Embedded Stm32 Hal (.cursorrules)

{
    "prompt": "# Embedded MCU, STM32, and HAL Rules ## Project Structure - Keep board support, drivers, middleware, application logic, and tests separate. - Isolate generated CubeMX or vendor code from hand-written application code. - Put hardware abstraction behind narrow interfaces so logic can be tested without hardware. - Document clock tree, pin mappings, peripheral ownership, and interrupt priorities. ## STM32 HAL and Peripherals - Initialize peripherals in one place and avoid hidden reconfiguration. - Check return values from HAL calls and handle timeout/error cases. - Keep blocking HAL calls out of time-critical paths. - Use DMA for high-throughput UART, SPI, I2C, ADC, or timer capture paths when appropriate. - Document buffer ownership and lifetime for DMA operations. - Use `volatile` only for memory shared with ISRs or hardware registers. ## Interrupts and Concurrency - Keep ISRs short and deterministic. - Defer heavy work from interrupts to the main loop, RTOS task, or event queue. - Protect shared data with critical sections, atomics, queues, or RTOS primitives. - Avoid dynamic allocation in interrupts. - Make interrupt priority decisions explicit. ## Memory and Timing - Avoid heap allocation in firmware unless the project explicitly allows it. - Check stack usage for ISRs and RTOS tasks. - Keep lookup tables `const` so they can live in flash. - Use fixed-width integer types for hardware-facing code. - Add timeouts for hardware waits. - Treat watchdog configuration as part of application design, not a late add-on. ## Testing and Debugging - Unit test pure logic on host builds. - Use hardware-in-the-loop tests for peripheral behavior. - Add assertions for impossible hardware states in debug builds. - Use SWD/JTAG, logic analyzers, and serial logs with rate limits. - Keep fault handlers useful: capture reset reason, fault registers, and build version when possible. ## Common Mistakes - Do not modify generated files unless the workflow preserves changes. - Do not busy-wait forever on hardware flags. - Do not share buffers between DMA and CPU without synchronization. - Do not assume peripheral reset state after low-power modes.",
    "model": "Claude 3.7 Sonnet / Cursor",
    "aspect_ratio": "1:1",
    "category": "Automation",
    "content_type": "workflow_template",
    "surface": "workflows",
    "quality_score": 83,
    "provenance": "SYSTEM_RULE"
}