I just wrapped up the core architecture of the drone’s flight controller, including mapping out all 7 interrupt methods into a far more optimized RTOS scheduler. The updated version makes use of a FIFO stack, to keep track of nested interrupts. I also protected the main code from data corruption during pendSV switches by enabling and disabling irq in certain areas of vulnerable code. Other small changes to the assembly to save floating point registers as well as better memory allocation was also done in this update.

From high-speed IMU sensor integration and state estimation calculations to CRSF packet decoding and DShot motor generation, the essential tasks are fully written and compiled. I’ve officially shifted gears into the testing phase, working on simulated environments to debug DMA transfers, registers, and the flight state machine’s arming sequences. As of now, I am writing python scripts by hand, in order to inject “dummy” values into the GPIO, SPI, and USART registers in order to populate the buffers, and simulate the calculations.

As the code is becoming longer and longer, I will try to refactor a lot of the files into smaller more organized portions, to increase readability (often I have a hard time traversing everything).

Note: The current code pushed to GitHub isn’t quite the latest since I’m in the middle of troubleshooting a few simulation-specific register bugs, but I wanted to get this update out to meet the 10-hour devlog requirement on Stardance. Everything is moving in the right direction, and having a virtual environment all working means I can safely verify the PID mixer and safety flags before this code ever touches a physical quad. This officially marks the end of both phases 2 and 3, and now its a matter of finishing extra scheduled telemetry tasks (e.g. OSD and EdgeTX logging), but I estimate that the flight controller portion of the code (around 60% of all logic in the drone) will be done between now and Sunday, July 19th!

I will also post a much more in depth devlog about how the methods work, as well as an updated README.md on Github ASAP.