CAN Logging/Hacking Mini Series

[Jack Bauer]

While asking people on various places to perfrom some i3 CAN logging it bacmae apparant that very few understood the concept or indeed the why. Therefore I have started making a 3 part series on the topic.

Part 1 : What is CAN logging and why do we do it.

Part 2 : How to use GVRET /SAVVYCAN to connect to a CAN bus and capture data.

Part 3 : Basic guide to CAN reverse engineering.

Part 1 is freely available. Parts 2 and 3 will be patrons only for a 6 month period.

[mikeselectricstuff]

Is that passive probe inductive or capacitive?

I was recently messing around with ways of passively tapping CAN. Simply wrapping some sticky alu. or copper foil tape round each wire for an inch or so gave a signal good enough to read via a scope probe for protocol decoding on a scope. This was on the bench - may be trickier in a noisy car environment

I was also messing around with my i-prober 520 current probe, the idea being that if you tap the magnetic field on a wire going into a particular module, you only see the data which that module is transmitting, due to the current it's sending through the CANbus termination. This could help figure out which CAN IDs are related to that module.
This did just about work, probably not clean enough to do serious logging but easily good enough identify which CAN IDs were being sent by a module. I did have a brief play with GMR sensors and transformers to get a solution cheaper than the i-prober but couldn't readily get anything sensitive enough.
I'll probably do a video on this at some point.

[Jack Bauer]

I'm guessing its capacitive. Sounds like your doing some interesting stuff:)