Add Circuitpython compatibility

[mocleiri]

We should be able to copy the code from ulab which also has circuitpython support. It looks like you need to clone circuit python and then add a two links like this:

micropython-modules/microlite -> extmod/microlite
micropython-modules/audio_frontend -> extmod/audio_frontend

It would be similiar to this:
https://github.com/v923z/micropython-ulab/blob/1d9670096f093eae0a27437943dca088a27cc378/build-cp.sh#L41

We can try to use the version of ulab in circuit python but if that is a problem we can also make a symbolic link from:

micropython-ulab -> extmod/ulab

[mocleiri]

We could implement a unix port build like ulab does but probably we would need to wait for #28 to be implemented before we could target an actual device as that will reduce the firmware size by allowing us to select less operators.

[mocleiri]

There are problems with the Nucleo H743ZI2 Micropython port.

I do have it building but need to build the CI for it and also get the esp32 port working with the new structure which builds tensorflow directly within the micropython submodule.

Once I have esp32 working again I should be able to proceed with the CircuitPython port which would probably have the same issues (board resetting when tflite model is loaded).

Or I may first try to get the rp2040 port working or the teensy4 which are the other circuit python compatible boards I have.

[mocleiri]

The rp2 port works. I should add esp32s2 support and then move forward with the circuitpython integration work.

[AndreasTheCat]

@mocleiri any news regarding any esp32 port?
If there is enough interest in this port I would collaborate. (maybe switch to liteRT)

[uraich]

Yesterday I tried to recompile the esp32 port using the newest micropython version. I got a few compilation errors but adding MP_ERROR_TEXT in mp_raiseTypeError calls was all that was needed to build the system again.
I did not try the camera and and the wake word examples yet but I managed to run the mnist hand-written digits example on the newly built system.

[AndreasTheCat]

@uraich
that's good messages.

As far as I can see is the whole integration based on Micropythons USER_C_MODULES, which is not an available feature in CP?!
Am I completely wrong or is this the exact reason that @mocleiri ended up with?

I did go thru the shared-bindings/shared-module way to expose TF to CP.

After trying many different "approaches" to get TF on CP, which all led to

• ugly makefile-additions
• c/c++-calling issues
• handwritten additions
• "esp-only" via esp-idf-component

(Non of these "ideas" produced an image)

I'm stuck and still fighting to get the first 4 functions from THIS to CP.

Anyway, the awesome people at adafruit / hackster.io etc supported me and gave valuable hints, big shoutout to them <3

Me I'm grateful for any help.