215 lines
7.4 KiB
ReStructuredText
215 lines
7.4 KiB
ReStructuredText
.. _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.png
|
|
:width: 500px
|
|
: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/arm/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 | | context switch and |
|
|
| | | | software interrupts |
|
|
+------+------------+----------------+-----------------------+
|
|
| 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 :ref:`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!" 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
|
|
**********
|
|
|
|
.. _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
|