Zephyr Brings the SiWx917 Ultra-Low-Power Wi-Fi to Everyone

With the Q2 release of Simplicity SDK for Zephyr, support for the SiWx917 is expanding. This is a meaningful step forward and provides developers a more mature Zephyr path for building with the SiWG917, supported by continued validation with a focus on product development.

This release offers an opportunity to take a fresh look at the SiW917 and what it represents for manufactures of energy-sensitive IoT devices. A key feature is that the SiWx917 brings together ultra-low-power Wi-Fi, Bluetooth Low Energy (LE), and application processing integrated on one device. In this blog, we’re going to take a closer look at what the SiWx917 + Zephyr means for developers.

The General Availability of Simplicity SDK for Zephyr Represents Full Quality Assurance

The quality levels associated with Simplicity SDK for Zephyr map to concrete commitments and provides insight into a fully tested development tool. These levels include:

• Feature completeness - a complete implementation of the documented feature set, not a partial preview.
• Verification - fully verified according to the test plan, rather than the incomplete verification that defines earlier stages.
• Bug and security fixes - critical fixes land in the latest GA release as well as the development branch.
• Technical support - issues in tagged releases raised through Silicon Labs support channels are handled by our support staff.

The Industry’s Leading Ultra-Low-Power Wi-Fi Device, Now With the Flexibility of Zephyr

If you’re unfamiliar with the SiWx917, or haven’t looked closely at it lately, here’s why this is interesting. The SiWx917 is an ultra-low-power Wi-Fi 6 + Bluetooth LE 5.4 wireless SoC with an integrated Arm Cortex-M4F application processor (up to 180 MHz), radio, and security — all in a single 7x7 mm package. It’s available with as much as 8 MB of in-package Flash and includes a full complement of digital and analog peripherals.

It’s built for the kind of devices where battery life and board space are at a premium, including smart home sensors, wearables, connected health, asset tracking, and industrial IoT devices. On Zephyr, the SiWx917 is supported as a wireless SoC, giving developers a flexible path for building connected applications on a single device. Now all of that is available with the flexibility of Simplicity SDK for Zephyr.

Bringing the SiWx917 to GA brings much of its Wi-Fi capability into production-ready Zephyr environments. On Zephyr, the SiWx917’s Wi-Fi feature set covers the core requirements real products depend on, including reliable connectivity, security, power-aware operation, and the flexibility needed to support connected devices across a range of IoT use cases.

• Station (STA) mode for connecting to existing networks
• Access Point (AP) mode for provisioning and standalone deployments
• Power Save modes for battery-sensitive designs
• Target Wake Time (TWT) - the Wi-Fi 6 scheduling feature that lets a device negotiate exactly when it wakes to talk to the AP, a big lever for low-power operation

These features have been through additional levels of testing and a few capabilities continue to mature at earlier quality levels, so the Quality Levels page remains the authoritative, feature-by-feature reference — always worth checking against your specific design.

Broad Bluetooth LE Support for Multi-Protocol IoT Designs

The SiWx917 isn’t just a Wi-Fi part, and its Bluetooth LE support moves to GA in this release as well. The Bluetooth LE feature set on Zephyr is genuinely broad and includes:

• PHYs: 1 Mbps, 2Mbps and Coded PHY
• Advertising: legacy, extended, and periodic advertising, plus advertising extensions
• Scanning: active and passive
• Roles: concurrent roles and Data Length Extensions
• Connectivity: L2CAP connection-oriented channels and Enhanced ATT
• Security and privacy: LE privacy, LE security mode 1 (levels 1–4) and mode 2, LE Secure Connections, Just Works and Passkey Entry pairing, and Out-of-Band support

That’s enough to build modern, secure Bluetooth LE applications, from simple peripherals to more sophisticated multi-role designs, on the same chip handling your Wi-Fi.

Why Zephyr SDK Support for the SiWx917 Matters

The appeal of the SiWx917 has always been the combination of capabilities: Wi-Fi 6, Bluetooth LE, and an application MCU. What the Q2 release changes is the foundation you build that combination on. A GA-quality Zephyr target means a complete feature set, full verification against the test plan, and a real support path — the things you need to take a design from prototype to production with confidence.

The full, feature-by-feature breakdown of quality levels for Wi-Fi, Bluetooth, drivers, security, and bootloaders lives here: Quality Levels — Simplicity SDK for Zephyr.