The Simplicity SDK for Zephyr delivers the full power of the Zephyr Real-Time Operating System (RTOS) combined with the quality assurance, reliability, and white-glove support Silicon Labs is known for.

Delivered as a downstream, fully QA’d version of the Zephyr codebase, this SDK provides a stable foundation for developing Bluetooth–enabled IoT devices across Silicon Labs’ hardware portfolio — including EFR32 -xG22, -xG24, -xG27, and -xG29.

As a Platinum member of the Zephyr Project under the Linux Foundation, Silicon Labs actively shapes the project’s roadmap and contributes to long-term sustainability. By aligning open-source innovation with Silicon Labs’ rigorous software standards, developers gain a production-ready Zephyr experience with the same high-quality support available for all Silicon Labs SDKs.

Key Features

?Fully Qualified and Supported Release - Every version of the Simplicity SDK for Zephyr undergoes Silicon Labs’ comprehensive QA process, ensuring stability, performance, and long-term reliability.

?Bluetooth Support - Supports Bluetooth LE across EFR32 Series 2 devices, enabling a broad spectrum of connected applications.

?Seamless Migration Path -?Zephyr developers can migrate existing applications to Silicon?Labs?devices with minimal firmware changes,?leveraging?familiar APIs and frameworks.

?Integrated Peripheral and Stack Support - Includes proven peripheral drivers and wireless stacks to simplify application development and reduce bring-up time.

?White-Glove Silicon Labs Support - Backed by industry-leading technical support, extensive documentation, and community engagement — bridging open-source flexibility with enterprise-grade assistance.

Why Choose Simplicity SDK for Zephyr

• Accelerate Time-to-Market
  Develop, test, and deploy faster using an SDK built on the Zephyr ecosystem — no need to reinvent or refactor existing codebases.
• Lower Development Barriers
  Streamlined setup, familiar APIs, and a curated set of examples reduce the learning curve for first-time Silicon Labs users.
• Confidence in Quality
  Each release inherits Silicon Labs’ long-standing commitment to quality and security, ensuring predictable performance across platforms.
• Unified Open-Source Experience
  Enjoy the advantages of open development and collaboration without compromising on stability or support.

What Do Customers Need to Do to Get Access to Zephyr Repos Today?

Everything is available on GitHub, and the entire repository is open source, so no special access is needed. Anyone can freely download it and start their project.

Upstream: https://github.com/zephyrproject-rtos

Downstream: https://github.com/SiliconLabsSoftware/zephyr-silabs

How is Simplicity SDK for Zephyr Different from Simplicity SDK?

Simplicity SDK for Zephyr is an MCU-independent platform, so any MCU vendor can be used for a single project. Zephyr also provides pre-implemented services, such as MQTT, and various device drivers, like LCD displays, making them very easy to use.

The Simplicity SDK, on the other hand, is tailored specifically for Silicon Labs products. Therefore, if someone aims to achieve the best performance — for example, the lowest current consumption — the Simplicity SDK is the better choice.

What Product Features are Currently Supported within Zephyr?

The majority of the peripherals, BLE and proprietary. However, there are some Silicon Labs–specific peripherals and features that are currently not supported in Zephyr, such as PRS or UART oversampling.