Worked on the zephyrproject-rtos/zephyr repository to enhance device stability and expandability for STM32 SPI-based peripherals. Delivered a new DS1302 real-time clock driver supporting SPI in half-duplex mode, enabling reliable timekeeping functionality for embedded systems. Addressed a critical issue by fixing an infinite loop hang in half-duplex master RX mode, introducing a safety condition to disable the SPI function when necessary. The work involved C programming and device driver development, focusing on robust embedded systems integration. These contributions improved both reliability and feature support for customers using SPI peripherals, demonstrating a methodical approach to driver development and bug resolution.