sat-rs/satrs-example-stm32f3-disco/README.md

sat-rs example for the STM32F3-Discovery board

This example application shows how the sat-rs framework can be used on an embedded target. It also shows how a relatively simple OBSW could be built when no standard runtime is available. It uses RTIC as the concurrency framework and the defmt framework for logging.

The STM32F3-Discovery device was picked because it is a cheap Cortex-M4 based device which is also used by the Rust Embedded Book and the Rust Discovery book as an introduction to embedded Rust.

Pre-Requisites

Make sure the following tools are installed:

1. probe-rs: Application used to flash and debug the MCU.
2. Optional and recommended: VS Code with probe-rs plugin for debugging.

Preparing Rust and the repository

Building an application requires the thumbv7em-none-eabihf cross-compiler toolchain. If you have not installed it yet, you can do so with

rustup target add thumbv7em-none-eabihf

A default .cargo config file is provided for this project, but needs to be copied to have the correct name. This is so that the config file can be updated or edited for custom needs without being tracked by git.

cp def_config.toml config.toml

The configuration file will also set the target so it does not always have to be specified with the --target argument.

Building

After that, assuming that you have a .cargo/config.toml setting the correct build target, you can simply build the application with

cargo build

Flashing from the command line

You can flash the application from the command line using probe-rs:

probe-rs run --chip STM32F303VCTx

Debugging with VS Code

The STM32F3-Discovery comes with an on-board ST-Link so all that is required to flash and debug the board is a Mini-USB cable. The code in this repository was debugged using probe-rs and the VS Code probe-rs plugin. Make sure to install this plugin first.

Sample configuration files are provided inside the vscode folder. Use cp vscode .vscode -r to use them for your project.

Some sample configuration files for VS Code were provided as well. You can simply use Run and Debug to automatically rebuild and flash your application.

The tasks.json and launch.json files are generic and you can use them immediately by opening the folder in VS code or adding it to a workspace.

Commanding with Python

When the SW is running on the Discovery board, you can command the MCU via a serial interface, using COBS encoded PUS packets.

It is recommended to use a virtual environment to do this. To set up one in the command line, you can use python3 -m venv venv on Unix systems or py -m venv venv on Windows systems. After doing this, you can check the venv tutorial on how to activate the environment and then use the following command to install the required dependency:

pip install -r requirements.txt

The packets are exchanged using a dedicated serial interface. You can use any generic USB-to-UART converter device with the TX pin connected to the PA3 pin and the RX pin connected to the PA2 pin.

A default configuration file for the python application is provided and can be used by running

cp def_tmtc_conf.json tmtc_conf.json

After that, you can for example send a ping to the MCU using the following command

./main.py -p /ping

You can configure the blinky frequency using

./main.py -p /change_blink_freq

All these commands will package a PUS telecommand which will be sent to the MCU using the COBS format as the packet framing format.