| .. _arduino_due: |
| |
| Arduino Due |
| ########### |
| |
| Overview |
| ******** |
| |
| The arduino_due board configuration is used by Zephyr applications |
| that run on the Arduino Due board. It provides support for the Atmel |
| SAM3X8E ARM Cortex-M3 CPU and the following devices: |
| |
| * Nested Vectored Interrupt Controller (NVIC) |
| |
| * System Tick System Clock (SYSTICK) |
| |
| * Serial Port over USB (ATMEL_SAM3) |
| |
| More information about the board can be found at the `Arduino Due website`_. |
| The `Atmel SAM3X8E Datasheet`_ has the information and the datasheet about |
| the processor. |
| |
| .. note:: |
| This configuration is not supported by Arduino. |
| |
| .. image:: img/arduino_due.jpg |
| :align: center |
| :alt: Arduino Due |
| |
| Hardware |
| ******** |
| Supported Features |
| ================== |
| |
| The arduino_due board configuration supports the following hardware features: |
| |
| +-----------+------------+----------------------+ |
| | Interface | Controller | Driver/Component | |
| +===========+============+======================+ |
| | NVIC | on-chip | nested vectored | |
| | | | interrupt controller | |
| +-----------+------------+----------------------+ |
| | SYSTICK | on-chip | system clock | |
| +-----------+------------+----------------------+ |
| | UART | on-chip | serial port | |
| +-----------+------------+----------------------+ |
| | GPIO | on-chip | gpio | |
| +-----------+------------+----------------------+ |
| | I2C | on-chip | i2c | |
| +-----------+------------+----------------------+ |
| | Watchdog | on-chip | watchdog | |
| +-----------+------------+----------------------+ |
| |
| Other hardware features are not currently supported by the Zephyr kernel. |
| See `Arduino Due website`_ and `Atmel SAM3X8E Datasheet`_ for a complete |
| list of Arduino Due board hardware features. |
| |
| The default configuration can be found in the Kconfig |
| :zephyr_file:`boards/arduino/due/arduino_due_defconfig`. |
| |
| .. note:: |
| For I2C, pull-up resistors are required for using SCL1 and SDA1 (near IO13). |
| |
| Interrupt Controller |
| ==================== |
| |
| There are 15 fixed exceptions including exceptions 12 (debug monitor) and 15 |
| (SYSTICK) that behave more as interrupts than exceptions. In addition, there can |
| be a variable number of IRQs. Exceptions 7-10 and 13 are reserved. They don't |
| need handlers. |
| |
| A Cortex-M3/4-based board uses vectored exceptions. This means each exception |
| calls a handler directly from the vector table. |
| |
| Handlers are provided for exceptions 1-6, 11-12, and 14-15. The table here |
| identifies the handlers used for each exception. |
| |
| +------+------------+----------------+-----------------------+ |
| | Exc# | Name | Remarks | Used by Zephyr Kernel | |
| +======+============+================+=======================+ |
| | 1 | Reset | | system initialization | |
| +------+------------+----------------+-----------------------+ |
| | 2 | NMI | | system fatal error | |
| +------+------------+----------------+-----------------------+ |
| | 3 | Hard fault | | system fatal error | |
| +------+------------+----------------+-----------------------+ |
| | 4 | MemManage | MPU fault | system fatal error | |
| +------+------------+----------------+-----------------------+ |
| | 5 | Bus | | system fatal error | |
| +------+------------+----------------+-----------------------+ |
| | 6 | Usage | undefined | system fatal error | |
| | | fault | instruction, | | |
| | | | or switch | | |
| | | | attempt to ARM | | |
| | | | mode | | |
| +------+------------+----------------+-----------------------+ |
| | 11 | SVC | | system calls, kernel | |
| | | | | run-time exceptions, | |
| | | | | and IRQ offloading | |
| +------+------------+----------------+-----------------------+ |
| | 12 | Debug | | system fatal error | |
| | | monitor | | | |
| +------+------------+----------------+-----------------------+ |
| | 14 | PendSV | | context switch | |
| +------+------------+----------------+-----------------------+ |
| | 15 | SYSTICK | | system clock | |
| +------+------------+----------------+-----------------------+ |
| |
| .. note:: |
| After a reset, all exceptions have a priority of 0. Interrupts cannot run |
| at priority 0 for the interrupt locking mechanism and exception handling |
| to function properly. |
| |
| System Clock |
| ============ |
| |
| Arduino Due has two external oscillators/resonators. The slow clock is |
| 32.768 kHz, and the main clock is 12 MHz. The processor can set up PLL to drive |
| the master clock, which can be set as high as 84 MHz. |
| |
| Serial Port |
| =========== |
| |
| The Atmel SAM3X8E processor has a single UART that is used by the SAM-BA |
| bootloader. This UART has only two wires for RX/TX and does not have flow |
| control (CTS/RTS) or FIFO. The RX/TX pins are connected to the ATmega16U2, |
| which provides USB-to-TTL serial function. The Zephyr console output, by |
| default, is utilizing this controller. |
| |
| |
| Programming and Debugging |
| ************************* |
| |
| Flashing |
| ======== |
| |
| BOSSA Tool |
| ---------- |
| |
| Flashing the Zephyr kernel onto Arduino Due requires the `bossa tool`_. |
| |
| There are GUI and command line versions of the bossa tool. The following |
| section provides the steps to build the command line version. Please |
| refer to the bossa tool's README file on how to build the GUI version. |
| |
| To build the bossa tool, follow these steps: |
| |
| #. Checkout the bossa tool's code from the repository. |
| |
| .. code-block:: console |
| |
| $ git clone https://github.com/shumatech/BOSSA.git |
| $ cd BOSSA |
| |
| #. Checkout the arduino branch. The code on the master branch does not |
| work with Arduino Due. |
| |
| .. code-block:: console |
| |
| $ git checkout arduino |
| |
| #. Build the command line version of the bossa tool. |
| |
| .. code-block:: console |
| |
| $ make bin/bossac |
| |
| #. The resulting binary is available at :file:`bin/bossac`. |
| |
| |
| Flashing an Application to Arduino Due |
| -------------------------------------- |
| |
| Applications for the ``arduino_due`` board configuration can be built |
| and flashed in the usual way (see :ref:`build_an_application` and |
| :ref:`application_run` for more details). |
| |
| Here is an example for the :zephyr:code-sample:`hello_world` application. After |
| building the application, press the Reset button before running the |
| flash command, so the board will boot into the SAM-BA bootloader and |
| be prepared to receive the new program. |
| |
| .. zephyr-app-commands:: |
| :zephyr-app: samples/hello_world |
| :board: arduino_due |
| :goals: build flash |
| |
| After flashing the application, run your favorite terminal program to |
| listen for output. For example, under Linux, the terminal should be |
| :code:`/dev/ttyACM0`. For example: |
| |
| .. code-block:: console |
| |
| $ sudo minicom -D /dev/ttyACM0 -o |
| |
| The -o option tells minicom not to send the modem initialization |
| string. |
| |
| Now press the Reset button and you should see "Hello World! arduino_due" in your terminal. |
| |
| .. note:: |
| Make sure your terminal program is closed before flashing the binary image, |
| or it will interfere with the flashing process. |
| |
| References |
| ********** |
| |
| .. target-notes:: |
| |
| .. _Arduino Due website: https://www.arduino.cc/en/Main/ArduinoBoardDue |
| |
| .. _Atmel SAM3X8E Datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-11057-32-bit-Cortex-M3-Microcontroller-SAM3X-SAM3A_Datasheet.pdf |
| |
| .. _bossa tool: https://github.com/shumatech/BOSSA |
| |
| .. _bossa arduino branch: https://github.com/shumatech/BOSSA/tree/arduino |
