Vida CEM swapping

[askrobek]

Try a few times and collect the logs. Don't need to go after position 3, just reset and start over. Post logs here.

120 Ohm resistor better be out for the in-car cracking. Also you need a good power to the board.

Thanks, I will try to repeat a few times. But I'm not sure if I'm able to desolder these tiny resistors with my skills and equipment. Thanks for all the suggestions though.

I recorded 2 videos of what was going on.

[askrobek]

Pin 3 : CANLS-H
Pin 11: CANLS-L

Pin 6 : CANHS-H
Pin 14 : CANHS-L

Pin 4 : Chassis ground.
Pin 5 : Signal ground.

Remember when you flip it over the pin orders reverse.

Run you hand across the bottom of the board. Are any of the rails pushing out?

Thanks. The plug actually has numbers next to pins, so I'm using them as a reference.

[RickHaleParker]

Thanks. The plug actually has numbers next to pins, so I'm using them as a reference.

Just keep in mind when you flip a part over the pin order inverts. That gets a lot of people.

[askrobek]

Try a few times and collect the logs. Don't need to go after position 3, just reset and start over. Post logs here.

Here is the log from attempt #2 (lost the log from attempt #1). Also failed. Will give it yet another try.

[vtl]

First two bytes are clearly 03 55. Third byte in your CEM is hard to crack (there was a theory why some CEMs have problems with the third bytes, lost somewhere in this rather long thread), but if you set CALC_BYTES to 2 and leave it overnight on a battery charger, you'll get it brute forced in under 18 hours (max wait time, usually much less).

Or you can work on a better hw implementation, it is chasing for the ~hundred nanoseconds jitter.

Sometimes it helps to run at full 600 MHz speed, remove "set_arm_clock (180000000);" line: https://github.com/vtl/volvo-cem-cracke ... .ino#L1002

[RickHaleParker]

Well S**T! I don't know for sure my board is going to come populated.

"If you want to assembly parts, before enable the SMT option, you need to check all your parts are using “LCSC Assembled” class libs, and then upload the BOM file and Pick and Place file. "

All my parts are library class LCSC except the J1962 connector. There is no “LCSC Assembled” class as instructed above. There is a "JLCPCB Assembled" class but no "LCSC Assembled” class.

EasyEDA documentation sucks! Nothing easy about it. EasyEDA has the potential to be easy but that gets destroyed by the crappy error riddled documentation.

Had a chat with JLCPCB. EasyEDA, LCSC parts and JLCPCB are three separate companies that do not cooperate. JLCPCB will assembly from their inventory only, which is rather limited. Not one of the parts I used are in the JLCPCB inventory. It does not look like I will be able to put together a one click design that JLCPCB can build and assembly.

If they are three separate companies what do their websites all have the same theme? Something is wrong with this fish.

[vtl]

If they are three separate companies what do their websites all have the same theme? Something is wrong with this fish.

You are picky It is still a miracle for me that I can launch a web browser (running in my not very popular OS choice), open a web site, do schematics, place&route, BOM and purchase a partially soldered PCB for cheap, delivered from China, end to end in under 2 weeks

In my younger years I used to draw PCB traces with nail lacquer and etch it in iron chloride.

[askrobek]

First two bytes are clearly 03 55. Third byte in your CEM is hard to crack (there was a theory why some CEMs have problems with the third bytes, lost somewhere in this rather long thread), but if you set CALC_BYTES to 2 and leave it overnight on a battery charger, you'll get it brute forced in under 18 hours (max wait time, usually much less).

Or you can work on a better hw implementation, it is chasing for the ~hundred nanoseconds jitter.

Sometimes it helps to run at full 600 MHz speed, remove "set_arm_clock (180000000);" line: https://github.com/vtl/volvo-cem-cracke ... .ino#L1002

Thanks. I also noticed that, when I was live-watching the cracking process for the first time. The diff in the latencies for the best 2 candidates for byte #3 were less profound and less consistent compared to the #1 & 2. It is also visible in the log previously attached that is from the 2nd attempt. I'm ran it for the 3rd time and again, the #3 looked problematic and did not crack. I guess I will try the overnight BF with a charger, this HW implementation is the best I can do right now. Thanks for all your comments, they are extremely helpful for an amateur like me.

[RickHaleParker]

You are picky It is still a miracle for me that I can launch a web browser (running in my not very popular OS choice), open a web site, do schematics, place&route, BOM and purchase a partially soldered PCB for cheap, delivered from China, end to end in under 2 weeks

In my younger years I used to draw PCB traces with nail lacquer and etch it in iron chloride.

Followed the instructions for ordering a assembled PCB. Looks like the only thing I will be getting are SMT stencils, no PCB. Beginning to wonder if I would be better off looking elsewhere for a EDA system. EasyEDA is too misleading. Documentation reads like it was outsourced to somebody that cannot stay focused. Jumps from topic to topic or to subject without any clear indicator that the topic or subject has changed.

Did you ever do wire wrap? I still have a electric wire wrap gun. That was a cool tool at one time. How about hammering nails in a board and wire wrapping. That is where the term Breadboard comes from. A Bread cutting board was the one piece of wood that was plentiful. Nails where plentiful and enamel covered wire was all over the place.

[vtl]

Did you ever do wire wrap? I still have a electric wire wrap gun. That was a cool tool at one time. How about hammering nails in a board and wire wrapping. That is where the term Breadboard comes from. A Bread cutting board was the one piece of wood that was plentiful. Nails where plentiful and enamel covered wire was all over the place.

I did. I became a certified electrician in high school (the school was outsourcing professional courses to other educational institutions), allowed to work with voltages up to 380 V freely and 1000 V under supervision. It was very old school: soldering DIP chips was at its max competence. Breadboard, nails - yes...