Repositories

zephyr: A public fork of Zephyr is maintained for contributing patches to the Zephyr Project: the usb3 branch contains modifications that are required for the tinyCLUNX33 to work with USB3, and are in the process of being upstreamed. For everything else, the upstream Zephyr repository is used unchanged.
tinyvision_zephyr_sdk The tinyVision Zephyr SDK contains additional drivers implemented by tinyVision.ai that are compatible with upstream Zephyr, which will also be upstreamed in the long term. This allows shipping features long before, without forking the entire Zephyr project.
tinyclunx33_zephyr_example: The tinyCLUNX33 Zephyr Example repository is a starting point for new applications, and makes use of the tinyVision Zephyr SDK.

The dependencies are managed the west.yml file. The example repository contains a west.yml that has all the dependencies correctly setup already, and more can be added for integrating 3rd-party code, or splitting a larger codebase in modules.

Building the firmware

This guide uses the tinyclunx33_zephyr_example sample application named app_imx219.

There are several targets for building the firmware, depending on what platform you wish to build on:

Shield: tinyclunx33_devkit_rev1, tinyclunx33_devkit_rev2, custom
Board: tinyclunx33@rev1, tinyclunx33@rev2
SoC: rtl008, rtl009, rtl010, custom

Assuming a Board Rev2, a Devkit Rev2, and SoC RTL010 being used:

Follow the general Zephyr to setup the build environment for your platform: https://docs.zephyrproject.org/latest/develop/getting_started/index.html
Reset the workspace directory you created from Zephyr's Getting Started Guide
cd ~/zephyrproject

rm -rf .west
Download the tinyCLUNX33 Zephyr example repository. This will also download the tinyVision Zephyr SDK as a dependency:
west init -m https://github.com/tinyvision-ai-inc/tinyclunx33_zephyr_example

west update
Build a sample application from this example repository, for instance app_imx219.
cd tinyclunx33_zephyr_example/app_imx219

west build --board tinyclunx33@rev2/rtl010 --shield tinyclunx33_devkit_rev2
Then, program the firmware into the devkit, with the DEBUG interface connected.
west flash

See also SoM Flash for other flash programming options.

You should now be able to see messages through the UART interface, a new USB Video Class (UVC) interface showing-up on your operating system, and if an IMX219 image sensor is connected, a video stream coming out of it.

Including the SDK into your existing project

In case your application was started without using the SDK, you may be interested in adding it as a dependency in west.yml, by adding the following snippet at the bottom of the file:

...
 
    - name: tinyclunx33_sdk
      url: https://github.com/tinyvision-ai-inc/zephyr_internal

Troubleshooting

The first sign of life from the Zephyr RTOS comes the UART interface, available by plugging the DEBUG USB cable.

In order to get early boot logs, you can hit the SW2 button which will reset the board but keep the serial console attached.

Depending on firmware configuration (see chosen { zephyr,shell-uart = ...; } property of build/zephyr/zephyr.dts), the Zephyr shell will be available over that same UART interface. For the Shell example, this goes through the DATA USB port, /dev/ttyACM0.

These debug commands permit to review the internal state of the USB peripheral, using subcommands of dwc3.

Interactive help is given by entering the help dwc3 comand.

If nothing comes through the UART, see the FPGA troubleshooting section.