Add to can docs

[anfroholic]

Hi IhorNehrutsa,

Thanks for your work adding to the can code base. I recently compiled your fork and it seems to be working great. I'd love to help out. I have a fair amount of experience with the can functionality of the stm32 version.

Let me know what your goals are and I will do what I can.

Thanks
Andrew

[IhorNehrutsa]

@anfroholic Hi Andrew. Thank you very much.
I am very sorry that somehow I missed your PR at the time.
I would be very grateful for your help.
I merged your PR and rebase WIP: esp32 CAN(TWAI) driver #7381 and
now I'm not completely sure what all is Ok with the PR.

1. Could you recheck the build and review code and docs? Please report to WIP: esp32 CAN(TWAI) driver #7381
2. There is a compatibility/consistency issue between STM32 and ESP323 CAN API. Could you compare and confirm the differences between STM32 and ESP323 CAN API and help(rst) files? It will be great.
3. I also try to develop CANopenNode drivers
   for STM32 WIP: Canopen #106.
   It is not tested yet. :(
   Is it interested for you?
4. I want to add CANopenNode to MicroPython ports STM32 and ESP323. Your help is welcome.

Thanks, Ihor

[anfroholic]

Hi Andrew. Thank you very much.
I am very sorry that somehow I missed your PR at the time.
I would be very grateful for your help.

No problem, thanks for your work.

1. Could you recheck the build and review code and docs? Please report to WIP: esp32 CAN(TWAI) driver ESP32: CAN(TWAI) driver micropython/micropython#7381

This branch? (pr/5310), sorry I am not very fluent with github.

2. There is a compatibility/consistency issue between STM32 and ESP323 CAN API. Could you compare and confirm the differences between STM32 and ESP323 CAN API and help(rst) files? It will be great.

Sure. I think I can do that. I haven't seen this document before https://github.com/IhorNehrutsa/micropython/blob/pr/5310/docs/library/machine.CAN.rst and will mark it up to date.
The main differences to start are:

1. ESP32 uses baudrate instead of ('sjw', 'bs1', and 'bs2') also there is no prescaler. I'm not sure how/if these can be reconciled. For simplicity's sake, it would be nice if the stm32 version would just adopt the 'baudrate' argument and than hand off applicable timing arguments to the controller under the hood.
2. Filters: The ESP actually has only 1 filter so there is no filter banks to speak of. Also the way the banks are constructed are a little different as pyb.can takes int as arguments
3. can.send: pyb.can will take a string, while this version takes a list of bytes

I also try to develop CANopenNode drivers
for STM32 WIP: Canopen micropython#106.
It is not tested yet. :(
Is it interested for you?
I want to add CANopenNode to MicroPython ports STM32 and ESP323. Your help is welcome.

I am working on something a little different, so that is not what I'm looking for. I'd be happy to offer my opinion on anything if you'd like to hear it.

Thanks again
Andrew

[IhorNehrutsa]

This branch? (pr/5310), sorry I am not very fluent with GitHub.

Please work(comment) with the
WIP: esp32 CAN(TWAI) driver #7381
7381 has actual data

Quickrefs are
https://github.com/micropython/micropython/blob/111247b948a47bb2c77f555e22ac7fbff3312551/docs/esp32/quickref.rst
and
https://github.com/micropython/micropython/blob/master/docs/pyboard/quickref.rst

Library helps are
https://github.com/micropython/micropython/blob/111247b948a47bb2c77f555e22ac7fbff3312551/docs/library/machine.CAN.rst
and
https://github.com/micropython/micropython/blob/master/docs/library/pyb.CAN.rst