de13103f0b
Add .. zephyr:board-supported-runners:: to the Programming and Debugging section of the documentation for each board that has one such section, as this is the most natural place to put it. Signed-off-by: Benjamin Cabé <benjamin@zephyrproject.org>
171 lines
4.7 KiB
ReStructuredText
171 lines
4.7 KiB
ReStructuredText
.. zephyr:board:: adafruit_itsybitsy_m4_express
|
|
|
|
Overview
|
|
********
|
|
|
|
The Adafruit ItsyBitsy M4 express is a small (36 mm x 18 mm) ARM development
|
|
board with an onboard RGB LED, USB port, 2 MiB of SPI flash, and range of I/O
|
|
broken out onto 23 GPIO pins.
|
|
|
|
Hardware
|
|
********
|
|
|
|
- ATSAMD51G19A ARM Cortex-M4 processor at 120 MHz
|
|
- 512 KiB of flash memory and 192 KiB of RAM
|
|
- 2 MiB of SPI flash
|
|
- Internal trimmed 8 MHz oscillator
|
|
- A user LED
|
|
- An RGB DotStar LED
|
|
- Native USB port
|
|
- One reset button
|
|
|
|
Supported Features
|
|
==================
|
|
|
|
.. zephyr:board-supported-hw::
|
|
|
|
Zephyr can use the default Cortex-M SYSTICK timer or the SAM0 specific RTC.
|
|
To use the RTC, set :code:`CONFIG_CORTEX_M_SYSTICK=n` and set
|
|
:code:`CONFIG_SYS_CLOCK_TICKS_PER_SEC` to no more than 32 kHZ divided by 7,
|
|
i.e. no more than 4500.
|
|
|
|
Connections and IOs
|
|
===================
|
|
|
|
The `Adafruit Learning System`_ has detailed information about
|
|
the board including `pinouts`_ and the `schematic`_.
|
|
|
|
System Clock
|
|
============
|
|
|
|
The SAMD51 MCU is configured to use the 32 kHz internal oscillator
|
|
with the on-chip PLL generating the 120 MHz system clock.
|
|
|
|
Serial Port
|
|
===========
|
|
|
|
The SAMD51 MCU has 6 SERCOM based USARTs. On the ItsyBitsy, SERCOM3 is
|
|
the Zephyr console and is available on pins 0 (RX) and 1 (TX).
|
|
|
|
SPI Port
|
|
========
|
|
|
|
The SAMD51 MCU has 6 SERCOM based SPIs. On the ItsyBitsy, SERCOM1 can be put
|
|
into SPI mode and used to connect to devices over the SCK (SCLK), MO (MOSI), and
|
|
MI (MISO) pins.
|
|
|
|
PWM
|
|
===
|
|
|
|
The SAMD51 has three PWM generators with up to six channels each. :code:`TCC_0`
|
|
has a resolution of 24 bits and all other generators are 16 bit. :code:`TCC_1`
|
|
pin 2 is mapped to PA18 (D7) and pin 3 is mapped to PA19 (D9).
|
|
|
|
USB Device Port
|
|
===============
|
|
|
|
The SAMD51 MCU has a USB device port that can be used to communicate
|
|
with a host PC. See the :zephyr:code-sample-category:`usb` sample applications for
|
|
more, such as the :zephyr:code-sample:`usb-cdc-acm` sample which sets up a virtual
|
|
serial port that echos characters back to the host PC.
|
|
|
|
Programming and Debugging
|
|
*************************
|
|
|
|
.. zephyr:board-supported-runners::
|
|
|
|
The ItsyBitsy ships with a the BOSSA compatible UF2 bootloader. The
|
|
bootloader can be entered by quickly tapping the reset button twice.
|
|
|
|
Additionally, if :code:`CONFIG_USB_CDC_ACM` is enabled then the bootloader
|
|
will be entered automatically when you run :code:`west flash`.
|
|
|
|
Flashing
|
|
========
|
|
|
|
#. Build the Zephyr kernel and the :zephyr:code-sample:`hello_world` sample application:
|
|
|
|
.. zephyr-app-commands::
|
|
:zephyr-app: samples/hello_world
|
|
:board: adafruit_itsybitsy_m4_express
|
|
:goals: build
|
|
:compact:
|
|
|
|
#. Connect the ItsyBitsy to your host computer using USB
|
|
|
|
#. Connect a 3.3 V USB to serial adapter to the board and to the
|
|
host. See the `Serial Port`_ section above for the board's pin
|
|
connections.
|
|
|
|
#. Run your favorite terminal program to listen for output. Under Linux the
|
|
terminal should be :code:`/dev/ttyUSB0`. For example:
|
|
|
|
.. code-block:: console
|
|
|
|
$ minicom -D /dev/ttyUSB0 -o
|
|
|
|
The -o option tells minicom not to send the modem initialization
|
|
string. Connection should be configured as follows:
|
|
|
|
- Speed: 115200
|
|
- Data: 8 bits
|
|
- Parity: None
|
|
- Stop bits: 1
|
|
|
|
#. Tap the reset button twice quickly to enter bootloader mode
|
|
|
|
#. Flash the image:
|
|
|
|
.. zephyr-app-commands::
|
|
:zephyr-app: samples/hello_world
|
|
:board: adafruit_itsybitsy_m4_express
|
|
:goals: flash
|
|
:compact:
|
|
|
|
You should see "Hello World! adafruit_itsybitsy_m4_express" in your terminal.
|
|
|
|
Debugging
|
|
=========
|
|
|
|
In addition to the built-in bootloader, the ItsyBitsy can be flashed and
|
|
debugged using a SWD probe such as the Segger J-Link.
|
|
|
|
#. Connect the board to the probe by connecting the :code:`SWCLK`,
|
|
:code:`SWDIO`, :code:`RESET`, :code:`GND`, and :code:`3V3` pins on the
|
|
ItsyBitsy to the :code:`SWCLK`, :code:`SWDIO`, :code:`RESET`, :code:`GND`,
|
|
and :code:`VTref` pins on the `J-Link`_.
|
|
|
|
#. Flash the image:
|
|
|
|
.. zephyr-app-commands::
|
|
:zephyr-app: samples/hello_world
|
|
:board: adafruit_itsybitsy_m4_express
|
|
:goals: flash
|
|
:flash-args: -r openocd
|
|
:compact:
|
|
|
|
#. Start debugging:
|
|
|
|
.. zephyr-app-commands::
|
|
:zephyr-app: samples/hello_world
|
|
:board: adafruit_itsybitsy_m4_express
|
|
:goals: debug
|
|
:compact:
|
|
|
|
References
|
|
**********
|
|
|
|
.. target-notes::
|
|
|
|
.. _Adafruit Learning System:
|
|
https://learn.adafruit.com/introducing-adafruit-itsybitsy-m4
|
|
|
|
.. _pinouts:
|
|
https://learn.adafruit.com/introducing-adafruit-itsybitsy-m4/pinouts
|
|
|
|
.. _schematic:
|
|
https://learn.adafruit.com/introducing-adafruit-itsybitsy-m4/downloads
|
|
|
|
.. _J-Link:
|
|
https://www.segger.com/products/debug-probes/j-link/technology/interface-description/
|