PC's and EFI

[Steven Gorkowski]

Put a sound board in the pc an run Visual Basic It has support for
record on the DSP on the sound board 8 or 16 bits . use game port for
A/D and I/O as well as par. port and place a A/D mux(4051,ect) on
printer port and get as many A/D channels as you need.

Steve

Raymond C Drouillard wrote:

> On Wed, 18 Mar 1998 01:23:15 -0600 "Terrie S. Watts"
>
> >Careful here.  I'm a pretty good programmer myself and I actually
> tried
> to
> >write a fuel injection (plus ignition control) on a 100 MHz Pentium
> laptop in
> >straight assembly code and still found by way of the O-scope that I
> wasn't
> >servicing multiple events quick enough.  It's much tougher than it
> would
> >first appear.  It can still be done but one needs to throw a little
> more
> >hardware at the problem to really get it working correctly.  The big
> problem
> >is that the CPU executes but a single instruction at a time and there
> is
> >quite a bit of things having to do with the engine all happening
> simultaneously.
> >I found myself in a priority battle trying to determine what
> absolutely
> has
> >to happen next and what could wait several clock cycles to get around
>
> to.
> >This strategy shows up on the scope and leads to quite a bit of head
> >scratching when the engine just doesn't seem to run up to snuff.
>
> I would be the last one to try to argue my theory against your
> experience.  I based my information on the fact that someone made a
> usable system with a 4.77 MHZ PC running BASIC.  Based on what you
> said,
> I suspect that he got away with it because he was running a TBI system
>
> with no spark control.  Also, a 386/25 is many times faster than a PC.
>
> The method I had in mind for controlling eight injecters wouldn't take
>
> much more processer time than running one.  The part of the program
> that
> controlls the would send a string of 1s and 0s to another routine that
>
> would send 00000000 to the parellel port when it receives a 0, and
> 00000001 or 00000010 or whatever (depending on which injecter is being
>
> fired) to the parellel port.
>
> How did you control the time sharing?  If necessary, some custome
> device
> drivers could be written.
>
> I saw some comments on using SCSI or IDE controllers.  That would
> certainly work. The approach I'm going with, howeverl, is the KIS
> (keep
> it simple) approach.  I want to use the devices that are designed to
> talk
> to something outside of the computer.  That saves some potential for
> hassle.
>
> If you want to control eight spark coils, for instance, you could have
>
> the computer send out a couple bytes of data through a serial or
> parellel
> port.  The computer would instruct the controller which plug to fire
> and
> when to fire it.  The computer could then go on to other things.
>
> The real trick is to not require the microprocessor to actually fire
> something at a specific time.  It should calculate when and how much,
> then load that data to something else.
>
> A sound card could easily create a waveform that'll fire an injecter.
> Just route it to the correct injecter (perhaps based on input from an
> RS232 port), and amplify it.  If you use a sound card with a
> programmable
> wave table, you can set up a variety of duty cycles and durations.
> That'll offload a lot of processing from the microprocesser.
>
> I don't know how much goofing around it would take to get the computer
> to
> read two game ports at once, but it shouldn't be too difficult.  It
> might
> just be a matter of assigning addresses for each one.  You'll need
> several analog inputs.  The output of the various sensors can be
> conditioned with op-amps and fed into the game port and sound card.
> This
> would give you a total of six analog inputs. You will need an input
> for
> the coolant temperature, the air intake charge temperature, MAP (or
> MAF),
> and TPS.  Digitan inputs would be some kind of knock sensor (sound or
> ionization) and crank position.
>
> Now you guys did it!  Got me thinking about a project that I don't
> really
> intend to undertake.  Sometimes, it's tough being a compulsive
> engineer.
>
> Ray Drouillard, BSEE
>
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