zephyr-cc1352-development.rst

Wireless MCU Zephyr Development

BeaglePlay includes a Texas Instruments CC1352P7 wireless microcontroller (MCU) that can be programmed using the Linux Foundation Zephyr RTOS.

Developing directly in Zephyr will not be ultimately required for end-users who won't touch the firmware running on the CC1352 on BeaglePlay™ and will instead use the provided wireless functionality. However, it is important for early adopters as well as people looking to extend the functionality of the open source design. If you are one of those people, this is a good place to get started.

Further, BeaglePlay is a reasonable development platform for creating Zephyr-based applications for :ref:`beagleconnect_freedom_home`. The same Zephyr development environment setup here is also described for targeting applications on that board.

Install the latest software image for BeaglePlay

Note

These instructions should be generic for BeaglePlay and other boards and only the specifics of which image was used to test these instructions need be included here moving forward and the detailed instructions can be referenced elsewhere.

You may want to download and install the latest Debian Linux operating system image for BeaglePlay.

Note

These instructions were validated with the BeagleBoard.org Debian image BeaglePlay Debian 11.6 Flasher 2023-03-10.

1. Load this image to a microSD card using a tool like Etcher.
2. Insert the microSD card into BeaglePlay.
3. Power BeaglePlay via the USB-C connector.
4. Wait for the LEDs to start blinking, then turn off.
5. Remove power from BeaglePlay.
6. IMPORTANT Remove microSD card from BeaglePlay.
7. Apply power to BeaglePlay.

Note

This will flash the CC1352 as well as the eMMC flash on BeaglePlay.

Log into BeaglePlay

Please either plug in a keyboard, monitor and mouse or ssh into the board. We can point somewhere else for instructions on this. You can also point your web browser to the board to log into the Visual Studio Code IDE environment.

Flash existing IEEE 802.15.4 radio bridge (WPANUSB) firmware

If you've recieved a board fresh from the factory, this is already done and not necessary, unless you want to restore the contents back to the factory condition.

Background

This WPANUSB application was originally developed for radio devices with a USB interface. The CC1352P7 does not have a USB device, so the application was modified to communicate over a UART serial interface.

For the :ref:`beagleconnect_freedom_home`, a USB-to-UART bridge device was used and the USB endpoints were made compatible with the WPANUSB linux driver which we augmented to support this board. To utilize the existing WPANUSB Zephyr application and this Linxu driver, we chose to encode our UART traffic with HDLC. This has the advantage of enabing a serial console interface to the Zephyr shell while WPANUSB-specific traffic is directed to other USB endpoints.

For BeaglePlay, the USB-to-UART bridge is not used, but we largely kept the same WPANUSB application, including the HDLC encoding.

Note

Now you know why this WPAN bridge application is called WPANUSB, even though USB isn't used!

Steps

1. Ensure the bcfserial driver isn't blocking the serial port.

   echo "    fdtoverlays /overlays/k3-am625-beagleplay-bcfserial-no-firmware.dtbo" | sudo tee -a /boot/firmware/extlinux/extlinux.conf
   sudo shutdown -r now

   Note

   The default password is temppwd.

2. Download and flash the WPANUSB Zephyr application firmware onto the CC1352P7 on BeaglePlay from the releases on git.beagleboard.org or distros on www.beagleboard.org/distros.

   cd
   wget https://files.beagle.cc/file/beagleboard-public-2021/images/download
   unzip download
   build/play/cc2538-bsl.py build/play/wpanusb

3. Ensure the bcfserial driver is set to load.

   sudo sed -e '/bcfserial-no-firmware/ s/^#*/#/' -i /boot/firmware/extlinux/extlinux.conf
   sudo shutdown -r now

4. Verify the the 6LoWPAN network is up.

Note

You may find Linux-WPAN.org useful.

Setup Zephyr development on BeaglePlay

1. Download and setup Zephyr for BeaglePlay

   cd
   sudo apt update
   sudo apt install --no-install-recommends -y \
       gperf \
       ccache dfu-util \
       libsdl2-dev \
       libxml2-dev libxslt1-dev libssl-dev libjpeg62-turbo-dev libmagic1 \
       libtool-bin autoconf automake libusb-1.0-0-dev \
       python3-tk python3-virtualenv
   wget https://github.com/zephyrproject-rtos/sdk-ng/releases/download/v0.15.1/zephyr-sdk-0.15.1_linux-aarch64_minimal.tar.gz
   tar xf zephyr-sdk-0.15.1_linux-aarch64_minimal.tar.gz
   rm zephyr-sdk-0.15.1_linux-aarch64_minimal.tar.gz
   ./zephyr-sdk-0.15.1/setup.sh -t arm-zephyr-eabi -c
   west init -m https://git.beagleboard.org/beagleconnect/zephyr/zephyr --mr sdk zephyr-beagle-cc1352-sdk
   cd $HOME/zephyr-beagle-cc1352-sdk
   python3 -m virtualenv zephyr-beagle-cc1352-env
   echo "export ZEPHYR_TOOLCHAIN_VARIANT=zephyr" >> $HOME/zephyr-beagle-cc1352-sdk/zephyr-beagle-cc1352-env/bin/activate
   echo "export ZEPHYR_SDK_INSTALL_DIR=$HOME/zephyr-sdk-0.15.1" >> $HOME/zephyr-beagle-cc1352-sdk/zephyr-beagle-cc1352-env/bin/activate
   echo "export ZEPHYR_BASE=$HOME/zephyr-beagle-cc1352-sdk/zephyr" >> $HOME/zephyr-beagle-cc1352-sdk/zephyr-beagle-cc1352-env/bin/activate
   echo 'export PATH=$HOME/zephyr-beagle-cc1352-sdk/zephyr/scripts:$PATH' >> $HOME/zephyr-beagle-cc1352-sdk/zephyr-beagle-cc1352-env/bin/activate
   echo "export BOARD=beagleplay" >> $HOME/zephyr-beagle-cc1352-sdk/zephyr-beagle-cc1352-env/bin/activate
   source $HOME/zephyr-beagle-cc1352-sdk/zephyr-beagle-cc1352-env/bin/activate
   west update
   west zephyr-export
   pip3 install -r zephyr/scripts/requirements-base.txt

2. Activate the Zephyr build environment

   If you exit and come back, you'll need to reactivate your Zephyr build environment.

   source $HOME/zephyr-beagle-cc1352-sdk/zephyr-beagle-cc1352-env/bin/activate

3. Verify Zephyr setup for BeaglePlay

   (zephyr-beagle-cc1352-env) debian@BeaglePlay:~$ cmake --version
   cmake version 3.22.1
   
   CMake suite maintained and supported by Kitware (kitware.com/cmake).
   (zephyr-beagle-cc1352-env) debian@BeaglePlay:~$ python3 --version
   Python 3.9.2
   (zephyr-beagle-cc1352-env) debian@BeaglePlay:~$ dtc --version
   Version: DTC 1.6.0
   (zephyr-beagle-cc1352-env) debian@BeaglePlay:~$ west --version
   West version: v0.14.0
   (zephyr-beagle-cc1352-env) debian@BeaglePlay:~$ ./zephyr-sdk-0.15.1/arm-zephyr-eabi/bin/arm-zephyr-eabi-gcc --version
   arm-zephyr-eabi-gcc (Zephyr SDK 0.15.1) 12.1.0
   Copyright (C) 2022 Free Software Foundation, Inc.
   This is free software; see the source for copying conditions.  There is NO
   warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Build applications for BeaglePlay CC1352

Now you can build various Zephyr applications

1. Build and flash Blinky example

   cd $HOME/zephyr-beagle-cc1352-sdk/zephyr
   west build -d build/play_blinky samples/basic/blinky
   west flash -d build/play_blinky

2. Try out Micropython

   cd
   git clone -b beagleplay-cc1352 https://git.beagleboard.org/beagleplay/micropython
   cd micropython
   west build -d play ports/zephyr
   west flash -d play
   tio /dev/ttyS4

Build applications for BeagleConnect Freedom

1. Build and flash Blinky example

   cd $HOME/zephyr-beagle-cc1352-sdk/zephyr
   west build -d build/freedom_blinky -b beagleconnect_freedom samples/basic/blinky
   west flash -d build/freedom_blinky

2. Try out Micropython

   cd
   git clone -b beagleplay-cc1352 https://git.beagleboard.org/beagleplay/micropython
   cd micropython
   west build -d freedom -b beagleconnect_freedom ports/zephyr
   west flash -d freedom
   tio /dev/ttyACM0

Important

Nothing below here is tested

1. TODO

   west build -d build/sensortest zephyr/samples/boards/beagle_bcf/sensortest -- -DOVERLAY_CONFIG=overlay-subghz.conf

2. TODO

   west build -d build/wpanusb modules/lib/wpanusb_bc -- -DOVERLAY_CONFIG=overlay-subghz.conf

3. TODO

   west build -d build/bcfserial modules/lib/wpanusb_bc -- -DOVERLAY_CONFIG=overlay-bcfserial.conf -DDTC_OVERLAY_FILE=bcfserial.overlay

4. TODO

   west build -d build/greybus modules/lib/greybus/samples/subsys/greybus/net -- -DOVERLAY_CONFIG=overlay-802154-subg.conf

Flash applications to BeagleConnect Freedom

And then you can flash the BeagleConnect Freedom boards over USB

1. Make sure you are in Zephyr directory

   cd $HOME/bcf-zephyr

2. Flash Blinky

   cc2538-bsl.py build/blinky

Debug applications over the serial terminal