Open Source Summit North America 2025

When seeking to use Rust for embedded development, there are several options, including bare-metal, a few rust-specific rtos implementations, and several existing RTOSes. This talk discusses why Zephyr is a good fit for an embedded Rust, and especially how we are able to leverage some of Zephyr's strengths, including a rich and diverse set of supported targets, and some of Zephyr's features, such as the work queue mechanism, and how it fits well with Rust's async system.

This talk would highlight the importance of open source health devices and how we used Zephyr across several hardware platforms to develop these devices. We will draw on experiences from our projects including HealthyPi 5, HealthyPi 6 and the wearable HealthyPi Move, all open source hardware and software. More specifically how Zephyr enabled the use of practically a single codebase across three different microcontroller platforms in different form factors.

l will also talk about the challenges faced during the process of making the system wearable and low power and the solutions that worked for us.

The FUOTA (Firmware Update Over-The-Air) specification(s) from LoRa Alliance make up the framework that underpins the critical task of firmware updates of end points (typically battery operated sensors and actuators) that communicate using the LoRaWAN protocol.

The fundamental limitation of the FUOTA specification, as it exists today, is that it does not expect Firmware Artifacts to exceed a few hundred KB in size. With the increasing adoption of the Zephyr RTOS, along with more sophisticated capabilities being added to the end device, artifact sizes have quickly grown to 500 kB (and beyond). This limitation quickly starts to have a real impact, especially as the cost of doing so called 'drive by' updates (using BLE or other higher throughput transports) can get prohibitive.

We present a novel solution to this problem, leveraging the existing and well supported Device Firmware Update (DFU) specification.

In our solution, the LORAWAN protocol becomes another type of SMP transport (along with the already supported Shell, Bluetooth and UDP). We have extended the open source smpclient library from intercreate, as well as the open source LBM stack from Semtech to achieve this.

RTIO is a relatively new subsystem in Zephyr, and it enables applications to perform time-critical I/O operations.

This presentation covers:
- Basics of RTIO.
- Async vs Sync paradigms.
- In-tree examples of RTIO: Sensors and Bus drivers.
- Integration guide: how to use RTIO in your Zephyr application.
- Demo: Comparison of Sensor driver with RTIO vs without RTIO.

This presentation is for you:
- You want to learn about RTIO.
- You struggle at achieving real-time performance in Zephyr applications.
- You want to optimize performance of your existing application.

The Zephyr Project is a leading open-source RTOS for resource-constrained, real-time applications. Its modularity, vendor neutrality, and rich ecosystem make it a powerful choice for embedded developers. However, achieving peak performance requires a deep understanding of Zephyr’s internals and optimization strategies.

This session explores techniques to optimize Zephyr applications for efficiency, low latency, and real-time predictability. Attendees will learn how scheduling, memory management, and interrupt handling impact performance and how to fine-tune these elements for specific workloads. We’ll cover configuring Zephyr for high-performance execution, reducing runtime overhead, and debugging bottlenecks.

Key topics include:
• Zephyr’s scheduling model and task prioritization
• Optimizing interrupts and reducing latency
• Fine-tuning memory management and resource allocation
• Profiling and debugging performance issues
• Advanced optimizations for power efficiency and I/O

Whether you’re developing for IoT, industrial automation, or real-time control, this session will equip you with practical strategies to maximize Zephyr’s performance and reliability.