardware serial ports, 2 I2C buses, SPI, and external interrupts on all 54 digital pins.
Technical Specifications:
- Microcontroller: Microchip / Atmel AT91SAM3X8E (LQFP-144, 32-Bit ARM Cortex-M3 @ 84 MHz)
- USB Programming Coprocessor: ATmega16U2
- Operating Logic Voltage: Strictly 3.3V DC (NOT 5V Tolerant!)
- Recommended Input Voltage (DC Jack / VIN): 7.0V to 12.0V DC (Onboard Switching Buck Regulator; 6V–16V Limits)
- Digital I/O Pins: 54 Pins (12 Dedicated 8-Bit/12-Bit PWM Outputs; All 54 Support `attachInterrupt()`)
- Analog Inputs (12-Bit ADC): 12 Channels (`A0–A11`, 0V–3.3V Input Range, 1000 ksps)
- Analog Outputs (12-Bit DAC): 2 True Analog Output Pins (`DAC0`, `DAC1`; 0.55V to 2.75V Output Swing)
- Memory: 512 KB Flash (2 × 256 KB Banks), 96 KB SRAM
- Total DC Output Current on All I/O Lines: 130 mA Max Combined (3 mA or 15 mA per Pin Depending on Port)
Mechanical Specifications:
- PCB Form Factor: Standard Arduino Mega R3 Extended Footprint (101.5mm × 53.3mm)
- Connectors: 2 × Micro-USB Type-B Receptacles (Programming & Native), 5.5mm × 2.1mm DC Barrel Jack, JTAG 10-Pin Header, SPI Header
- Onboard Buttons: Hardware `RESET` Tactile Button + Dedicated Flash `ERASE` Button
Dimensions:
- Length: 101.5 mm
- Width: 53.3 mm
- Height: 14.0 mm
- Weight: ≈ 36 g
Pinout and Wiring:
- Dual I2C Buses: `SDA (D20) / SCL (D21)` (with 1.5kΩ pull-ups to 3.3V) and `SDA1 / SCL1` near the AREF pin.
- 4 × Hardware UARTs: `RX0/TX0 (D0/D1)`, `RX1/TX1 (D19/D18)`, `RX2/TX2 (D17/D16)`, and `RX3/TX3 (D15/D14)`.
- Hardware CAN Bus: `CANRX0 (D68)` and `CANTX0 (D69)` located next to `DAC0` and `DAC1` (pair with an external 3.3V SN65HVD230 CAN transceiver).
- SPI Bus: Exposed exclusively on the central 6-pin `SPI` header (with hardware chip-select support on pins `D4, D10, D52`).
- Engineering Precaution: Unlike the 5V Arduino Mega 2560, every I/O pin on the Arduino Due operates strictly at **3.3V max** and is NOT 5V-tolerant; applying 5V logic to any Due digital or analog pin will immediately destroy the SAM3X8E processor.
Datasheet Reference:
Commonly Used in:
- Dual-CAN-Bus Automotive OBD-II / J1939 SavvyCAN Sniffers & Gateways
- High-Speed 32-Bit RepRap/Marlin/RADDS 3D Printers and CNC Motion Controllers
- Real-Time Digital Audio Synthesizers, Guitar DSP Pedals, and Oscilloscopes
Applications:
- Dual-Channel Audio & Waveform Synthesis: Streams DMA-driven 44.1 kHz 12-bit audio or arbitrary sine/triangle waves out of `DAC0` and `DAC1`.
- Automotive CAN-Bus Reverse Engineering: Pairs with a 3.3V CAN shield and open-source `DueCAN` / `GVRET` firmware for SavvyCAN vehicle diagnostics.
- High-Speed Multi-Axis Stepper Control: Generates jitter-free 100 kHz+ step pulses across 54 digital I/O pins.
Equivalent Models:
- Arduino Mega 2560 R3 (ATmega2560): 16MHz 8-bit AVR board in the same 54-pin footprint when rugged 5V I/O logic and 4KB internal EEPROM are required.
- STM32F103C8T6 Blue Pill: Compact 72MHz ARM Cortex-M3 board with 64KB Flash and 37 GPIOs for breadboard applications.
- Raspberry Pi Pico (RP2040): 133MHz dual-core Cortex-M0+ board in a 40-pin DIP form factor.
Package Includes:
- 1 × Arduino Compatible Due R3 SAM3X8E 32-Bit ARM Cortex-M3 Development Board
