Arduino Core on Zephyr Work Hits a New Milestone, Prepares to Exit Beta in June

The Arduino team has announced a milestone release for its Arduino Core on Zephyr project, version 0.55.0 — which is likely to be the last beta before the core is marked "stable" and formally launched in June.

"We’re releasing version 0.55.0 of the Arduino Core on Zephyr today, and it's a meaningful one," the Arduino team claims of the new release. "This update resolves one of the most common friction points users have reported, adds support for two widely-used libraries, and brings us noticeably closer to our June target for marking this core 'Stable' and ending the beta program. Concurrently, we'll begin deprecating the corresponding cores based on mbedOS. If you’ve been following the beta, this one is worth updating to."

The move away from Mbed was triggered by Arm's decision to sunset the platform back in 2024 — bad news for Arduino, which had built upon what turned out to be unstable foundations. Zephyr, a fully-open real-time operating system with broad support and had already been the target of 2022 work under the Google Summer of Code program, was picked as the replacement, and progress has been steady ever since.

In this latest release, the Zephyr-based core comes with simplified serial configuration that works in both the Arduino IDE 2 and the Arduino UNO Q- and VENTUNO Q-specific Arduino App Lab integrated development environments. "Serial.println() should just work," the team says of the update. "Print to your monitor without thinking about it."

Other changes include a real-time clock (RTC) function with calendar and network time protocol (NTP) synchronization support, CAN bus support and dynamic interrupts on the Arduino UNO Q, shift-in and -out functionality for serial reads and writes on arbitrary pins, support for Zephyr workqueues for low-priority interrupts, and a range of bug fixes.

Arduino Core on Zephyr 0.55.0 also extends the list of supported boards by one: the new release is compatible with the Arduino Nicla Vision edge computer vision board, along with the existing Nicla Sense, Arduino Nano 33 BLE, Nano Matter, Giga Display Shield, Opta, Portenta C33, Portenta H7, and UNO Q.

Those with compatible boards can upgrade to the new core through the Arduino IDE Board Manager now, with additional information available on GitHub alongside the source code under the permissive Apache 2.0 license. If you're installing it on an Arduino UNO Q, meanwhile, consider entering our Invent the Future with Arduino UNO Q and App Lab contest for a chance to win a share in a $20,000 prize pool.