PC's and EFI

[Frederic Breitwieser]

Bob,

if (inconsiderate asshole = true)
then

source=fopen("//www.xephic.dynip.com/data/designs/toiletpaper/toiletpaper.ro
ll",read);
   des=fopen
("//www.bobthecomputerguy.com/inetpub/ftproot/uploads/toiletpaper.roll",
write);
   while not eof(source) {
       dblock=fgets(source);
       fputs(dest, dblock);
   }
   fclose(all);
   smile(Bob);
else smile(Bob, anyway);

>On to the subject of PC's in automobiles.  First, a small bonafide.  I build

Well, I do as well.  Been in the PC industry since 1985, currently serving
as a manager of Engineering and Design for a major NYC hospital - all the
PC standards, WAN connectivity, backbone upgrades, etc, stops on my desk.
PC's, routers, switches and hubs... that sorta thing.

>If money is not an object or being technically cute is - go for the PC-104 -
>I'm happy to let you pay ten times what I do for stuff.  Same for the

I can't argue your point about "industral" stuff - worked for places in the
past where everything had to be "industrial" quality - for the most part,
you are absolutely on the money.  The only issue that should be mentioned,
is the industrial PC suppliers do have a good variety of NEMA compliant
enclosures and keyboards - which to some degree, are acid, smoke, and
chemical resistant.  If you need this, great.  But the interior circuitry,
you are absolutely right, are the same quality as you buy from overseas.
No argument here.

I suggested PC104, for the simple reason that having a notebook PC fastened
to your air-bag equipped steering column with duct tape looks absolutely
ridiculous.  I can't argue about the pricing - a generic Pentium
systemboard for $85 is certainly a lot cheaper than a comparable PC104
setup - but the smaller form factor offers a lot of advantages.  In a
vehicle where space can be a premium, the 4"x6"x4" package with eight lines
of A/D, Stepper/Servo controlling, built in LCD controllers, sound,
mouse/keyboard, IDE/FLoppy/SRAM/Flash (etc, you get the idea), is a major
advantage over Baby AT, at 8"x12" plus almost 6" in height if you include
the upright cards.

I'm not saying your wrong - just trying to show why I suggested it in the
first place.

BTW, you mentioned how easy it would be to build a negative voltage power
supply in a vehicle, I've been searching for a schematic for a while now
and would appreciate one if you have it.  +/-5V +/-12V from 10-14V input
would be just about right.

>are going to need a display.  Now a CRT is cheap - about 160 for a 15" .28
>SVGA - but dah - it really sucks bouncing around on your seat.  So buy

I agree, see my comment about taping a notebook to your steering column :)

>yourself a nice DIY or Industrial flat panel at 5 times the price or more.
>If you DIY, you need to be a MSCD to write the device driver so the rest of
>your software can run it.

For a one-off situation, the surplus market is FULL of dirt-cheap displays.
 FOr example, a full VGA monochrome display can be bought for $25, and the
company (www.eio.com) has some documentation in PDF format for their
system.  $25 is not four times the price of a SVGA monitor, and if one is
careful in selecting their display, should be able to find one with the
standard 4-bit input method that all of the modern displays use - therefore
it plugs right into the PC104 system board.  Viola, instant display with
standard VGA capabilities for under a million bucks.

>Software choices are DOS - ancient history and mainly the reserve of the

While I agree that all of the above are goind downhill fast, running a
vehicle FI system on DOS is not all that impossible - and certainly EASY
for beginner programmers.  You stated your a programmer, so remember back
to when you started out - like all of us, you took baby steps, then
crawled, stood upright, walked, then ran to the level you are at now.  DOS
comes with BASIC, and on a faster machine, it would work.  Al Lipper, who
designed the PC-based system on the EFI website, used basic on a 4.77MHZ
XT, and it worked.

The only disadvantage of any embedded system that's custom made, for a
one-off production, is repair, replacement of parts, and things along that
nature.  I completely agree its a much slicker design (see your comment "I
prefer to de-complicate defecation".  Keeping it simple is technically the
BEST approach.  But, there is merit for a PC system - one can learn a
high-level language, reduce soldering and board design, and while its
significantly more expensive on a per-system basis on a techical sense, I
think having 20 bad designs of circuit boards silkscreened until you get it
right is also not exactly cheap.  We are comparing apples to tangerines
here anyway.  Each type of system has their merits.

>upgrades is to take DOS 6.22 and any device drivers, accept the fact that
>you probably will never be able to upgrade and live with it.

Depends what your strengths are.   If someone is making an EFI system, and
their strength and knowledge base is software, not electronics, the PC
system is an easy way to go - they could write their ECM code in visual
anything, or C using the freeware DJGPP compiler - whatever.  Not everyone
can design a 32-bit ECM utilizing Hitachi microcontrollers, AND have the
ability to produce the boards, solder them together, and make it work
within the first two or three tries.  You might be comfortable with it (as
am I), but not everyone has our experience.

>board and they are all different and extremely hardware dependent.  If you

That is true, however like everything else that runs on code - if you have
the knowledge, drive, and ability - you can change it.

>chips die.  And at 85 bucks for a good motherboard with everything working,
>I doubt that many are perverse enough to pursue this dead end - but have
>fun.

Been there, done that, obviously I'm happily perverse.

>And start up time - I really love this "Concern".  Do you think your ECU
>"starts" cold every time you turn the ignition on? Try disconnecting the
>battery and see what happens.  Boot the damn thing when you hook it up, let

Okay.  Disconnect the battery on your car.  Wait approximately 30 minutes,
then reconnect, and turn the key.  What happens Bob?  The car's starter
revs an extra rotation or two, then the engine turns over.  Its about as
instant as you can get.  This is the major advantage of purpose built
embedded electronics for ECM applications - its nearly instant during
powerup.  If you put your air-bag mounted duct-taped notebook in sleep mode
- it sleeps either on batteries (until they die) or by writing an image to
the disk (16MB?  32mb?).  Either way, it takes a few seconds for the system
to come back and stablize.

>I could go on for days about this, but don't bother.  The only practical way

That would be appreciated, considering the tone of your message.

>to run a PC in a car is a NOTEBOOK.  Any other package will cost you much
>more for much less. It already runs on 12 volts (option available), it

Well Bob, you made a very valid point - but its not a true embedded system.
 Where would you mount your notebook?  My air-bag mounting suggestion was a
joke, but seriously, where would you mount it so it looks like it belonged
there?  Cut a big hole in the center console?  How about replacing your
driver's visor and have the display flip down for viewing?  Maybe, have it
in the back seat, and require a passenger to give you feedback.  It depends
on your use - just ECM, or ECM and information center/digital dash?

>even gives you a chance of having it working before the asteroid arrives.

I drive a HWMMV, not concerned about no stinkin' asteroids <grin>.

>more powerful than the seventies supercomputers. Along with this power comes
>a lot of complexity and massive overkill.

Hey, to each their own.  I think both of us presented good arguments for
both sides, which I view as a good discussion.

>All of the above is why I am considering stamps and pics to build my own
>system - in small, doable modules.

And good luck with it.  :)


Frederic Breitwieser
Bridgeport, CT 06606

Homebrew Automotive Website:
http://www.xephic.dynip.com/

1993 Supercharged Lincoln Continental
1989 HMMWV
2000 Buick-Powered Mid-Engined Sports Car