2026-04: Key hardware initialization reliability improvements in Zephyr's STM32 PWM driver and robust ARR preload sequencing. The ARR preload generation was refactored to occur during device initialization, ensuring ARR is set only when preload is enabled to prevent errors when the counter is activated. This reduces startup/activation failures and improves runtime stability for PWM peripherals.

February 2026: Focused fix in the STM32 PWM driver to maintain master-slave synchronization during reconfiguration. Avoided an extra update event in center-aligned mode when trigger generation occurs on update, preventing desynchronization between PWM polarity and ADC triggering. Result: more reliable ADC sampling and PWM-driven workflows in Zephyr on STM32.

November 2025 — Zephyr4Microchip/zephyr: Delivered STM32 PWM Master Mode support, along with a sample and robust configuration/binding updates. Implemented a new device-tree binding for master mode, added error handling for unsupported LP timers, and configured master mode during device initialization when supported. Added a sample demonstrating timer/ PWM master mode usage to generate TRGO events to the interconnect matrix, improving deterministic timer signaling. The work enhances PWM timing fidelity on STM32 devices and simplifies developer usage, reducing misconfiguration risk and enabling clearer hardware coordination with the interconnect.

June 2025: Delivered memory-management and stability improvements across two major Zephyr-based repositories, focused on business value and portability. Implemented user-configurable ZBus heap sizing to reduce ROM footprint and improve dynamic buffer handling, with standardized ZBus naming to improve codebase consistency. Added a prohibitive LTO flag in the minimal C library build to ensure critical symbols (e.g., memset, memcpy) remain available, preserving library functionality and build stability. These changes enhance predictability, reduce memory usage, and increase confidence in generated code across platforms.