| .. _target-raspberry-pi-pico: |
| |
| ----------------- |
| Raspberry Pi Pico |
| ----------------- |
| .. warning:: |
| This target is in an early state and is under active development. Usability |
| is not very polished, and many features/configuration options that work in |
| upstream Pi Pico CMake build have not yet been ported to the GN build. |
| |
| ----- |
| Setup |
| ----- |
| To use this target, Pigweed must be set up to build against the Raspberry Pi |
| Pico SDK. This can be downloaded via ``pw package``, and then the build must be |
| manually configured to point to the location of the downloaded SDK. |
| |
| .. code:: sh |
| |
| pw package install pico_sdk |
| |
| gn args out |
| # Add these lines, replacing ${PW_ROOT} with the path to the location that |
| # Pigweed is checked out at. |
| PICO_SRC_DIR = "${PW_ROOT}/.environment/packages/pico_sdk" |
| |
| ----- |
| Usage |
| ----- |
| The Pi Pico is currently configured to output logs and test results over UART |
| via GPIO 1 and 2 (TX and RX, respectively) at a baud rate of 115200. Because |
| of this, you'll need a USB TTL adapter to communicate with the Pi Pico. |
| |
| Once the pico SDK is configured, the Pi Pico will build as part of the default |
| GN build: |
| |
| .. code:: sh |
| |
| ninja -C out |
| |
| Pigweed's build will produce ELF files for each unit test built for the Pi Pico. |
| While ELF files can be flashed to a Pi Pico via SWD, it's slightly easier to |
| use the Pi Pico's bootloader to flash the firmware as a UF2 file. |
| |
| Pigweed currently does not yet build/provide the elf2uf2 utility used to convert |
| ELF files to UF2 files. This tool can be built from within the Pi Pico SDK with |
| the following command: |
| |
| .. code:: sh |
| |
| mkdir build && cd build && cmake -G Ninja ../ && ninja |
| # Copy the tool so it's visible in your PATH. |
| cp elf2uf2/elf2uf2 $HOME/bin/elf2uf2 |
| |
| Flashing |
| ======== |
| Flashing the Pi Pico is as easy as 1-2-3: |
| |
| #. Create a UF2 file from an ELF file using ``elf2uf2``. |
| #. While holding the button on the Pi Pico, connect the Pico to your computer |
| via the micro USB port. |
| #. Copy the UF2 to the RPI-RP2 volume that enumerated when you connected the |
| Pico. |
