ST announces Zephyr 4.4.0 is adding support for the STM32C5, STM32H5E/F, STM32U3C5, as well as the X-NUCLEO-IKS5A1 daughter board, the EVKITST87M01-1 evaluation kit, and the ST B-DSI-MB1314 touch-sensitive display, among many other things, such as sensors and modems (ST87M01). It’s a testament to the collaboration between ST and the Zephyr community. Over the years, ST prevail drivers, optimize performance, and supports new features. And while we do have partners who use Zephyr and benefit from these contributions, this also stems from our desire to work with open-source projects that help democratize real-time operating systems and lower the barrier to entry.
The ST software ecosystem, encompassing the STM32Cube suite and tools like MEMS Studio, provides engineers with low-level device access and accessible machine learning capabilities. Through utilities such as NanoEdge AI Studio, the company facilitates edge AI development and optimizes hardware accessibility for a broad user base. For more insights, visit the ST Blog.
STM32Cube Ecosystem and the other ST software that grant developers low-level access to devices, such as MEMS Studio, which makes machine learning on sensors even more approachable. For many, tools like STM32CubeProgrammer help make the hardware more accessible, while ST’s software packages for its microcontrollers, microprocessors, sensors, and more provide drivers, middleware, example code, and more. Recently, utilities like NanoEdge AI Studio help programmers and software engineers work on neural networks and optimize their AI applications at the edge, thanks to features like synthetic data generation.
The Zephyr project provides a necessary, agnostic system for organizations managing diverse hardware, offering a unified abstraction layer that enhances portability and interoperability for complex, multi-vendor projects. By utilizing this open-source platform, developers can establish a flexible foundation for building proprietary subsystems and avoid vendor-specific lock-in. You can read the full analysis at ST’s official website.
The importance of the collaboration between ST and Zephyr
ST contributes to the Zephyr project and supports its low-level APIs. Concretely, it means we work with Zephyr to support numerous peripherals and interfaces, including USB modules, LCD-TFT display controllers, networking interfaces, and much more. Since the beginning of the Zephyr project, ST engineers have contributed to the Zephyr codebase and the support community. In certain instances, we even help with critical technologies, such as low-power modes, recognizing that our contribution will benefit more than just the engineers using our products. Another aspect of ST’s work on the Zephyr project is the significant effort that involves reviewing community contributions to the STM32 codebase. It may include new board support, bug fixes, and even complete drivers pushed and maintained by external contributors. Over time, these contributions have been responsible for a significant part of the STM32’s current status.
New MCU Support
The STM32N6 Discovery Kit with a CMOS sensor running a person detection application. Zephyr 4.4.0 is a good example of dedication to the project. Similar to frequent updates to STM32CubeProgrammer bringing new STM32 MCU support, this new version of Zephyr adds support for the STM32C5, STM32H5E/F, the STM32U3C5, and the STM32WBA2X. In some instances, like the STM32C5, this version adds support for DMA, I2C, SPI, ADC, timers, and watchdog. Since we just launched the STM32C5, Zephyr 4.4.0 is an inaugural release for the new series. For other devices in an existing series, the MCU support builds on what is already in place, enabling developers to leverage new part numbers.
New Middleware Features
Beyond the device itself, ST also brings updates to its drivers or middleware. For instance, among many improvements, v4.4.0 brings performance enhancements on STM32, adds RTIO and optimizes DMA in SPI STM32 drivers, and adds a stream API for ADC STM32 drivers. We also added the ability to inject ADC channels to enable immediate execution, overriding the regular sequence. Similarly, Zephyr 4.4.0 adds a portable API to read the one-time programmable non-volatile memory on STM32 MCUs. Usually, that means an ADC sensor can now access calibration data. We are also starting to make our I3C interfaces available on our STM32MP2 MPU, and we have moved our USB default stack to a newer and more robust version.
The article is originally written by STMicroelectronics. For more details, go through this link https://blog.st.com/zephyr/

