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Read CAN Bus with Microcontroller

 
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muellet2
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Free account, no CAN development support

Post30-10-2006, 9:19    Subject: Read CAN Bus with Microcontroller Quote

Hello everyone,

I just finished building a microcontroller that reads messages from the CAN bus. To test this device on my Golf, I need your help.

The CAN bus is not exposed at the diagnostic connector, which is why I wanted to connect the CAN drive and CAN display directly to the connector. Does anyone know where the shortest distance to the next wiring harness is, and what colors the CAN High/Low wires have? It might even be better to orient myself based on certain pins on the main control unit (SG), as I might misinterpret the colors otherwise.

Furthermore, I don't really believe it .
Greetings,
Toby.


Translated on 01-08-2026, 13:15.
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Rudi
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Free account, no CAN development support

Post30-10-2006, 10:44    Subject: Read CAN Bus with Microcontroller Quote

If you had mentioned what kind of car it is ('Golf' is a bit vague), someone might have been able to help you.
There are no internal manufacturer documents available!

Rudi.


Translated on 01-08-2026, 13:17.
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muellet2
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Free account, no CAN development support

Post30-10-2006, 14:28    Subject: Read CAN Bus with Microcontroller Quote

Hi,

I'm sorry - I was in a hurry this morning. Of course, things are constantly changing. So, I have a 1.9 TDI engine, with the code ASZ, produced in September 2002, and first registered in October 2002. The model variant is 'SPECIAL'.

Thank you in advance!
Toby.


Translated on 01-08-2026, 13:18.
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Rudi
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Free account, no CAN development support

Post30-10-2006, 15:07    Subject: Read CAN Bus with Microcontroller Quote

CAN H: or/sw
CAN L: or/br

Best regards,
Rudi


Translated on 01-08-2026, 13:18.
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wuzel80
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Free account, no CAN development support

Post30-10-2006, 18:50    Subject: Read CAN Bus with Microcontroller Quote

You could let me know what information you can read out from your microcontroller and how much everything cost!


Translated on 01-08-2026, 13:19.
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muellet2
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Free account, no CAN development support

Post30-10-2006, 20:46    Subject: Read CAN Bus with Microcontroller Quote

I'll briefly describe the project once I've made more progress, but without information about the CAN matrix, things look bleak.

Thank you for the pinout information!

Best regards,
Toby.


Translated on 01-08-2026, 13:19.
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Jochen_145
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Free account, no CAN development support

Post30-10-2006, 22:51    Subject: Read CAN Bus with Microcontroller Quote

I will briefly describe the project when I have made more progress, but without information about the CAN matrix, it looks bleak...

Best regards,
Toby.

Yes, it seems things will likely remain bleak. This information isn't being 'traded' in the context of online fraud.
Wenn du jedoch eine Adresse im Netz findest, wo diese Infos liegen, wäre ich über Infos sehr dankbar. GPlease also send it to me as a private message (PM).

That would make many things easier for me.

I would tap into the CAN bus located on the instrument cluster (IC), as that's where the comfort and powertrain CAN buses are. In the case of a Golf IV, it might also be possible to access the CAN bus through the OBD port, since this port doesn't use CAN for diagnostics.

Regards,

P.S.: Reverse engineering works if you can already see the raw CAN values, but it's not a worthwhile endeavor icon_sad.gif.


Translated on 01-08-2026, 13:21.
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muellet2
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Free account, no CAN development support

Post30-10-2006, 23:18    Subject: Read CAN Bus with Microcontroller Quote

Without a solid data foundation, even a 'reverse engineer' is just groping around in the dark. You might be able to read the messages, or frames, but without any clues about the possible 8 bytes of data, and how they are structured and scaled, it's all useless. Someone really needs to be directly connected to the source.

Let's see, maybe something will turn out after all... Maybe an applicant will have some sympathy for us icon_smile.gif.
Best regards,
Toby.


Translated on 01-08-2026, 13:23.
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muellet2
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Free account, no CAN development support

Post10-11-2006, 2:57    Subject: Project Completed: Success! Quote

Hello again,

The device is now complete. The following options are available:

- Display of 4 lines for 4 different signals from the CAN messages.
Signals can be freely read according to the standard CAN format, with options for signed/unsigned representation and lengths from 1 to 16 bits.
- The indicator display is configured via UART from a PC.
- Up to 1 Mbit/s!!
- CAN_TX, so that sending also works, but since I don't have a 'test vehicle,' I could only test this function on the computer so far. Once I finally have some concrete information, we can start working with the actual vehicle.
- If I've forgotten anything that seems obvious, please feel free to ask. Otherwise, here are the costs:
Hardware: approximately €55.

Greetings,
Toby.


Translated on 01-08-2026, 13:25.
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Ross-Tech-Support
Profi-Schrauber
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Joined: 05/30/2005
Posts: 646
Karma: +8 / -0   Thank you, like it!


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Post10-11-2006, 3:56    Subject: Read CAN Bus with Microcontroller Quote

Besides the fact that similar offers already exist in several variations, I don't think these kinds of posts are welcome here. Perhaps you should have discussed your sales intentions with the forum administrator beforehand.


Translated on 01-08-2026, 13:26.
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Georg_G
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Joined: 04/12/2002
Posts: 332
Karma: +6 / -0   Thank you, like it!
Location: Freiburg im Breisgau
2012 Volkswagen Golf
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Post10-11-2006, 13:19    Subject: Read CAN Bus with Microcontroller Quote

Quote:
Besides the fact that something similar already exists in several variations, I don't think that offers like this are welcome here. Perhaps you should have discussed your sales intentions with the forum administrator beforehand...




Just a side note:

I can't see from muellet2's posts that he is trying to sell his device here.
Perhaps one shouldn't blindly follow the forum administrator's instructions and seize every opportunity to admonish other people!

No offense.

George.
Golf VI Variant (2012) 140 tkm, CFHC Schummeldiesel


Translated on 01-08-2026, 13:27.
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