Software On ELM Street - OBD2 Software Development

[Tazzi]

Ahhh Good to see the tool actually worked and picked up responses! Cheers for testing VX and Jayme!
Wouldnt worry about the VIN section yet.. havent fully coded that one in!.. Wasnt sure what to expect back!
As for the -39 degrees, thats just the conversion that the "generic" response needs. Its not actually -39 lol, just because its on bench.

Im hoping to make this tool a bit more specific for Holdens. It will have same generic stuff, but Id like to figure out the Holden specific PIDs and also holden specific fault codes.
I *think* iv sussed out how to mimic a pcm to the tech2, If I enable the ATMA to monitor all chatter, filter through the chatter for the tech2 request, then send through a "false" pcm answer. So will need to set the header up correctly and also turn off the elm response (ATR0), then revert back to monitoring the chatter.
Hopefully the elm is quick enough to keep up!

So if the software is actually working then and getting responses.. then Ill try add some more stuff this arvo. Good to hear that the elm does actual use a carriage return at the end! Makes it alot simpler! If I get my cable working when it rocks up, then ill just use that as the recommended cable to work with the software that way everyone has the same stuff.

Anything In particular anyone wants added?
Ill be applying the "monitor all" function including the filter functions so that may be useful for anyone wanting to watch specific traffic. And will see if I can get the vin function working as well.
Then itll be attacking the tech2 for the specific codes. Let me know if anyones interested in helping reverse the tech2/scantool specific codes, will need to have the scantool and elm cable connected up without a pcm connected.

[Tazzi]

Attached is v0.10.
Added the monitor all function as said before, will be under the custom frames section, It will just keep displaying whatever is on the bus until it is ended, or timesout.
The custom send/receive should work as well.

Annnnnd, the vin section *MAY* work.. I had another crack at what would be received, it picked up the echo last time as seem from Jayme's testing.. which it shouldnt have so made sure it wont do that this time.

Started on the fake pcm app this arvo, its semi working using the elm simulator. If a few of us map out the pids that scantools pops out, should be able to smash out all of them pretty quick.

Does anyone know where the "manufacture specific" PID are? is there a specific range for them? or are they just in random places?
Same with the fault codes, from what I can see theres a couple ways of requesting fault codes. Such as $19,$XX,$FF,$00. Where XX requests specific faults. Or the other method is just $03
Guess there not much use unless we have the scantool to reverse what they mean anyways!

[Charlescrown]

Boy been away for a few days but like whats unfolding. As I said before I have a commercial program that might help with the pids. I just need a car to plug into but that's nil at the moment.

[VX L67 Getrag]

I have a feeling the Monitor All command won't work unless the command for whatever is happening was by that device, so the port monitor program may be the only option to monitor other things happening if it uses a different device (if that makes sense).

I think I tried doing this a month ago with another paid software & the elm didn't see anything on it's port as it wasn't actually being accessed, but just a suspicion!

[delcowizzid]

i tried connecting to 2 vt's over the weekend with version 9 couldnt even detect cable when plugged in and was away from wifi access to try any other versions time was also limited.ive fixed the missing wheel on my mates test car so it can maybe get dropped off for a week of testing

[Tazzi]

i tried connecting to 2 vt's over the weekend with version 9 couldnt even detect cable when plugged in and was away from wifi access to try any other versions time was also limited.ive fixed the missing wheel on my mates test car so it can maybe get dropped off for a week of testing

Yeah? Man Im getting confused on why its not working! You had it working on the bench setup before, well the cable connection that is.

Could be the cable isnt getting a solid connection?? Hence isnt powered up correctly?

[delcowizzid]

I am wondering if i have one of the cables with a resistor accross the data line and earth like talked about online and its getting echo lol ill dig into it further just been busy and car is a distance away

[Tazzi]

Oh yeah no rush.

Nah the echo shouldnt be a problem, our OBD2 app checks for an echo and ignores it. Iv implemented that for a "just in case" sort of thing.
Would need to check that the diagnostic port is getting volts through the correct pin/s and also the two main ground pins are fine. Would also need to test with ignition off and on to see if there isnt an issue.

[Tazzi]

Just a quick look at what vx logged when using the software... seems some commands dont work!

Code: Select all

Request: 27/09/2013 6:02:34 PM.24764 (+13.9464 seconds)

 30 31 30 43 0D                                    010C.           

Answer: 27/09/2013 6:02:34 PM.41964 (+0.1716 seconds)

 4E 4F 20 44 41 54 41 0D 0D 3E                     NO DATA..>

This shows that 010C (get revs) was sent and the elms device sent back "NO DATA". Meaning that the elm device didnt get a response back.. Might need to make it resend a few times possibly?

I did read something about the requested data in some cars are not "priority" thus the response may take longer, and the elm will time out before response is sent.
I think changing our timeout interval from the default 400ms to say 1000ms will be sufficient.
So will need to send ATST hh where hh is the timeout value x4ms. Then 1000ms timeout will be ATST250

I thought I read something about disabling the chatter somewhere.. might be for CAN though..

Will update shortly.

[VX L67 Getrag]

NO I would have got no data as it was just PCM on a bench I think, but not sure?