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@LukasLendvorsky LukasLendvorsky commented Dec 11, 2025

When running in CAN-FD mode, but with same nominal and data baudrate (just 64B data payload, but without transmitting data faster), BRS bit has to remain at zero. That indicates that there is no bitrate switch happening for data and data is transmitted at same speed.
If I send message with BRS=1, even with data & nominal speed configured the same, I get framing errors on the bus. Even single message like this kills my whole bus.

This introduces option to do that via uavcan.udp.disable_brs set to true, or determines this automatically when uavcan.udp.bitrate indicates same bitrate for header & data.

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coveralls commented Dec 11, 2025

Coverage Status

coverage: 93.791% (-0.1%) from 93.912%
when pulling de1add0 on LukasLendvorsky:disable_brs
into 811e2eb on OpenCyphal:master.

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Well done! Could you please bump the minor version and drop a line in the changelog? You will find details in CONTRIBUTING.md I will merge it right away.

Out of curiosity, did you code this by hand or was it done by a language model?

When running in CAN-FD mode, but with same nominal and data baudrate, BRS bit has to remain at zero. That indicates that there is no bitrate switch happening for data and data is transmitted at same speed.
@LukasLendvorsky
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LukasLendvorsky commented Dec 22, 2025

Well done! Could you please bump the minor version and drop a line in the changelog? You will find details in CONTRIBUTING.md I will merge it right away.

Done.

Out of curiosity, did you code this by hand or was it done by a language model?

I'm using some language models in my workflow, but in this particular instance it was done by me. There really is not much coding going on in this case and it seems easier to write few lines than try to explain what you want to language model.
Out my curiosity, is there particular reason why you are asking?

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Sorry, it is important that we bump the minor version as I mentioned and not the patch version. The minor version ought to be incremented for new features. Can you please update that?

Out my curiosity, is there particular reason why you are asking?

While reading the code it felt like it was done by an LLM, so I decided to ask ;)

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Sorry, it is important that we bump the minor version as I mentioned and not the patch version. The minor version ought to be incremented for new features. Can you please update that?

Done,

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3 participants