Vida CEM swapping

Post by **vtl** » 22 Feb 2021, 07:15

jcdillin wrote: 22 Feb 2021, 07:05 Do you need something like this to talk to it serially?

https://www.nxp.com/products/interfaces ... ce:MC33660

Or just toggle it?

Uhhh... Didn't think about it. If the protocol allows for a unidirectional talk, the toggle is fine. I don't know, sorry. Maybe a guy smarter than me could answer your question.

Post by **RickHaleParker** » 22 Feb 2021, 09:00

vtl wrote: 22 Feb 2021, 07:15
jcdillin wrote: 22 Feb 2021, 07:05 Do you need something like this to talk to it serially?

https://www.nxp.com/products/interfaces ... ce:MC33660

Or just toggle it?
Uhhh... Didn't think about it. If the protocol allows for a unidirectional talk, the toggle is fine. I don't know, sorry. Maybe a guy smarter than me could answer your question.

Until somebody adds support for K-line. Supported vehicles in the readme needs a revision. The K-line P2s are includes in the current readme. P2s before 2005 are K-line not CAN BUS.

P2: (CAN BUS only).
2005 - 2006 S80
2005 - 2007 V70
2005 - 2007 XC70
2005 - 2009 S60
2005 - 2014 XC90

jcdillin · Post by **jcdillin** » 22 Feb 2021, 09:09

Ok, I'll work on adding that to the schematic.

Post by **RickHaleParker** » 22 Feb 2021, 09:21

Teensy 3 K-line library on Github. The coders here might be able to extract some useful information from it.

Post by **vtl** » 22 Feb 2021, 09:50

All P2s have CAN-bus, it just needs to be opened via K-Line. See a link to Olaf's blog on page 25.

Post by **RickHaleParker** » 22 Feb 2021, 10:29

vtl wrote: 22 Feb 2021, 09:50 All P2s have CAN-bus, it just needs to be opened via K-Line. See a link to Olaf's blog on page 25.

And a resend every 5 seconds or less to "keep-alive" otherwise it closes.

Olaf wrote: I managed to find this conversation, containing advises to send a certain "keep-alive" message every 5 seconds to K-line (pin 7 on OBD-connector) to keep CAN bus interface open. Content is "84 40 13 B2 F0 03 7C", serial settings: 10800 baud, 8N1 and voltage range 0-12V (0V=0b, 12V=1b).

Post by **vtl** » 22 Feb 2021, 10:38

RickHaleParker wrote: 22 Feb 2021, 10:29 And a resend every 5 seconds or less to "keep-alive" otherwise it closes.

Yeah, not a big deal at all.

Post by **RickHaleParker** » 22 Feb 2021, 10:46

vtl wrote: 22 Feb 2021, 10:38 Yeah, not a big deal at all.

I know, my electronics back ground is hardware. In electronics 5 seconds is an eternity.

Post by **gnalan** » 22 Feb 2021, 11:28

I'm still wondering why nobody is using DiCE to connect to the OBDII instead of trying to special build something else to do what It's already designed to do, which is to read/write to Volvo cars.

My authentic Volvo DiCE unit uses the above ARM Cortex-M7. I'm still reading through the instruction set, since I'm not familiar with ARM or Thumb, but it doesn't look too complicated to work with.

Post by **RickHaleParker** » 22 Feb 2021, 13:30

gnalan wrote: 22 Feb 2021, 11:28 I'm still wondering why nobody is using DiCE to connect to the OBDII instead of trying to special build something else to do what It's already designed to do, which is to read/write to Volvo cars.

You figure out how to measure the response times with a DiCE and pass on the information. I'm sure somebody here could take the information and write an application to crack the pin.