Frame Firmware & RTL Codebase

Welcome to the complete codebase of the Frame hardware. For regular usage, check out the docs here.

System architecture

The codebase is split into three sections. The nRF52 Application, the nRF52 Bootloader, and the FPGA RTL.

The nRF52 is designed to handle the overall system operation. It runs Lua, as well as handle Bluetooth networking, AI tasks and power management. The FPGA meanwhile, simply handles acceleration of the graphics and camera.

Getting started with nRF52 firmware development

1. Open this repository in a Dev Container (you will need Docker installed) and initialize any submodules by running the below from ./:

   git submodule update --init --recursive

2. Run the following from ./:

   make release

3. Download the ./build directory to your local machine.

4. Ensure you have nrfutil installed. You can follow the instructions at this link to install this library onto $PATH.

5. On your local machine with nrfutil installed run:

   nrfutil device recover

6. On your local machine with nrfutil installed in the parent directory where ./build is located run:

   nrfutil device program \
       --options reset=RESET_HARD \
       --firmware ./build/frame-firmware-*.hex

7. The device should now be programmed and running the latest firmware and advertise its Bluetooth name as Frame. You can use a utility such as nRF Connect for iPhone to locate the device and prove it is advertising.

Debugging

1. Open the project in VSCode.

   There are some build tasks already configured within .vscode/tasks.json. Access them by pressing Ctrl-Shift-P (Cmd-Shift-P on MacOS) → Tasks: Run Task.

   Try running the Build task. The project should build normally.

   You many need to unlock the device by using the Erase task before programming or debugging.

2. To enable IntelliSense, be sure to select the correct compiler from within VSCode. Ctrl-Shift-P (Cmd-Shift-P on MacOS) → C/C++: Select IntelliSense Configuration → Use arm-none-eabi-gcc.

3. Install the Cortex-Debug extension for VSCode in order to enable debugging.

4. A debugging launch is already configured within .vscode/launch.json. Run the Application (J-Link) launch configuration from the Run and Debug panel, or press F5. The project will automatically build and flash before launching.

5. To monitor the logs, run the task RTT Console and ensure the Application (J-Link) launch configuration is running.

Getting started with FPGA development

For quickly getting up and running, the accelerators which run on the FPGA are already pre-built and bundled within this repo. If you wish to modify the FPGA RTL, you will need to rebuild the fpga_application.h file which contains the entire FPGA application.

1. Ensure you have the Yosys installed.

2. Ensure you have the Project Oxide installed.

3. Ensure you have the nextpnr installed.

4. MacOS users can do the above three steps in one using Homebrew.

   brew install --HEAD siliconwitchery/oss-fpga/nextpnr-nexus

5. You should now be able to rebuild the project by calling make:

   make fpga/fpga_application.h

To understand more around how the FPGA RTL works. Check the documentation here.