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Comment by nvme0n1p1 | Hacker News Reader

> I was just looking at a small open source utility. As I was going through the code I found cases where certain arguments could be set to magic values that cause useful, but undocumented behavior. Should the developers be forced to document these options?

You were able to do that because it was open source. If a car mfr was willing to do that, it would be plenty enough for me. They shouldn't be forced to do any additional work beyond the 5 seconds it takes to type `git remote add origin github.com/honda/civic`. Then the community would have everything it needs to carry things forward.

Failing that, yes, I do think everything should be documented.

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I can poke at OBD and try to interpret values. CAN bus sniffers exist.

You want to force companies to publish and maintain repositories using your preferred toolset?

GP's point was not that manufacturers must use github - that was an arbitrary "for instance". They saying if the mfg is not going to open source their software, then they should be required to document it.

Certain PID values are bit-packed in non-obvious ways (like the tens digit is in one byte, ones in another, decimal in another) and units of measure are 'known' but might not be obvious. Publishing that information (which already exists! How do you think they write software?) would be a nice step in the right direction

J1939 is really all most consumers need to care about when it comes to their personal car CAN data.

https://github.com/Konik-ai/j1939_dbc/blob/main/dbc/j1939.db...

There are a ton of dbc files floating around like this. Almost any car with a turbo has a kit to flash the ecu for more boost, so even the proprietary signals have been reversed.

That's just BCD, which these days is transparent with AI.

> I can poke at OBD and try to interpret values. CAN bus sniffers exist.

Ghidra exists. That doesn't mean all software is open source.

> You want to force companies to publish and maintain repositories using your preferred toolset?

Nope. Anywhere will do, whatever is easiest for them, as long as device owners can access it.

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