CircuitPython support

[jonnor]

CircuitPython is a very popular Python-for-microcontrollers. https://circuitpython.org/
It would be nice if that could be supported in addition to MicroPython.
Preferably in a way that has minimal divergence/extra ongoing work to support.

[jonnor]

Right now we primarily use MicroPython native modules, and that works quite well. In order to use the same strategy with CircuitPython, we would need adafruit/circuitpython#6040 to go in.

[jonnor]

The only documentation I have found for extending CircuitPython in C is https://learn.adafruit.com/extending-circuitpython and that is not updated since 2019 - with notes that there are known incompatible changes since then. So it will be use-the-source-Luke.

It seems that for user-modules there is still an open issue in CircuitPython, adafruit/circuitpython#2825
Though it is stated that "it is possible". One user has reported a problem with it, unclear if is a blocker for all usages. adafruit/circuitpython#5910

So it seems that in the short-term the officially supported way is to create an in-tree module that is built as part of upstream CircuitPython. It seems possible to have a separate repository that is pulled into the main build process. https://github.com/adafruit/circuitpython-ulab is probably the most relevant example. And the commits there are probably a good indicator of the difference that are needed to adapt to CircuitPython.

[tannewt]

The only documentation I have found for extending CircuitPython in C is https://learn.adafruit.com/extending-circuitpython and that is not updated since 2019 - with notes that there are known incompatible changes since then. So it will be use-the-source-Luke.

We're happy to help you get going on the CP internals. The best place to get guidance is the Adafruit Discord in the #circuitpython-dev channel. Adafruit-funded CP devs are there usually during US business hours. Volunteers are also there at other times.

[jonnor]

Thank you @tannewt ! I am in the Adafruit Discord already. I will make sure to reach out if I find time to work on this :)