Debugging ECU-response dependent UI flows

[Mattwmaster58]

This was mentioned in #79, but really should have a seperate tracking issue IMHO.

Is there a way to debug this without having to be connected to the car? I am interested in fixing this but not if I have to be tethered to the car.

@jglim response:

I don't think there's a quick and easy way to do that; if I remember correctly, I hacked up some j2534 library to sufficiently respond like a target ECU when I had to test stuff out, just the basics like session requests, testerpresent, identification.

If you go for this route, you'll probably want to pick your preferred language to build the emulation DLL. From my experience, .net (via DllExport : https://github.com/3F/DllExport) is alright to work with and I think works okay with Diogenes, but Vediamo does not like that and will crash. Vediamo prefers a regular MSVC DLL. Rust looks promising too but I'm not experienced enough to comment more about that.

And my response to that:

I think that there could be some value in just a simple record/replay framework. Going way lower level hopefully wouldn't be necessary? Just for the level of eg trying to load up the variant coding in eg #79. I will prototype it if I have the time, some time

[jglim]

Adding to my response, I also chose to do it at the J2534 level because it's a decent abstraction layer that's common to Vediamo/Monaco, and it is easy to capture high quality logs. It is indeed rather raw, though the low level aspect has been useful on a few for when troubleshooting connectivity issues on Diogenes.

Also, with a common abstraction layer, it's possible to sufficiently emulate a target that Vediamo can tolerate and then use it with Diogenes to check for implementation issues.

I like the concept of a record/replay framework although I can already see it running into issues where basic logic is required such as keeping track of the current session level. Not to dampen your enthusiasm, which I appreciate very much

On my wishlist, I would definitely love to have an easy-to-use j2534 emulation library in something like Rust, something with few dependencies and is easy for anyone to pick up and hack on, that will still work in Vediamo.