PC's and EFI

[Raymond C Drouillard]

That's an interesting diatribe - true, as far as I can tell.  I, too, am
experienced with PCs.  I'm writing this on a Cyrix 200 MMX with 64M of
static RAM, 2.5 gig HD, 24X CD, etc. that I put together myself.  I write
programs for a living.

The point that may have been missed is that you don't need even a 486 to
run a fuel injection system.  I have a 386/25 board in my basement that I
am going to give away, and a couple of 286 boards that I can't even give
away.  Any of those would be sufficient for the job.

If I needed another hobby and wanted to build my own controller, I would
probablly use a PC, since all the interrupts and memory handling and
stuff like that is already done.  You can control eight injecters with
the parellel port and a handful of transisters.  You can add a couple
more parellel ports if necessary, or use a couple of the handshake lines
on the serial ports.  The game port will provide for some variable
voltage inputs, such as the MAP sensor, the O2 sensor, the TPS, etc.  I
believe that you can get four analog inputs.  If you need more, get a
sound card.  If you want some digital inputs, the game port has a few of
those.  So far, I have discussed nothing that would require that you mess
with the ISA bus or actually modify the computer.  It would require a
minimal amount of electronic knowledge that can be learned from some of
the small "engineer's notebooks" that you find at Radio Shack.

As far as a moniter, you would only need that for the initial setup.  You
could get one of those $20.00 DC/AC inverters that they sell in the
Damark catalog and power up the moniter until you have it all tuned.

The software wouldn't necessarily be very big.  You could probablly load
it from floppies.  A couple of 1.2 or 1.44 floppies would make a good
backup if the board loses its power and you need to reload the program.

That's the dirt-cheap method.  Most of the stuff I mentioned could be
gotten for free or very cheaply.  If you want to spring for a used
laptop, you could use the same methods and the same program.  I bought a
486-50 for less than $400.00 and used it to program my Holley Pro-Jection
system.  I power it with its 110V power supply and an inverter that I got
from Damark.

The advantage of using a used laptop is that you can set up a display
that gives you the outputs of the sensors, the O2 correction, the
injecter volume, etc.  You could also store that data to the hard drive
for later analysis - much like the Holley Pro-Jection 4Di system does. 
Best of all, you could load the system on the laptop that you normally
use for business or whatever and have an emergency backup if the laptop
that runs the car ever dies.

I would probablly use MS DOS 6.22 as the operating system because there
is so much software available for it.  If you're using an old 386 or 486,
you can get the older software really cheap or free.  If you are using an
old motherboard and a couple of floppy drives, I would suggest an old C
for DOS compiler so that the resultant executable will be small.  If you
are using a laptop, go with whatever you're used to. 

Another option is to use Unix, or one of the shareware Unix work-alikes. 
That way, you don't need a moniter.  Just load the system and talk to it
with a laptop and an RS232 cable and nullmodem adapter.  That would make
the system quite similar to the Holley Pro-Jection 4Di system.

After you get the basic system working, you could start playing with
other stuff.  You could control your automatic transmission with it.  You
could put a pushbutton on your steering column that would lock up the
torque converter for compression braking, and program the computer to
release it if the engine is in danger of dieing.  You could make your own
antilock brakes.  If you have a 4WD vehicle, you could use the system to
slow down the spinning when one wheel of the four loses traction.  If
you're really a glutton for punishment and want to do some tricky
programming and testing, try to duplicate the skid control system that
one of the German auto manufactures developed.

Ray Drouillard, BSEE


On Tue, 17 Mar 1998 05:50:40 -0800 "Robert Harris"
<bob at bobthecomputerguy.com> writes:
>
>On to the subject of PC's in automobiles.  First, a small bonafide.  I
build
>about a dozen custom built PC's a week, and have built or repaired
literally
>thousands of them.  The care and feeding of PC's is my second line -
>primarily Aerospace Software Weenie.  I have more than a clue about them
and
>an extensive enough hardware and software background to understand them.
>
>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
>"Industrial" catalogs - which feature ancient crap at excessively
ridiculous
>prices - like two hundred dollars for a three year out of production
video
>card that was originally available Chinese at 20 bucks.  In fact, unless
you
>have good Chinese sources maybe you ought not even consider a PC because
>believe me - you are or will be raped. The Computer Shopper, PC Magazine
or
>whatever prices are bending you over.  No good sources - don't bother. 
And
>after having seen most of the crap being sold as "industrial", believe
me,
>it is mainly obsolete consumer stuff that someone couldn't dump. Buyers
and
>engineers are such easy marks. Only thing easier is to sell a black mega
>power system to a Lawyer or Doctor.
>
>Current reasonable prices - Pentium MMX motherboard - about 85 bucks -
Intel
>166 MMX about a 110. Fan about 5 - say two hundred bucks and falling for
an
>excellent motherboard.  With on board IDE, PCI, Floppy, Serial,
Parallel,
>PS-2 mouse, IR, and USB, flash BIOS and 512K on board cache.  Size -
baby
>AT. 32 Meg ram - about 70 bucks or less.  2 gigabyte hard drive - just
over
>$100.  Yada Yada Yada CHEEEP  CHEEEEPER  CHEEEEEPER YET.  The negative
>voltage's needed current draws are small enough to build a dozen power
>supplies and use the commercial stuff and still save mega bucks.
>
>Your problem is VIDEO.  If you plan to use any off the shelf software,
you
>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
>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.
>
>Software choices are DOS - ancient history and mainly the reserve of the
>cantankerous (and no bull crap about excellence or adequacy or whatever
-
>DOS and Windows 3.x are as dead as CPM - join reality), Windows 95 or
Linux
>(do yourself a favor - do EFI_332 if this is your choice).
>
>The option of writing your own operating system exists ONLY if you do
not
>want ANY commercial software to run on it. A compromise if you plan on
no
>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.
>
>If you are writing your own and you get this gleam in your eye about the
>bios - reality check. The BIOS is written for specific chips on the
mother
>board and they are all different and extremely hardware dependent.  If
you
>got years of time and documentation that generally is not available to
the
>public (do you buy 50,000 chipsets ? no - forget it not worth the chip
>makers time to provide you the documentation - plus a lot of it is
covered
>by trade secret/copyright protected or at least a major bond and
>non-disclosure) you might write your own before the 5 year life
expectancy
>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.
>
>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
>it go into the power save (notebook give you a clue?) mode and live with
the
>milliamp drain to keep it alive.  Any interrupt can trigger it back
alive.
>
>And storage devices - another phony baloney.  Almost all aircraft
computers
>run with program in ram - reloaded only when updating.  With more ram
than
>you can imagine cheap, just leave it in ram and boot/reboot from a
floppy -
>or better yet a 120 meg IDE LS-120 removable hard drive. All hard drives
are
>rather rugged compared to 5 years ago - but for 40 bucks, you can get a
kit
>that makes is almost vibration proof.  But, then be a good dweeb - pass
on
>it and spend a thousand bucks for a "RAM DISK" or some other 
>industrial nonsense.
>
>I could go on for days about this, but don't bother.  The only practical
way
>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
>already has a supported display, it already is ruggedized and vibration
>resistant and you can use some of the ports to interface to whatever. 
It
>even gives you a chance of having it working before the asteroid
arrives.
>
>Keep in mind that a Pentium 166 (which ain't even heavy duty any more)
is
>several thousand times faster and more powerful than a 4.77 MHz PC.  In
>fact, it is more powerful than any early eighties supermini computer and
far
>more powerful than the seventies supercomputers. Along with this power
comes
>a lot of complexity and massive overkill.
>
>All of the above is why I am considering stamps and pics to build my own
>system - in small, doable modules.  I prefer to de-complicate
defecation.
>But what the heck do I know anyway.

_____________________________________________________________________
You don't need to buy Internet access to use free Internet e-mail.
Get completely free e-mail from Juno at http://www.juno.com
Or call Juno at (800) 654-JUNO [654-5866]