I recently used a Windows program (on a laptop) in my car to acquire some data relating to engine knock, timing, and other things monitored by the car's control unit. It is a chore lugging a laptop around in the car. I was wondering if anyone has considered emulating the factory scan tools (OBDII?) with the empeg.

Edited by Mark Miller on 26/5/00 11:20 PM.

This sounds like a very interesting project. I had always assumed that those car computer interfaces were just a serial plug of some kind, so if that's true, all you'd need is a wiring adapter plug and the proper software.

Anyone have any information on what kind of software you'd need for this? Perhaps something that could be compiled under Linux?

___________
Tony Fabris

Most are just a serial port, but some have other analog signals as well. The older GM ports (c. 1986) also ran at a non-standard speed. We had to change the crystal on the old PC/XT serial boards to make it sync up.

There used to be a kid's radio story, "Sparkey and the Train" (or whatever) where a small boy hears the train telling him of a problem with the wheel on the carriage- it was whispering to him "right front wheel, right front wheel, right front wheel" in time to the chug of the locomotive.

I guess life is now imitating art.


Jon

Stan's not quite right there. Most modern (European anyway) cars use a protocol such as CANbus or Carline (VW/Audi/Seat/Skoda) which AREN'T the same as your old-fashioned serial protocol. If you want to communicate with any of them you will need a CANbus-to-serial converter, or similar. The cool thing is that then you will be able to communicate with all the microcontrollers in the car - motor control, ABS/ESP, instrument panel, air conditioning, sound system (at least in new Audis), security system, etc, etc! Would be quite cool to be able to collect and view this data on an empeg (especially as commercial (DOS!) software and the serial converter costs over 1400DM here in Germany) but if you mess up one of the controllers say good bye warrenty, and expect to pay LOTS for a replacement - the diagnosis software can also change the settings in the microcontrollers, which can make your car do some really strange things.

(list 6284, S/N 00299, 4 gig blue)

Mark, do you have any information, or a reference to a site that does, about which cars have what controllers and how to interface them? I've always been interested in that sort of thing for my Nissan NX but figured it was completely impossible (i.e. Nissan wouldn't tell me, nor anyone else).

Intensely curious!

<font face="lucida console">Save the whales. Feed the hungry. Free the mallocs.</font>

You are right, I should have said most USA data ports...

I have a Subaru Impreza Turbo (Jap Import) with an aftermarket programmable ECU! In addition I also have the serial link device which allows me to monitor/datalog ECU parameters such as knock, RPM, Wastegate %, Manifold air pressure (boost), etc. I have been toying with the idea of writing a console in VB for a CE machine so that I didn't have to lug my laptop around with me on a tuning session. It occurs to me that using the empeg which is obviously hooked into the car audio system makes perfect sense as I could get an audible warning of knock (engine destroyer)! Shouldn't be too hard as the serial feed is plain ascii.

Hmmm - that has me thinking.

M

what make is the after market ECU? I have a Subaru Forester which is based on the Imprezza and I have been looking for this sort of thing. could you give me some detail?

PeterH
" 'tis better to be silent and thought a fool than to speak and remove all doubt"

Peter,

The ECU is a PossumLink and comes with the appropriate harness interface so as it can be a complete replacement unit - it's even housed in the JECS ECU (std for Impreza) metal case behind the passenger kickplate. If your Forrester is an S Turbo, or other turbo variant then you might be in luck, the ECU may work for you. If not the I doubt it will be compatible. For more info I can highly recommend Bob Rawle(http://www.brdevelopments.com) He fitted and mapped my car originally (before I started tweaking) and is the most knowledgable person in the UK regarding these matters.

For other Subaru related matters you should visit the Scoobynet BBS and the 22b.com bbs's respectively (at http://bbs.scoobynet.co.uk/ and http://bbs.22b.com/) These lists are predominantly Impreza focused but there are other Forrester and Legacy owners using the BBS and getting help from people. The Subaru community is very much alive on the Internet. There are also mailing lists on egroups - the most technical one being the Impreza Web Owners Club ([email protected]), you can subscribe to the list by going to http://www.egroups.com/group/iwoc !

Happy Subaru owning and well done on your choice of vehicle! :)

Rgds,

M

The PossumLink Engine Management computer was developed jointly by Possum Bourne Motorsport and

LINK ELECTROSYSTEMS LTD:
243d Annex Rd, Sockburn, PO Box 9166, Christchurch, New Zealand. Fax +64 3 348-1595 ....Ph.+64 3 348-8854.

They should be able to give you more info about it.

(list 6284, S/N 00299, 4 gig blue)

I've been doing some work (with some friends) on creating an in-car HUD, running Linux of course. We've made some progress on talking to a '95 Camaro Z28, using 8192 baud serial ALDL. One of the secondary reasons I got an Empeg was to host such an application.
If anyone would like more information on what me and my buddies are doing - and remember, this is only good for ODBI, '95 Camaro Z28's, please let me know.

Dang

You can probably tweak the SA1100 serial driver to give you 8192bps - it has a master clock that runs at 2x what a PC serial will do (ie, max speed is 230,400bps).

Hugo