Hi Flo!
some IDs have an EFF flag set, some not. i dont know what that is yet.
Extended frames use more bits for the address (iirc 11 bit vs 29 bit).
- would i read ANY (wrong/different) data if i get the bitrate setting part wrong?
I have no experience with that but I'd guess not as CAN has checksums for messages to detect errors during transmission. This would make receiving "random" messages due to a wrong bitrate very unlikely.
- is there a reliable way to find out the correct bitrate used in the blackbox system?
Using a scope is definitely one way I did it before (by measuring the bit timings. Some scopes can even detect the bitrate and decode the CAN packets on the fly).
- any recommendations for FOSS software (linux) ?
I'm using SavvyCAN. It's a bit clumsy to use and unstable at times but it's a very powerful piece of software. I couldn't answer all your questions but I hope I could help a bit :P LG Jakob