In addition to the mechanical low pressure fuel injection system
we are doing a PicAXE system. I am trying to find somebody to do
the actual work as I have a limited amount of time to do it myself.
I am talking to a couple of candidates as we speak.

This is a paradigm shift in EFI. One computer per injector instead of
many injectors per one computer. Each tiny computer is designed to do
one thing and one thing only. My rule is software complexity is

proportional

to the square of the number of features or things the computer must do.

PicAXE computers are super cheap. Spark plugs now use one coil per
plug with built in electronics. Why not one cheap, tiny, $1 computer per
injector. You can use two injector systems per rotor if you wish. These
systems will work with 1 to 4 rotor engines.

This is a cheap and simple PicAXE system written in easy to
learn and modify BASIC programming language. The PC sends
English language commands to the PicAXE and the PicAXE
does it.

A pulse is taken from the engine
crank  angle sensor and the computer measures the intake
manifold pressure or mass airflow sensor (A/D) and intake air
temperature and fires (PWM) one injector every time the one rotor
engine rotates once using a mixture look up table. A hardware
interrupt from the crank angle sensor is the easy way while
a do nothing loop runs in the back ground. Max RPM is 7500 or
125 pulses per second or once every 8 msec. Should be enough time
to do the simple job.

I'll gladly trade off computer speed and software simplicity for
hardware. No compiling and no chip burning. We want to keep
it as simple as possible so people with no experience in
programming or computer hardware can program it, understand it
and fix it. We also gain redundancy for safety reasons.

The injector computer will get inputs from a manifold pressure sensor, or
a mass airflow sensor and an ignition pulse. All these sensors are capable
of supplying data to more than one computer simultaneously. It is a
massive trade off of additional cheap hardware for much simpler software.

Ultimately it is designed to be used with a new generation
of small PC's in the cockpit that use flash RAM instead of hard drives.
Unlike hard drives flash ram is very rugged and works at high altitudes.

What we will do long term is use several of these real simple systems
and have them talk to one small PC in the cockpit over a simple RS232

serial

network. The PC sends out an address and the PicAXE injector with that
address responds with data. There are other data gathering modules
from www.Omega.com that work the same way. Many mixture maps
can be stored in the PC and sent to the PicAXE injector computer.

When we get one working will will build another and test it on
an actual engine on the dyno.

Here is a project I did years ago using a 6502. I was also the
designer of the Superkim and the sole owner of Microproducts.

Microprocessor-Based System for Roll-Down and Acceleration Tests
by D.K. Lynn, C.R. Derouin, and Paul Lamar
Los Alamos Scientific Laboratory
Published in IEEE Proceedings 29th Vehicular Technology Conference
(The technical details of the Lamar Instruments road test system.)
Arlington, Illinois, March 28-30, 1979


The most user friendly suppler of PicAXE parts and prototype boards
is http://world-educational-services.net/
You can actually call them and talk to a real person.
Phone:410-255-6333  The product I am buying is the AXE090 - Exper. Board

PH Anderson comes up first if you google PicAXE but it is very frustrating
doing biz with him. He does not return emails and he does not
answer his home phone let alone the fact there is no phone number
on his web site. I don't do PayPal.


Paul Lamar ...No rotor no motor.

Paul,
I like the idea of one Picaxe per injector and probably could be packaged
that way.  The cockpit computer would only be used for data storage and
program loading?  Would the Picaxes take their cue from hardware mechanical
means?  So if the cockpit cpu takes a dump the engine still runs?  Keep us
posted.  I would like to do some breadboarding as I have the 40 pin trainer.

Joe Berki
Limo EZ


Yes on the cockpit computer the cockpit computer being used only for
data storage and program loading.

The PicAXE injector computers are stand alone. Only if you want to
tune them in the air or want to display engine data is the cockpit
computer necessary.

Yes the Picaxes take their cue from hardware mechanical
means.

Yes if the cockpit cpu takes a dump the engine still runs.

Paul Lamar ...No rotor no motor.

Paul

This idea is very interesting. Along with the coil on plug idea, very
modular. It allows each rotor to be run at it best temperature as well.

Assuming two injectors per rotor, if one injector got clogged or went south
the CPU  could disable it and up the duty cycle on the remaining one.   The
cockpit CPU display would in effect be an engine monitoring system (sort of
like Mega-Tune)  and could broadcast an alarm if systems went out of spec.

Time to dust off the old 486 dinosaur on the shelf above me.
Darn, ... I was just ready to sell it along with my Tandy TRS-80 to the
Smithsonian museum of ancient artifacts:)

Doug

You don't need to do that Doug. I have figured out a way for  QB to run
very fine indeed in Windows XP. In fact it will do a few tricks that
were not possible in DOS. One of the things is the screen capture.
No longer is it entirely necessary to open a file on disk
and save the output of a program to that file. What you do is
a screen capture of the output data and paste it
into "Paint" then save it as a JPG.

That is the way this file was done.

One other trick is hit the right mouse button on the Command Prompt
and set the priorities of the window QB runs in. Took me awhile
to figure that out. Also under Shortcuts place c:\QB in
the Comes Up In box.

Make a folder called c:\QB. Unzip QB45.zip in that folder.
Click on command prompt with the left mouse button and it will come
up in that folder every time. Than type QB and QB will run. QB
has a very nice Integrated Development Environment  (IDE for short)
IMHO. It even checks your spelling and corrects some programming
mistakes automatically. Needless to say DOS QB runs EXTREMELY fast
if not instantaneously in a modern PC.

However the free PicAXE IDE is a full Windows application and is
not as fast but it does talk to the PicAXE through the USB interface
directly AND... I might add.... the PicAXE can talk back.

If you did not get the QB45.zip file I can place it on the web site
you can download it. Some ISP's don't like zip files as attachments.
Too easy to hide a virus.

Paul Lamar ...No rotor no motor.

Paul,

Yes put in on the website please.  I never have any luck opening zip files.
QB huh? The last time I touched BASIC was in the early 70s.  I assume things
have gotten better by now:)

Doug Fir


OK Yes they reached a peak just before MS pulled the plug.
Unfortunate too as the concept of a smart editor was just
getting started. Here is a better idea. Just rename this file
when you get it.

Paul Lamar ...No rotor no motor.

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