177 lines
5.5 KiB
ReStructuredText
177 lines
5.5 KiB
ReStructuredText
.. _seeeduino_xiao:
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Seeeduino XIAO
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##############
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Overview
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********
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The Seeeduino XIAO is a tiny (20 mm x 17.5 mm) ARM development
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board with onboard LEDs, USB port, and range of I/O broken out
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onto 14 pins.
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.. image:: img/seeeduino_xiao.jpg
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:align: center
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:alt: Seeeduino XIAO
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Hardware
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********
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- ATSAMD21G18A ARM Cortex-M0+ processor at 48 MHz
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- 256 KiB flash memory and 32 KiB of RAM
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- Three user LEDs
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- Native USB port
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Supported Features
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==================
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The seeeduino_xiao board configuration supports the following hardware
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features:
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+-----------+------------+------------------------------------------+
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| Interface | Controller | Driver/Component |
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+===========+============+==========================================+
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| DMA | on-chip | Direct memory access |
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+-----------+------------+------------------------------------------+
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| DAC | on-chip | Digital to analogue converter |
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+-----------+------------+------------------------------------------+
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| Flash | on-chip | Can be used with LittleFS to store files |
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+-----------+------------+------------------------------------------+
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| GPIO | on-chip | I/O ports |
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+-----------+------------+------------------------------------------+
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| HWINFO | on-chip | Hardware info |
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+-----------+------------+------------------------------------------+
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| I2C | on-chip | Inter-Integrated Circuit |
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+-----------+------------+------------------------------------------+
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| NVIC | on-chip | nested vector interrupt controller |
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+-----------+------------+------------------------------------------+
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| SPI | on-chip | Serial Peripheral Interface ports |
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+-----------+------------+------------------------------------------+
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| SYSTICK | on-chip | systick |
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+-----------+------------+------------------------------------------+
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| USART | on-chip | Serial ports |
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+-----------+------------+------------------------------------------+
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| USB | on-chip | USB device |
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+-----------+------------+------------------------------------------+
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| WDT | on-chip | Watchdog |
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+-----------+------------+------------------------------------------+
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Other hardware features are not currently supported by Zephyr.
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The default configuration can be found in the Kconfig file
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:zephyr_file:`boards/seeed/seeeduino_xiao/seeeduino_xiao_defconfig`.
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Connections and IOs
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===================
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The `Seeeduino XIAO wiki`_ has detailed information about
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the board including `pinouts`_ and the `schematic`_.
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System Clock
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============
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The SAMD21 MCU is configured to use the 32 kHz external crystal
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with the on-chip PLL generating the 48 MHz system clock. The internal
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APB and GCLK unit are set up in the same way as the upstream Arduino
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libraries.
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SPI Port
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========
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The SAMD21 MCU has 6 SERCOM based SPIs. On the XIAO, SERCOM0 can be put
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into SPI mode and used to connect to devices over pin 9 (MISO), pin 10
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(MOSI), and pin 8 (SCK).
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I2C Port
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========
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The SAMD21 MCU has 6 SERCOM based USARTs. On the XIAO, SERCOM2 is available on
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pin 4 (SDA) and pin 5 (SCL).
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Serial Port
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===========
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The SAMD21 MCU has 6 SERCOM based USARTs. On the XIAO, SERCOM4 is
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the Zephyr console and is available on pins 7 (RX) and 6 (TX).
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USB Device Port
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===============
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The SAMD21 MCU has a USB device port that can be used to communicate
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with a host PC. See the :ref:`usb-samples` sample applications for
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more, such as the :zephyr:code-sample:`usb-cdc-acm` sample which sets up a virtual
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serial port that echos characters back to the host PC.
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DAC
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===
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The SAMD21 MCU has a single channel DAC with 10 bits of resolution. On
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the XIAO, the DAC is available on pin 0.
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Programming and Debugging
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*************************
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The XIAO ships the BOSSA compatible UF2 bootloader. The bootloader can be
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entered by shorting the RST and GND pads twice.
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Additionally, if :code:`CONFIG_USB_CDC_ACM` is enabled then the bootloader
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will be entered automatically when you run :code:`west flash`.
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Flashing
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========
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#. Build the Zephyr kernel and the :ref:`hello_world` sample application:
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.. zephyr-app-commands::
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:zephyr-app: samples/hello_world
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:board: seeeduino_xiao
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:goals: build
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:compact:
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#. Connect the XIAO to your host computer using USB
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#. Connect a 3.3 V USB to serial adapter to the board and to the
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host. See the `Serial Port`_ section above for the board's pin
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connections.
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#. Run your favorite terminal program to listen for output. Under Linux the
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terminal should be :code:`/dev/ttyUSB0`. For example:
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.. code-block:: console
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$ minicom -D /dev/ttyUSB0 -o
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The -o option tells minicom not to send the modem initialization
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string. Connection should be configured as follows:
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- Speed: 115200
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- Data: 8 bits
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- Parity: None
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- Stop bits: 1
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#. Short the RST and GND pads twice quickly to enter bootloader mode
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#. Flash the image:
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.. zephyr-app-commands::
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:zephyr-app: samples/hello_world
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:board: seeeduino_xiao
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:goals: flash
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:compact:
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You should see "Hello World! seeeduino_xiao" in your terminal.
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References
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**********
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.. target-notes::
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.. _Seeeduino XIAO wiki:
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https://wiki.seeedstudio.com/Seeeduino-XIAO/
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.. _pinouts:
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https://wiki.seeedstudio.com/Seeeduino-XIAO/#hardware-overview
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.. _schematic:
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https://wiki.seeedstudio.com/Seeeduino-XIAO/#resourses
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