Arduino Core on Zephyr 0.90.0 is officially stable and leaving beta

Arduino Team — July 29th, 2026

We are thrilled to announce the release of version 0.90.0 of the ArduinoCore-zephyr. This is a major milestone: we are officially exiting the beta phase and marking the core as stable. Achieving this goal is the culmination of months of testing, architectural refinement, and community feedback.

As we establish this core as our primary framework for advanced hardware, we are also beginning the deprecation phase for the corresponding legacy cores based on mbedOS, which has just now reached End of Life status.

Join us in this next chapter! Compile your existing sketches with version 0.90.0, and let us know how it performs.

Expanded board and hardware support

Welcome, Nano RP2040 Connect! The Arduino® Nano™ RP2040 Connect board officially joins our lineup. You can now leverage the full RTOS power of Zephyr on RP2040 hardware with standard Arduino API compatibility.

SD card support for the Arduino® Portenta™ H7 and C33 boards. Native SD card support is now enabled for both Portenta H7 and Portenta C33, making it simple to log data and host local files on external memory.

PDM library support. Official support for the PDM library on the Nano 33 BLE board is here, unlocking digital microphone input for audio sampling, noise detection, and edge AI voice processing.

Universal automatic loader sync

With version 0.90.0, automatic loader-and-sketch synchronization is now enabled across all supported boards. The core automatically verifies and handles loader updates behind the scenes during every sketch upload. This means you can simply open the Arduino® IDE, connect a board running a sketch based on mbedOS, switch to the new Zephyr-based core, and upload your sketch. The IDE will automatically update the loader as needed to ensure compatibility with Zephyr.

If you are running Zephyr for the first time, check out our step-by-step guide here.

Full hardware compatibility list

How to get started

To update your environment: open the Arduino IDE, search for “zephyr” in the Board Manager, and install version 0.90.0.

Thank you!

This stable milestone wouldn’t be possible without our community. Check out the full release notes on GitHub, report issues, and help us build the next era of Arduino on Zephyr!

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