Month: 2026-03 | Repository: nxp-upstream/zephyr Key features delivered: - I2C frequency tolerance-based SCL compliance: corrected I2C frequency calculation using peripheral clock tolerance and added per-instance clock tolerance property to ensure SCL frequency remains within specified limits, improving reliability of I2C communication. Major bugs fixed: - None reported this month. Overall impact and accomplishments: - Increased reliability of I2C communications by ensuring SCL frequency adheres to per-instance tolerances, reducing timing-related errors across board and improving interoperability with Nordic i2c master driver. - Contributed alignment with hardware spec expectations, enabling safer integration in systems with clock tolerance variations. Technologies/skills demonstrated: - C driver development for i2c_nrfx_twim, device-tree (DTS) changes, and clock tolerance calculations. - Kernel development practices: signed-off commits, code hygiene, cross-repo collaboration (NXP-Nordic contributions). - Documentation and change-tracking to support upstream review and maintenance.

February 2026 monthly summary for nrfconnect/sdk-nrf: Implemented regression tests to validate peripheral register reset after boot and bootloader, ensuring PUBLISH and SUBSCRIBE registers are cleared to avoid leftover configurations that could cause runtime errors. Added quarantine tests to detect PPI leftovers post-boot, strengthening boot sequence reliability and overall system stability.

December 2025 monthly summary: Delivered reliability improvements to HAL Nordic examples and expanded testing coverage for nRF54L15 DK. In sdk-zephyr, fixed SPIM+SPIS and TWIM+TWIS issues in the hal_nordic hardware abstraction layer, with commits fbabee3e816953726b564c358029bd49b01dd47e and e68ae84e5b5802e2d08a2b9f290d3df2f32d3e63, included in upstream PR #100453. In sdk-nrf, relaxed quarantine to include SPIM+SPIS and TWIM+TWIS examples for nRF54L15 DK, enabling broader testing and faster iteration (commit eb4cb75a2b7c42c8cbfacc3a1960ff8553156bf3). These changes boost HAL reliability, accelerate developer onboarding, and broaden QA coverage across both repos, with active upstream collaboration.

October 2025: Delivered crucial header include fixes for Nordic nRF ADC and I2S drivers across Zephyr repositories, restoring stable operation by addressing memory region assertion failures. Implemented cross-repo fixes in zephyrproject-rtos/zephyr and nrfconnect/sdk-zephyr, reducing driver instability and enabling reliable Nordic SoC driver usage.

September 2025 performance summary: Focused on reliability and maintainability improvements across flash disk and NRF GRTC timer components. Implemented proper error propagation for disk write operations and introduced a dedicated enable-status check function for the GRTC timer channel, aligning with nrfx usage and improving code readability. Worked across multiple repositories to enhance diagnostics, stability, and maintainability of disk and timer drivers.

August 2025 monthly summary focusing on stabilizing QDec test suites for nRF54L15 and improving cross-repo test reliability. Implemented test cleanup between runs, ensured emulation shutdown, and reset of semaphores to eliminate race conditions and align hardware test behavior, enabling more consistent CI feedback and hardware-agnostic stability.

July 2025 highlights across nrfconnect/sdk-zephyr, nrfconnect/sdk-nrf, and zephyrproject-rtos/zephyr-testing focused on strengthening build reliability, memory safety, and test coverage for Nordic platforms. Key improvements include memory-regions safety for DMM-enabled Nordic drivers, enhanced memory-region handling for UART in NRF54H20 samples, and greater build flexibility through NRFX_DIR configurability in Sysbuild. Expanded hardware testing coverage adds sense-edge GPIO validation on NRF54L15DK and robust QDEC multi-instance validation across boards, supported by a multi-device QDEC test framework and new device-tree loopback bindings. These changes collectively improve build stability, reliability of Nordic peripherals, and the breadth of automated testing across supported hardware, enabling faster, lower-risk releases.