Matt, this is what the initial files look like
when a junk1 project is started. The board is up and running and
LED are blinking :)

--------------------------------------------------------

This demo is pretty close to what we are looking for. About two pages.
Not much.

The Code Warrior  IDE is rather tricky as all projects are named
"name.asm"
everything must go in a separate folder.

Here too is a short video of what the board is doing in the default
demo.

Paul Lamar

<snip


OK Paul.  That looks pretty familiar..  I'll see what I can put
together.


Matt-

I am still trying to figure out this IDE. It is all Czech to me:)

Paul Lamar


There are some sourceforge.org IDE's and sim/emulators for 6800 family
chipsets - although I have not used them so I don't know useful they
are.
Cary


OK..  I found the included files - things like tasc0 and adr are
defined there.  Kinda fills in some blanks between the device doc and
the code example..


Matt-

Here is the IDE getting started instructions in C.
I hope it is pretty much the same for asm.


-----------------------------------------------------------

Matt, any luck? Would a demo board and Code Warrior help?

Paul Lamar


What would help me with projects/hobbies like this is not having a day
job.
:)

I don't think there's that much difference between the demo program
and what you're looking for.  It's already reading the A-D converter -
but sending the value out the serial port.  I gather you want to have
the A-D value converted to a PWM output?

What's this business about the 8ms real time clock?  Is that to be the
period of the PWM signal?


Matt-


There is a timer device in there that will interrupt the processor
every
one
ms.
This can be used to build a real time clock with a resolution of 1 ms.
Something I implemented back in the late 1970's in the road test
system.

In this case I would like to use it to have the super 555 run on its
own
reading
the A To D every 16 ms and generating a PW pulse and outputting it
to the
injector switch.
No e-shaft trigger required. Saves a lot of hardware. Basically I
suspect
this is
what Tracy is doing as there is no time to sync the injection with
e-shaft
position at 7500 RPM and still get a required injection pulse width
of 90%
of 16 MS.

That A to D process and PWM process may only take a few hundred micro
seconds
at most so between 16 ms real time interrupts the super 555 is
twiddling
its
thumbs sitting around doing nothing :)

Each ms contains 1000 micro seconds so the processor is loafing
indeed:)

Paul Lamar

That's straightforward.  Should be able to come up with something this
evening.


Matt-

Paul, the sensor-A/D conversion-PWM output -injector firing cycle
doesn't
need to be completed within one  revolution of the e-shaft. It only
needs
to
be initiated once per revolution. It can actully always  fire the
injector
on the following revolution,then reset with the next trigger pulse
occuring
during the non firing time of the injector to always inject one
revolution
after the trigger pulse. The injector is obviously capable of
running at
this frequency since the  RX8 car can run at higher RPM than the
aircraft
version with race cars shifting at twice the RPM we need.

george grimes

Let me get this straight using Vince's ASCII art.
Each character is one ms. Seven MS for one rev.
The pound sign is injector dead time.
The dollar sign is injector open time.

******* ******* ******* *******
##$$$$$$$$## ##$$$$$$$$##

Now you want to do what?

Paul Lamar



Paul, at the first # sign that would coincide with the end of the
longest
injector pulse$ reset the chip and start the next trigger sequence. It
would
continue thru the 20% off cycle time required for the injector and be
waiting for the first $ sign at the beginning of injector firing. I
assume
that the start of injection would be constant and the pulse width
modulation
would vary the end of injection firing. At low fuel flow there would
be #
signs before the trigger pulse and at WOT there would be very little
 delay.
Not  to muddy the waters furthur, but what if one injector flowed
fuel fo a rich mixture at 2000 Rpm flowing continuously and the other
operated on PWM out to 7000 RPM with an overide switch on the PWM
controlled
injector to lock it on in the event of controller failure activated
by a
 no
output condition for 1/2 second.This might do away with the lower
third of
the MAF sensor output voltage where there is a lower slope voltage
response.

george grimes


Just do a similar diagram. I am still not following you.

You are not allowed to keep the injectors on all the time.
They over heat apparently. 80% is max duty cycle.


Paul Lamar




Paul, that clears up what determines the duty cycle of 80%
the$$$$## $$$$## chain is the same. The point is that we
don"t  have
 to deal with the time frame of from 36 degres before top dead center
or so
 firing the plug until the intake port closes off to do the PWM
calculation
 and complete the injectior firing. The fuel can always be injected on
the
 following intake charge each time driven by data gathered during the
 current
 intake cycle.There is the entire revolution of the e-shaft to do the
 injection of fuel and the 20% off cycle to  do the PWM
calculation.The fuel
 to air charge needs to be consistant for each intake charge and that
 implies
 turning the injector on and off once per revolution. Using an oscellator
 would seem to need both a variable frequency to get the same number of
 injector openings per intake charge and more than one per revolution
which
 is mechanically abusive on the injector parts and also require the pulse
 width modulation to set mixture. With a single injector firing per
 revolution is would at most devide the fuel between two intake
charges but
 it would be consistant from one charge to the next. Placing the injector
 the
 right distance from the port or electronically adjusting the start of
 injection would have a chance of confining the fuel to a particular
intake
 charge whereas IMHO an oscellator running at fixed  frequency and the
 engine
 tripleing its operating frquency from 2000 to 6000 RPM wouldn't.

 george grimes

 The intake port never closes. What is your point? I don't follow you.

 When do you want to start injecting and when do you want to stop
injecting?

 Just do the simple diagram.



 Hi RPM (7 ms) hi power:
 ....... ....... ....... ....... ....... ....... ....... .......
 ##$$$$$$$$$$$## ##$$$$$$$$$$$## ##$$$$$$$$$$$## ##$$$$$$$$$$$##

 Low RPM (14 ms) low power:
 .............. .............. ....... .............. ..............
 ##$$$##  ##$$$## ##$$$##

 Is this what you want to do? Inject fuel every other rev synced to some
 e-shaft angle?

 You can not turn the injector on and off in one revolution (7 ms) and
still
 have fuel as
 a function of the MAF sensor. Yes... if the pulses width is always
the same
 but then quantity of fuel injected is then a strict linear function
of RPM.
 That
 might work but why have a MAF. You don't need it. Not well but it might
 work.

 The other way is use a larger injector that will flow enough fuel at
6 ms
 for 250 HP.
 The problem with that it flows too much fuel at 1 ms and low power.
That is
 why the
 stock RX8 engine uses 6 injectors with 3 stages. It is called dynamic
 range.
 It is also why Tracy stages his four injectors in groups of two.
 It apparently has caused a lot of tuning problems.

 ----------------------------------------------------------
 ops made a mistake. This is the correct diagram.

 Hi RPM (7 ms) hi power:
 ....... ....... ....... ....... ....... ....... ....... .......
 ##$$$$$$$$$$$## ##$$$$$$$$$$$## ##$$$$$$$$$$$## ##$$$$$$$$$$$##

 Low RPM (14 ms) low power:
 .............. .............. .............. ..............
..............
 ##$$$##  ##$$$##  ##$$$##

 ---------------------------------------------------------------------

 This is what I am proposing.

 Hi RPM (7 ms) hi power:
 ....... ....... ....... ....... ....... ....... ....... .......
 ##$$$$$$$$$$$## ##$$$$$$$$$$$## ##$$$$$$$$$$$## ##$$$$$$$$$$$##

 Low RPM (14 ms) low power:
 .............. .............. .............. ..............
..............
 ##$$$##  ##$$$## ##$$$## ##$$$## ##$$$##

 Notice that injection takes place at different points in the cycle.


 Paul Lamar


Paul, If the space between the pound signs ####  #### represents theapex
seal passing the port closing point we are indeed on the same page. I
just
got the impression that the switch to the microcomputer chip was
abandoning
the trigger signal in favor of an oscellator not syncronized with the
engine.

george grimes

No it does not. The space between the dots represent one e-shaft TDC.
Since the rotor runs at one third e-shaft speed it could also represent
the apex seal passing the floor of the intake p-port. The RPM can be
calculated by counting the dots. 7 dots is 7 ms 143 revs per second or
8,570 RPM. 14 dots is  4,286 RPM.

Each character on the line being a space or any other character
represents one ms.

The pound sign indicates the mandatory off time for injector cooling.
The total off times is # + what ever space characters are there.

This scheme was invented by Vince and it is a good clear way of
illustrating
injection timing. Thanks  Vince.

Paul Lamar


What does that diagram look like at 75% power at 6000RPM?

Victor Roberts


6000 RPM (10 ms) 70% power:
.......... .......... .......... .......... .......... ..........
##$$$$$$$$$##___ ##$$$$$$$$##___ ##$$$$$$$$##___ ##$$$$$$$$##

I added an underline character to keep word wrap from screwing things up:)
Nothing happens during the under line character.

Paul Lamar