using _all_channels to update efficiently

[garyk10]

When not changing between low and high, the channel#_data was not being updated. Also, the clear and nir data is available when _low_channels_configured, so no need to change to high.

[tekktrik]

Do you need to "get" _all_channels? The CI is angry since it thinks it's a "pointless statement". You may need to assign the result to underscore (e.g. _ = self._all_channels) or disable the pylint warning for it in that case.

[FoamyGuy]

I pushed a commit to catch the return from all_channels into _ as mentioned.

The specifics of this change are a bit over my head. Hoping we can have someone with more knowledge weigh in, or at least with hardware to try it out.

[garyk10]

Thanks for the change. The only hardware I have tried is with a Raspberry Pi Zero and a Raspberry Pi 3B connected to the AS7341 via SDA/SCL pins, using Python 3.9 or 3.10. I haven't tried any microcontrollers using MicroPython to do this.

[jedgarpark]

I've experienced a similar issue in CircuitPython running on a Feather RP2040 and attempting to read only the clear channel. It does not update unless i am also reading other channels.

[FoamyGuy]

This looks good to me.

Thank you @garyk10 for this improvement!

I tested this successfully on on a Feather S3 TFT. Confirmed the currently released version does not update clear reading unless other readings are taken too. And this PR version does successfully update clear readings even if no other readings are taken.