STM32 SPI Firmware Development

I have a custom board built around an STMicroelectronics MCU and I need a clean, well-structured C firmware that turns the chip into an I2CSPI host. The main job of the code is twofold: first, to issue and interpret I2C/SPI commands that control the connected device’s registers and modes; second, to expose a reliable communication interface so the higher-level application can talk to the hardware without worrying about timing, buffering, or error handling.

Because this board will eventually ship, the code must follow good embedded-design practice: non-blocking state machines, clear separation between driver and application layers, and concise documentation inline and in a short markdown file. You’ll be working directly with GPIOs, clocks, and the peripheral registers, so solid electronics knowledge is important to keep signal integrity and pin configuration in check.

Deliverables:
• Fully-commented C source and header files compatible with STM32CubeIDE (HAL or bare-metal, your choice as long as it is readable and maintainable).
• A brief “getting started” note that shows how to build, flash, and test the firmware on my board.
• Basic validation script or schematic notes that prove SPI timing and logic levels meet spec.

If you have prior experience bringing up I2C/SPI on STM32 parts and can demonstrate tight, production-ready code, I’d like to hear how quickly you can turn around a first build.