Announcing Zephyr 4.2

[nashif]

We are pleased to announce the release of Zephyr 4.2.0!

For a detailed overview of some of the highlights of this release, you may check out the dedicated article that was just posted on the Zephyr blog, and its accompanying video:

• https://www.youtube.com/watch?v=25xrHzeaw5w
• https://www.zephyrproject.org/zephyr-4.2-announcement

Major enhancements with this release include:

Initial Support for Renesas RX

The Renesas RX architecture is now supported, including a QEMU-based board target.

USB Video Class Driver

The USB device stack now supports USB Video Class (UVC) allowing camera devices and other image/video sources to be exposed as standard USB video devices. See USB Video webcam to get started.

Twister Power Harness

A new Twister harness enables measurement of the power consumption of the device under test and ensures it remains within a given tolerance.

MQTT 5.0

The networking stack now includes full support for the MQTT 5.0 protocol.

Bluetooth Classic improvements

The Bluetooth Classic stack now includes support for Hands-Free Profile (HFP) for both Audio Gateway (AG) and Hands-Free (HF) roles.

Zbus

The Zbus library graduates to stable status with the release of API version v1.0.0.

Expanded Board Support

Support for 96 new boards and 22 new shields has been added in this release.

An overview of the changes required or recommended when migrating your application from Zephyr v4.1.0 to Zephyr v4.2.0 can be found in the separate migration guide.

The 4.2 release will be supported until March 20th, 2026

Regards,
Dan and Dan, and the full Zephyr Release Team