OBAL and STM32 i2c Slave Interface

[jkieffer72]

Greetings. I recently learned of OBAL and then saw the videos with an STM32 "black pill" being used as an i2c slave with connections for RC Input/Output ADC. I am very interested in this code for integration into some of my projects.

I have been riding the struggle bus so far with some detours along the way. I did manage to get ArduRover built and installed on my Pi4b, along with the sensors and assorted modules.

I have also built several target firmwares for some existing flight controllers I was hoping to recycle. I compared the code/settings for a couple of F7 and F4 based boards I have. (OMNIBUSF4, OMNIBUSF7, JHEF7DUAL) I think I am on the right track, but have not been able to make a connection between the Pi and the STM32. THe firmware(s) for the controllers seems to compile and flash OK. However, I am not seeing the device when I run i2cdetect. I have had a few variations of not working. EIther No i2c devices are detected, or my compass/baro are detected but no STM32 (x66) listed. or, I get a device listed at every possible address.

I get similar results across the three boards I have tried. I am sure I have something incorrectly programmed, just need to figure out what.

Has anyone experienced similar and have a fix? I am not sure how exactly to share and submit my changes for review. I have to focus elsehwere for a while, but will be back to this later today and into the weekend and will update if things change.

[HefnySco]

I hope you find my article useful:

https://medium.com/@mohammad.hefny/ardupilot-linux-based-board-stm32-as-a-breakout-module-5b57989863ce