Thread: OBD1, and obdsim plugins

You know about this thread, right? http://www.mp3car.com/vbulletin/fusi...ram-linux.html

cgalpin: ALDL is a mid 80's to early 90's protcol that a good number of GM vehicles used. The reader for it is about $80, and most vehicles support a very large range of information being broadcast back at a rather insane data rate. Mine sends 70 values (a 70 byte string) 10 times per second.

Be careful when hooking in the FB to read analog voltages, as reading voltage can change the voltage that the ECU reads. I'm not entirely sure on the logistics of that.

Upon talking to an EE sitting next to me, he said that most microcontroller analog inputs are so high impedance to make it a non issue and you won't get any voltage drop. Perhaps 2k1toaster could pop by and confirm that the PIC chip the fb uses is high impedance on the analog inputs?

Bugbyte: no, hadn't found that thread yet. I first discovered there was such a thing as fusion brain about half an hour ago. Perhaps tripzero could throw in his 0.2 if he lurks on this forum still?

malcolm: Diffs are always welcome - especially from you, who unwittingly wrote a large part of the code in obdsim already [although that amount as a percentage is decreasing rapidly!] :-)

Also, malcolm, I had to make some changes to make the code run on OSX and on OpenSolaris - the OSX changes are in my repo already [eg, using posix_openpt(3) instead of hardcoding the linux on-filesystem equivalent], the OpenSolaris ones need a bit more testing before I'm going to commit them. You might find some of these changes useful to feed back into your own sim. [I ripped out windows support, though, since for now I have neither the urge nor the capability to support it - if anyone contributes patches for windows for obdsim, I'd definitely welcome them]

The manpages for pts(4) and pty(7) also make good reading. I think you need to use grantpt(3) and unlockpt(3) in your sim to be properly safe.

Gary (-;

Oh, and by the way; the current plugin API is limited in that you can only have one data generator plugged in at a time, changed at compile-time. I have the pattern worked out in my head to make all generators available in the same binary, but it will be a couple of [small] API changes.

If anyone actually writes code in the time between now and then [probably a couple days], then some extra fluff will be necessary to make it fit. I'm keeping the current set of functions prototypes in datasource.c, though, so the change will be very easy.

Gary (-;

The dbus - fusion brain thing is done, by the way, as is the ability to have multiple plugins all compiled in at once.

I mentioned it on the fusion brain forum here: http://www.mp3car.com/vbulletin/fusi...ion-brain.html

Have fun,
Gary (-;