Old 486 Board for ECU? Why?

Thu May 4 00:12:07 GMT 2000

> This topic sure seems to be using alot of bandwidth!

Isn't that good?  means people are thinking and stimulated.

> 1) A pc old motherboard
> 2) an ISA card for IO, ADC's, current drivers, etc
> 3) another card ( or maybe physically part of the ISA) to

Yes, but that's good.  If you build a PC based system, if the
motherboard blows for whatever reason, and your ISA card is what does
some of the work, toss system board, buy new one for $79.95, and reboot
:)

The more customized you make it, in general, the more of a pain in the
ass it is to replace things when they break.  I am not an embedded
engineer nor a programmer (I can make almost anything say "Hello World",
but that's about it), so I might be off base here.  But for me,
considering I am in the PC/Network/SErver/Infrastructure business, there
are always nearly free or completely free systemboards I can shove into
this.  Free replacement parts is good.  My custom card however, will be
a nightmare to fix, repair, or replace.  One off's are very expensive. 
I must have spent close to 100 hours soldering surface mount parts by
hand.  I would not recommend it.  I soldered using a rat-shack soldering
iron with a copper tip that I hand filed to a nearly razor knife edge to
do this, and made simply aluminum "chip clamps" to prevent heat damage
to parts.  Getting these little parts to hold still was a pain, while
soldering.  I used glue :)

> happy in the auto electric environment (i.e not reset every time junior
> flips the power door locks)

If you build a switching power supply, you can make the output fairly
irrelevant to the input.  The power supply my friend made for me takes
9-20V in, case being ground, and switches that into +/-5, +/-12.  I'm
waiting for delivery on this, haven't tested it.  Since I've been dyno
testing where the dyno is stationary, I've been using a PC power supply
with a 50' extension cord :)

> Now you put it in a case the size of a small briefcase and try to ruggedize it.
> (you could go the industrial route but the costs gets out of hand quick)

No kidding.  I intend to braze together an aluminum box out of 1/8"
aluminum with standoffs inside, since I have it.  Plus the power supply
board.

> The motherboard just wasn't designed as an engine controller.  (It would make
> a good teller machine controller however)

Chase and Citi do this.  Big time.  Run NT too.

> purpose programmer for the most common and powerful GM ecm.  Sort of like
> the SY/Ty editor but for something more common than the 749 ecm.

Because Java is interpreted, and inherantly slower than machine code. 
Unfortunately, because anything that works cross platform is a good
thing. Scale up and down as necessary.

> specify number of cylinders, dis or hei ignition,turbo or non, map or maf
> etc.  Something pretty generic.

My card supports 32 injectors, two TBI sensors, one MAP or MAP sensor,
eight O2 sensors, a crank and a cam sensor (electromotive stuff, not OEM
stuff), and a variety of other stuff.  Its generic enough that in
theory, you could have 4 injectors per cylinder (or not) of different
fuels, use OEM injectors with small flow on huge-ass turbocharged
engines (which is what I'm doing), and of course, a variety of inputs as
well.  I haven't written the software yet, so don't hold your breath. 
FOr me, this is nothing more than an expensive idea that uses a spare
486 system board.

> I realize someone would have to know HC11 code well to do this, but it would

HC11 code is not that difficult.  I purchased a HC11 trainer board used
a few years back, then a friend of mine gave me a HC332 trainer board. 
While this in itself is not an EFI computer, its the foundation for
building one.  Its pretty easy to learn code writing on the trainer.  C
is C.  The C for HCxxx is drastically simpler, but that's good, its
easier to learn.  The most difficult problem that plagued me was booting
code without the trainer board with the funky watchdog software.

> At the end, we would have code of our own design on a ecm unit designed to be
> a ecm, not a rigged up pc.

yes, however, using the PC, you can have it do other things.  Or not. 
There are many advantages/disadvantages to this, and I'm not going to
harp on them because I could very easily start a heated discussion on
this, as a lot of us have different opinions, which is actually pretty
cool.  This is nothing more, than one way to tackle the problem.

-- 

Frederic Breitwieser
Xephic Technology
769 Sylvan Ave #9
Bridgeport CT 06606

Tele: (203) 372-2707
 Fax: (603) 372-1147
Web: http://xephic.dynip.com/
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