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There are always better ways.... I'm up to reverse engineer some CAN-BUS signals. Before I start, I'd like to discuss with guys who done this before and are willing to share their methodology.

I'm interested in Hardware and Software used to achieve the goals of identifying CAN signals.

Any one with experience?

Thanks!

PD: it would be nice to have the tag 'reverse engineer' on this site :-)

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The only guys I know that have done CAN-BUS things are in the industry and don't reverse engineer. They just read the design documents and implement what they need... –  Brian Knoblauch May 6 '13 at 19:19
    
@BrianKnoblauch are such documents available to buy for mayor OEMs? –  otmezger May 7 '13 at 8:56
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You can buy that kind of information, I think. Try etools.org. $5000 to join, $2500 for the info. –  Derecho Aug 17 '13 at 7:21
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1 Answer

up vote 5 down vote accepted

While this might be a great question for the reverse engineering site that's in beta, I'll give you my take.

Hardware Options

1) They make an ODB II <==> UART hardware interface, that will give you serial access to your CAN signals. You can effectively read and write signals to the bus.

2) There are boards like Freescale's SABRE Automotive Infotainment, which is a single board computer that has a CAN chip on-board. This board will run linux and is heavily supported by the community.

Software Options

1) I'll address the linux software. A mainstream option for linux and CAN is SocketCAN. SocketCAN uses the OS Network Stack for communicating with the CAN bus. This is attractive for several reasons, for me the fact that multiple user space applications can read/write to the bus (just like the TCP/IP protocol). I found the kernel documentation extremely helpful.

There is test software called cantest and candump that will show what's being picked up on the bus, your best chance for reverse engineering the signals is to play around with certain functions of the car and look for repeating signals, such as pressing the the hvac button (for example) and looking for repeating signals on the bus. Diagnostic codes should be googlable or present in the repair manual possibly so that's easy enough.

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Thank you very much @MDMoore313. This is exactly what I was hoping for. I'm going to check on the software you told me, maybe it will run also on mac. –  otmezger May 7 '13 at 8:58
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