-----------------------------------------------------
Here is a company that embeds the BASIC
interpreter into
the PIC. These are so cheap and so easy to use
everybody on
here should buy one of these things and play with
it.
Your knowledge on EFI computer systems will
immediately jump to a
higher plateau. Tons of Internet support.
http://www.rev-ed.co.uk/picaxe/
http://www.picaxe.org/
http://www.phanderson.com/picaxe/picaxe.html
http://www.hippy.freeserve.co.uk/picaxeqa.htm
http://dave.fraildream.net/picaxe/index.shtml
Attached is the 73 page clearly written manual. It
includes a
tutorial on the version of BASIC used to program
the chips.
Interestingly you can use a graphical method of
programming
which is very easy to learn. It basically is a
visual
representation of your program in flow chart form.
You arrange
the building blocks on the computer screen and and
it writes the
program for you. A lot like what you did in
kindergarten :)
--------------------------------------------------------
Here a program that controls a DC motor. It is the
heart
and soul of the simple constant dribble EFI
system. This is
it! There is little more.
http://www.phanderson.com/picaxe/pwm.html
BTW no returning hot fuel to the fuel tanks.
-----------------------------------------------------
I went on the PICAXE web site and downloaded the
27 meg free
programming editor.
http://www.rev-ed.co.uk/picaxe/
This is the greatest thing since sliced bread
when it comes to programming. I wrote my first
program in 30 seconds
using the Kindergarten blocks.
Not only that but they have included a free
simulator.
My 3 line program program blinks a green light.
The simulator
is animated and it steps through your program over
and over
again while the green light on the screen blinks
on and off.
Here is a screen capture from my Windoze computer.
It also gives you BASIC and assembler source
listings.
All I can say is WOW! This is way beyond clay and
everybody
can become Leonardo da Vinci of programming.
I wish I had something like this when I wrote my
first year long
6502 assembler program for the first $5000 Lamar
Instruments Real
Time Road Test System that then Managing Editor
John Dinkel on
here bought for Road & Track magazine way back in
1975.
That got me a super head start in computers.
Thanks again John
for your trust and belief in me. Which eventually
allowed me to
do the last picture :) (Not Robin :)) I forgot her
name :)
BTW NO expensive solenoid fuel injectors to plug
up or fail.
No fuel injector bungs welded to intake tubes. No
fuel rails.
No pressure regulators. No fuel return lines to
the fuel tanks.
The EFI constant dribble fuel hardware system
under the cowl
consist of only two -4 AN fuel hoses. One for each
rotor.
That's it!!!!! It feeds fuel to the engine only in
the amount
it needs for the prop load at the moment.
We are looking at nothing short of a revolution in
low
cost EFI systems for aircraft engines here IMHO.
Paul Lamar ...No rotor no motor.
I agree with you.
Is there a US distributor? I would like to buy a
PICAXE system without the
delay of transatlantic delivery.
The BASIC language is a great one for teaching. The
PICAXE system should be
an ideal learning environment. In my case I wish to
learn the hardware side
of the equation.
A word of caution however. BASIC tends to be slow.
The PICAXE system has
only a polled interrupt; this has lots of
performance implications. A polled
interrupt (purists would argue that it is not a
hardware interrupt at all)
places a high overhead on the system. The result is
that one PICAXE might
not be able to handle the real time requirements.
Then again it might. AND a
complete system could incorporate more than one to
share the load. Caveat
emptor!
Will work up a draft system diagram for your
consideration. Hardware must
come before software.
Doc Custer
Retired Software Engineer and sometime Audiologist
That was true in the old days but these things
average 10,000
BASIC instructions per second as I recall.
That's at 4 megahertz. One ass. instruction per
microsecond
or one million ass. instructions per second.
Some of the 28 pin and 40 pin PICAXE chips will
clock
at 16 megahertz or 40,000 BASIC instructions per
second.
This is a compiler and not a interpreter. I was
wrong
about it being an interpreter.
You might have to do a bit of assemble languages to
use the
hardware interrupt. Try the polling interrupt first.
The simple version don't have a lot to do so it can
spend
most of the time polling.
Try www.world-education-services.com
email masc1@usa.net
www.panderson.com
Paul Lamar ...No rotor no motor.
Paul,
I highly recommend buying PicAxe products from Peter
Anderson. His prices and support are great, and
shipping costs are low. FYI, the link above is
missing the 'h'. Proper link below:
http://www.phanderson.com/
I've used the PicAxe on a few projects myself. It's
an amazing micro for those who want to get up and
running quickly. It's an unbeatable value, certainly
taking a bite out of Parallax's BasicStamp market.
I'm watching with interest your cheap efi ideas.
There are some similarities to the Ellison TBI.
Proper fuel filtration will be very important. Those
tiny fuel distribution holes could easily get plugged
by contaminants.
Roger Enns.
Yep. One advantage of the low pressure system. Bigger holes.
------------------------------------------------------
Looks like the PIXAXE comes with free glass cockpit software.
If you connect a small laptop computer that will run the
PIXAXE software a command is built in called "debug" that
will display on the computer screen up to a dozen engine
parameters. OBD II for your aircraft engine :)
Is that cool or what?
---------------------------------------------
Oh-my-God it gets better than that.
"..................GPH equals xxx" .
"..................RPM equals rrr"
"Fuel pump pulse width equals ppp"
"......Intake air temp equals ttt"
"..................MAP equals mmm"
etc., etc., etc..
Up to a dozen or so is displayed on the lap top screen.
No extra cost. All FREE!!! DOUBLE WOW WOW!!!!!!!!!
THIS IS AMAZING! I AM STUNNED!
--------------------------------------------
OK here is a 10 inch wide screen Fujitsu tablet computer you
can mount on the instrument panel for your PIXAXE glass
cockpit. The keyboard can be hidden behind the screen on tablet
computers. Go to Fry's and buy GPS moving road map software
which includes a GPS PC card receiver for another $150.
Paul Lamar ...No rotor no motor.
Paul
How do you interpret PIXAXE warnings about not using the chip in anything
that is mission critical. In this case they were talking about the noisy
environment of a car. Wouldn't an airplane be worse or is their verbiage
just covering one's ass talk?
"Can I use a PICAXE in a Mission Critical System??
Possibly, but think long and hard before you do.
It is necessary to understand what the system which includes the PICAXE is
meant to do and the consequences should it fail or malfunction. If a failure
or malfunction may put a life in danger, or lead to a life being put in
danger, then it is a Safety Critical System and a PICAXE must not be used.
What may at first appear not to be a Safety Critical System may turn out to
be so. A system fitted to a vehicle may not appear Safety Critical at first
glance, but even something as apparently benign as an interior light delay
circuit or a car burglar alarm in a failure mode could affect the vehicle's
electrical system and lead to the loss of power and consequently affect
steering, braking and other safety systems during driving. Such faults can
obviously be life threatening, to passengers and others, even if not the
driver, and such systems must therefore be considered as Safety Critical by
consequence. That is why you should never fit a PICAXE system to an
automobile's power supply or interface it to any other vehicle electronics."
Doug Fir
--------------------------------------------
Just covering their butts. No processor is immune to interference.
If your worried about it use an all mechanical system. No EFI
system is immune. More depends on the box you put it in and the
power supply than anything else.
Doc is going to use backups like Tracy does. These things are so
cheap you could use two per rotor. Same goes for fuel pumps. Two
per rotor.
BTW National Semi refuses to sell any chips to the medical industry.
PICAXE chips are made by Microchip. If Microchip excluded themselves
from the auto industry their sales would take a nose dive.
All PICAXE does is load a boot loader program into permanent
PIC memory and resell the PIC chip as a PICAXE chip.
For Microchip's policy check out:
http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=64
--
Paul Lamar ...No rotor no motor.
Paul,
Thanks for the info on Microchip.
In the six weeks I was away did you find a way to use the constant spray
slide throttle system with a turbo charged engine? I checked out your
latest drawings on the website. Correct me if I am wrong but it appears the
latest configurations is quite an improvement over the gravity flow system
and if I am not mistaken it is a low pressure electronic fuel flow
controller.
You probably had lots of discussions about this design but something Matt
just commented on makes me wonder why the need of a pressure regulator. A
small pressure tank with an internal diaphragm to dampen out the pulses I
can understand.
Let me see if I got this right.
If the throttle is opened, more holes are uncovered and fuel pressure must
drop. The fuel pressure sensor then responds by having the duty cycle of the
pump increased to maintain the required flow pressure. Since we can only
push so much fuel through a little hole and pressure will increase faster
than flow, fuel flow is tied to throttle setting and how many holes
(injectors) are open at the time.
If that is the case then changing the duty cycle by tweaking the fuel
pressure control would act as a leaning mechanism right?
It seems we are trying to control flow where controlling pressure through
what are basically will be a series of optimum shaped injectors might
accomplish the same aim?
Doug Fir
By constant spray I think you are talking about the all mechanical
constant drip system. The answer is no. I think you need a computer
with a turbo engine as there are a lot of other things that you
might want to control such as a waste gate.
For a non turbo engine controlling the leaning by the pressure
regulator knob in the mechanical constant drip system sounds like
a very good idea. Eliminates the needle valve. A further
simplification. Mount the pressure regulators on the instrument
panel with the knobs accessible by the pilot. Good idea. See
the attached 3D. The required return lines from the pressure
regulators to the fuel tanks are not shown (yet).
The second idea is to combine features of both a pure EFI system
and the all mechanical system and use a
PICAXE to PWM the fuel pump directly and thereby control
the amount of fuel going to each runner. No needle leaning valve, no
fuel injectors, no fuel rail, no pressure regulators and no return lines.
Only the PICAXE and the fuel pump. The advantage is the glass
cockpit feature is free and at not extra cost as the PICAXE BASIC
language can send ASCII strings and engine data to a note book or
other small computer running PICAXE software mounted on the
instrument panel.
Sony UX series.
http://www.sony-discounts.com/
# 4.5" Wide SVGA LCD, Touch Screen 1
# Integrated Wireless Wide Area Network (WAN)3
accessing singular Wireless National EDGE Network with
SmartWi™ technology
# 1GB RAM and 32GB Flash Memory
There is lots of cheap moving map software both aviation and road
(IFR "I Follow Roads" :)) that will run on this computer. Not only
that you can use it as a cell phone. Low cost GPS's receivers are
available in USB form. When you are not flying unplug it from the
PIXAXE and use it as your main cell phone/computer/Internet connection.
Access the web weather maps when you are in the wireless fixed base
operator.
I have not gotten around to doing a 3D yet. Doc's diagram is all
we have at the moment.
Paul Lamar ...No rotor no motor.
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