All you guys in Oz & Nz got to get a Jan 14 back issue as there is an
article on how to build an EFI with a low cost Arduino micro
computer. This will be a good education in EFI's. I ordered a copy
for me shipped to the US for $15 Oz
Silicon Chip mag is a great Oz publication for buying and learning
electronics.
http://siliconchip.com.au/
What works on one cylinder works on one rotor. It's cheap enough to
dup it for the second rotor.
Don't mess around. They will be sold out of Jan back issues shortly.
Paul Lamar
I strongly recommend Arduino kit. I made some by Ebay's chinese
circuit. mostly charging battery and drill and soldering. but as
going study harder. most circuit already on Ebay or any hardware
store. only left thing is controller.
Arduino is very very cheap and most of all it's programming language
and IDE is most valuable. just plug in via USB and install IDE(
programming software) you can programming micro computer . and there
is already so many example at IDE, ( IDE is just same as word
processor, it's programmer's word processor ) there is so many
tutorial about this.. I just pick this. but you can search all about
it.
http://www.youtube.com/watch?v=E6KwXYmMiak
<http://www.youtube.com/watch?v=E6KwXYmMiak>
making 3D printer or CNC also very easy. there is already part and
firmware there. and we can use this as almost everything. we can use
it monitoring voltage at sensor so on.
http://www.youtube.com/watch?v=85LvW1QDLLw
<http://www.youtube.com/watch?v=85LvW1QDLLw>
http://www.youtube.com/watch?v=gDFeXYWxQ_Y
<http://www.youtube.com/watch?v=gDFeXYWxQ_Y>
IT's key is easy to programming. that's the key and there is already
many tutorials and datas. I recommend it as software engineer
expert.
P_Bear.
Hi. Paul
Thank you for response my email.
and please search web about Arduino and EFI.
almost all EFI system already made by Arduino. so you can just copy
and paste program code for making Rotary EFI system. very easy and
simple. we can save so many days.
https://www.google.co.kr/search?q=arduino+efi&ie=utf-8&oe=utf-8&rls=org.mozilla:en-US:official&client=firefox-a&gws_rd=cr&ei=F9zdUp_lMIj4kAXaoYGoCQ
<https://www.google.co.kr/search?q=arduino+efi&ie=utf-8&oe=utf-8&rls=org.mozilla:en-US:official&client=firefox-a&gws_rd=cr&ei=F9zdUp_lMIj4kAXaoYGoCQ>
just click this. all engine already have code.
P_Bear
Can you send us some more well commented Arduino source code?
This is good stuff as the Arduino is a much more powerful processor
than the Mega-squirt
and it is far easier to program.
Paul Lamar
To start the mower I set the pulse width to 5ms with the pot on my
control panel. Thats the amount needed for idle condition. When I want
to mow or engage the mower deck I turn the pulse width up to 11 or 12ms
and raise the throttle lever to full throttle this opens my throttle
body (old carb) about 10%. From here the governor and the code below
handle everything else. If the engine goes under load the governor
kicks in and opens the throttle body turning the pot connected to the
governor, so if the governor pot reads 980 I subtract that from 1000 and
add it to the value of my fuel trim pot, now we have 1000-980+11 = 31ms
injector pulse. Then the engine RPM's recover and the governor pulls
back to 1000.
I really need to do a youtube video of this cutting the lawn.
Best of all ----> Next year my mower will start up and run smiley
I will be putting together a schematic soon..
void loop()
{
Govval = analogRead(Govpin);
Govval = map(Govval, 0, 1023, 1,1000);
val = analogRead(potpin);
val = map(val, 0, 1023, 0, 20);
digitalWrite(InjectorPin, HIGH); // set the injector on
delay( 1000 - Govval + val); // on pulse width
digitalWrite(InjectorPin, LOW); // set the injector off
delay(25-val); // off width
UpdatePause++;
if( UpdatePause > 8 )
{
UpdateLCD();
UpdatePause = 0;
}
}
I will be putting together a schematic soon..
Quote
One question that comes up is, how do you (or the arduino) know
when to fire the injector? I could see potentially using a hall effect
sensor to pick up the magnets on the flywheel, but I'm curious to how
you are timing things.
You only need to know when to fire if you're going for some sort of
sequential setup or a setup that only fires when the intake valve is
open. Otherwise it doesn't matter, as long as the fuel makes it into the
manifold it's good. That's how bank and batch fire used to run and is
how modern sequential runs under heavy load.
As for O2 feedback, that adds A LOT of code. I'm using an arduino
for my Yamaha 535 EFI project(fuel only, spark comes later) and it will
have feedback so I'll let you see the code then. Also requires a table
that you can write back to, interrupts from the crank so you don't go
too long modifying tables and miss fuel injection cycles, and a map
sensor so you can take load vs rpm and find your injection rates in the
table... should be an interesting project
--Joe
delay( 1000 - Govval + val); // on pulse width
digitalWrite(InjectorPin, LOW); // set the injector off
delay(25-val); // off width
This might work OK on the lawnmower engine, but the delay function
literally stops the code for the allotted amount of time defined in the
function. While in the delay, no additional code executes which I have
found to be an issue with a functional high speed system. Here you
appear to have a delay of 1000 before the other variables are deducted
from it, and another of 25 - another variable. A delay of up to 1025 us
is significant at the 8000 rpm that I plan for takeoff.
A better way to handle the intent of the delay would be to use the
timer- look up "blink without delay" and look at the code.
As far as firing the plugs and the injectors, you could use the
switch/case function. It works well.
Also, the analogRead and digitalWrite functions slow the program down
quite a bit as well. Again, for a lawnmower it probably works. For the
rotary I see no way to make it fast enough.
Kevin Alderman
What about one Arduino per injector?
Paul Lamar
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