Every new year I like to think further out about what I want to do in the coming year. 2025 is going to be shaped by lots of bonding time with my second child. They were born at the end of October and I took four weeks off then. This year I plan on taking eight more weeks completely off and then working part time when they nap until they go to daycare when they turn 1. So, like 2022, I’ll be away from CircuitPython for a good chunk of the year. My hope is that I’ll be able to reconnect to CircuitPython and the community when working part time. I truly enjoy working for Adafruit on CircuitPython.
I didn’t really know what 2025 would bring for CircuitPython until Ladyada asked me if there was something we could do to make supporting new chipsets easier. We’d also been thinking about using a real time operating system (RTOS) in CircuitPython to better manage display and audio “background” tasks. Much of my 2024 was spent finishing BLE support of ESP32 chips. It was the third time we’d added BLE support (nRF SD, BLE HCI and now nimble for ESP32). At the end of the year I worked on CircuitMatter. CircuitMatter would benefit from Thread support in CircuitPython too. Thread could also fall into the multiple implementation trap that BLE did too.
So, I proposed that we move CircuitPython onto Zephyr. Zephyr is a real time operating system with a large number of supported chipsets and networking protocols (BLE, Thread, WiFi). Zephyr knows what compiler to use, the compiler flags, the memory layout and attached devices (like flash memory) for many boards. It makes it very easy to get CircuitPython basics going on any Zephyr supported board. In particular, the upcoming Nordic nRF54 and Renesas RA8’s microcontrollers are pretty interesting. After moving to Zephyr, CircuitPython’s build system won’t need to manage basic differences between microcontrollers.
Zephyr’s strong protocol support means we only (fingers crossed) need to add BLE, WiFi, Ethernet and Thread support for Zephyr and then all boards will be supported. The nRF54 in particular supports BLE with Nordic’s Zephyr based SDK. Our existing Nordic BLE support wouldn’t work on it.
The bigger challenge with Zephyr is its reliance on compile time configuration. CircuitPython is very dynamic for pin configuration. Zephyr expects these to be setup at runtime normally. We may need to continue implementing things like `busio` per vendor to keep being dynamic. We already do this today when working with vendor specific SDKs, so it won’t be new work.
Zephyr also supports additional things that we don’t currently in CircuitPython. I mentioned Thread earlier as one of those things. Another is more advanced flash devices like octal spi and (maybe) nand flash. It also supports SDRAM, an inexpensive way of adding MB of more RAM! MIPI-DSI displays, Ethernet, cellular connectivity and I3C are also interesting.
So, my goal in 2025 is to bring more boards to CircuitPython using a new Zephyr port. Throughout 2025 I’ll work to add functionality to the Zephyr port so that it can match the feature set of other ports. Once it does, we can replace the non-Zephyr version with the Zephyr based one. (Hopefully folks won’t miss any functionality.) This should set us up to move to Zephyr everywhere in 2026.
In case you missed it, Ladyada and I discussed CircuitPython2025 on video. I’ve got a bit of the busy parent look in the video even though it was just the toddler and I.
#CircuitPython2025 is our annual reflection on the state of CircuitPython. We’d love to hear from you too! See the kick-off post for all of the details. Please post by January 14th and email [email protected] to let us know so we can link to it.
Past posts:
- CVASchmidt posted on the forum about Python’s
dismodule, Thonny and documentation. - cadet702 posted a Gist about a CircuitPython powered Home Assistant plugin like ESPhome.
- RetiredWizard emailed in discussing display capabilities.
- Dan posted four ideas to the forum.
- Anne posted to Bluesky.
- Scott and Ladyada discussed CircuitPython2025 on video.
- Sam Blenny wrote a Gist about building standalone CircuitPython devices.
- Andrew (aka somenice) posted to their blog about displayio.
- Paul Cutler announced the return of the CircuitPython Show podcast for #CircuitPython2025!
- Anecdata posted to Mastodon suggestions for core enhancements around networking.
- Cooper (aka relic_se) posted to Mastodon excitement for improved audio effects and benefits of the Zephyr work.
- FoamyGuy has posted his CircuitPython2025 as a GitHub Gist.
- @jepler (aka @stylus) posted big news to Mastodon.
- Kick off blog post.
