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I'm looking for the protocol/guide to read the data from the CAN bus, but couldn't find on any (German) fora. Feedback/Answers are much appreciated.

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    Is your question regarding reading a CAN bus in general, or the specifics of the implementations Bosh Gen 2 electric motor (what registers contain what data, etc)?
    – CSM
    Commented Mar 27, 2022 at 13:35
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    Could be that Bosch doesn't want you to read those data! Industrial secrets.
    – Carel
    Commented Mar 27, 2022 at 14:26

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There are many flavors of CAN communication. Each flavor has its own bitrate and code length. Getting around security is the biggest problem you’ll encounter. The protocol loosely is as followed: You send a request to the target device, the target sends a “seed”, a numeric code in hexadecimal, your system has to respond with a numeric “key”. If correct, you’re in. Depending on the protocol, these seed/key combinations have different lengths. You would need the algorithm to compute the key from the seed. I worked for a automotive OEM, and these are closely held secrets.

I think the task without proprietary industry tools and CAN experience would be nearly impossible. Communication hardware is easy and inexpensive to find, the software and documentation is the difficult and expensive part.

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Once you get a CAN data logger you will have a lot of (binary) data that you will need to decode. The documentation on how to do that is often proprietary and not available.

However, as you're perhaps aware CAN buses are (also) used in the automotive industry. Maybe the efforts being made there to reverse engineer the raw CAN data can be of help to you as well? For example this repository hosts code that aids in "automated reverse engineering of Controller Area Network (CAN) payloads".

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