Did anyone managed to read CANBUS without canbus peripheral? (softcanbus)

[Javier1]

Is there any way for chips without the Canbus peripheral to read canbus?

No external chips allowed

Maybe uart or bitbanging gpios?

[Tesla DeLorean]

No, better things to do...

If you're willing to grind through the data, you can basically create a logic-analyzer via TIM+DMA+GPIO, sampling fast enough so you can synchronize to the edges, and then step the buffer to extract the HI/LO pairs at the center/sample points, etc. It doesn't look to be overwhelming complex, although perhaps limited in upper bandwidth.

[Michal Dudka]

Or you can use timer input capture + DMA to take timestaps for rising and falling edges. That should be able "read" speeds over 1Mb/s.

[Uwe Bonnes]

Canbus needs collision handling during the burst. So capture and evaluation afterwards is doomed for failure in the field. Bitbanging the protocoll with highest priority for a low bit rate should be doable, but will require a lot of work and understanding of the protocoll and its niches