// the find
pms67/LittleBrain-STM32F4-Sensorboard
STM32F4-based PCB interfacing with a variety of sensors.
A complete STM32F405-based sensor board with KiCad hardware files, BMI088 IMU and SPL06 barometer drivers, an EKF implementation, and FIR/RC filter code. It exists primarily as companion material to a YouTube tutorial series on designing and programming your own STM32 PCB. The target is someone learning embedded hardware design who wants a working reference they can order from JLCPCB.
The EKF implementation alongside the sensor drivers is a meaningful pairing — you get the full signal processing chain from raw IMU data to fused attitude estimate, not just a driver stub. Two firmware variants ship (bare-metal and FreeRTOS), which makes it actually useful as a learning comparison rather than a one-trick example. Hardware and firmware live in the same repo with matching Gerber/BOM files, so the gap between schematic and running code is smaller than most similar projects. The BMI088 and SPL06 drivers use SPI with HAL and are self-contained enough to lift into another project.
The repo is abandoned as of September 2021 and the STM32F405 is showing its age for new designs — STM32G4 or H5 would be more sensible starting points today. Compiled Debug artifacts (.o, .d, .su, .bin, .elf) are committed to git, which is sloppy and inflates the clone size for no reason. The EKF has no accompanying explanation of the state vector or tuning parameters, so it's hard to adapt without reading the math cold. There's no schematic PDF exported — you need KiCad installed to see the actual circuit, which raises the barrier for the people most likely to benefit from this.