BS1 ECU for mower engine
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Posts: 46,084
Richard,
The intention is to set up the vehicle service area with 12v flood lamps.
The compressor is also required to pump up tyres (I forgot to mention that).
I wouldn't worry about open loop control. Any race car you look at runs
open loop, as do most (if not all?) production cars at wide open throttle as
you need to have steady state driving to run closed loop anyway. A lot of
aftermarket engine computers for racing don't even offer closed loop as it
doesn't get used.
There shouldn't be a problem having a lookup table of RPM vs Thottle
position (8x8 matrix)- its a bit rough I know - but then again its only a
generator/compressor and not a high performance engine.
Also, to Stephen - there are many 4wder's out there that would dispute that
a air conditioning compressor is not suitable as a compressor - HEAPs of
people use them and use an idle up switch to stop the car from stalling
whilst pumping up tyres.
I still haven't worked out how to read in the tacho signal without slowing
down the program waiting to count ignition signals and I'm certainly open
for suggestions.
Thanks for your input guys.
Matt
Original Message
Subject: Re: Re:ECU projects
how about using the battery in your car. I have seen 12 volt impact wrenches
and 12 volt trouble lights
(use voltage divider to get ignition signal off of coil primary - condition
as necessary)
good luck on your open loop injector control
you might get by with out an o2 sensor but Ill bet you will need to know
engine load (intake vacuum)
richard
Original Message
From: "Matt Swan @ home" <matt_swan@b...>
To: <basicstamps@yahoogroups.com>
Sent: Monday, November 19, 2001 7:15 AM
Subject: [noparse][[/noparse]basicstamps] Re:ECU projects
> Hi guys,
>
> I've been a bit slack reading this group lately but I've been thinking
about
> making a BS1 ECU for my lawnmower for a few months now and now you've got
me
> thinking about it again....
> How's this for a dumb idea...
> I need a portable 12v power and compressor setup for use in the forest for
> servicing my rally car....
> A motor mower engine will be hooked up to an old car alternator and an air
> conditioning compressor. The compressor is hooked up to a BBQ gas bottle
> giving me a supply of compressed air to run a "rattle gun". The
alternator
> will run the work lights.
> The Stamp is used to run the engine as follows:
> Use PWM to drive an old remote contol cars servo motor to open and close
the
> throttle.
> Keep the existing magneto ignition for simplicity.
> The stamp also fires the injector (not timed to the engine rpm) -
> carburettors aren't!
> Monitor engine rpm and increase/decrease fuel as appropriate to keep
engine
> running at the correct rpm (idle).
> As soon as a work lamp is switched on (high currenty draw) or the BBQ
bottle
> runs low on pressure open up the throttle to avoid stalling before
switching
> the compressor back on.
>
> I've got some of it worked including an algorithm to prevent "hunting" in
> the motor. The only bit I can't wortk out is how to pick up a RPM signal
> off the magneto. Anyone got any ideas? As far as I can tell, getting the
> Stamp waiting for tacho signals will "pause" the program while it waits,
> slowing down its response time to a stalling engine. Hmmm, maybe I could
> use a freq2volt converter then read in the analog value - that'd be
> quicker.... anyone got a better idea???
>
> I figure the rest of it can't be that hard... Then again, the marshmallow
> toaster seems like a way cooler project....
>
> PS. For anyone else trying this, "dyi_efi" even has links to show you how
> to run a fuel injector properly off a parallel port so running it off a
> Stamp can't be that hard.
>
> PSS sorry for rambling - it's late...
>
> Regards,
>
> Matt
Message: 22
Date: Mon, 19 Nov 2001 11:02:36 -0800
From: "Stephen H Chapman"
Subject: Re: Re:ECU projects
An Air cndx compressor is not useable in this job.
Original Message
From: "Matt Swan @ home" <matt_swan@b...>
To: <basicstamps@yahoogroups.com>
Sent: Monday, November 19, 2001 5:15 AM
Subject: [noparse][[/noparse]basicstamps] Re:ECU projects
The intention is to set up the vehicle service area with 12v flood lamps.
The compressor is also required to pump up tyres (I forgot to mention that).
I wouldn't worry about open loop control. Any race car you look at runs
open loop, as do most (if not all?) production cars at wide open throttle as
you need to have steady state driving to run closed loop anyway. A lot of
aftermarket engine computers for racing don't even offer closed loop as it
doesn't get used.
There shouldn't be a problem having a lookup table of RPM vs Thottle
position (8x8 matrix)- its a bit rough I know - but then again its only a
generator/compressor and not a high performance engine.
Also, to Stephen - there are many 4wder's out there that would dispute that
a air conditioning compressor is not suitable as a compressor - HEAPs of
people use them and use an idle up switch to stop the car from stalling
whilst pumping up tyres.
I still haven't worked out how to read in the tacho signal without slowing
down the program waiting to count ignition signals and I'm certainly open
for suggestions.
Thanks for your input guys.
Matt
Original Message
Subject: Re: Re:ECU projects
how about using the battery in your car. I have seen 12 volt impact wrenches
and 12 volt trouble lights
(use voltage divider to get ignition signal off of coil primary - condition
as necessary)
good luck on your open loop injector control
you might get by with out an o2 sensor but Ill bet you will need to know
engine load (intake vacuum)
richard
Original Message
From: "Matt Swan @ home" <matt_swan@b...>
To: <basicstamps@yahoogroups.com>
Sent: Monday, November 19, 2001 7:15 AM
Subject: [noparse][[/noparse]basicstamps] Re:ECU projects
> Hi guys,
>
> I've been a bit slack reading this group lately but I've been thinking
about
> making a BS1 ECU for my lawnmower for a few months now and now you've got
me
> thinking about it again....
> How's this for a dumb idea...
> I need a portable 12v power and compressor setup for use in the forest for
> servicing my rally car....
> A motor mower engine will be hooked up to an old car alternator and an air
> conditioning compressor. The compressor is hooked up to a BBQ gas bottle
> giving me a supply of compressed air to run a "rattle gun". The
alternator
> will run the work lights.
> The Stamp is used to run the engine as follows:
> Use PWM to drive an old remote contol cars servo motor to open and close
the
> throttle.
> Keep the existing magneto ignition for simplicity.
> The stamp also fires the injector (not timed to the engine rpm) -
> carburettors aren't!
> Monitor engine rpm and increase/decrease fuel as appropriate to keep
engine
> running at the correct rpm (idle).
> As soon as a work lamp is switched on (high currenty draw) or the BBQ
bottle
> runs low on pressure open up the throttle to avoid stalling before
switching
> the compressor back on.
>
> I've got some of it worked including an algorithm to prevent "hunting" in
> the motor. The only bit I can't wortk out is how to pick up a RPM signal
> off the magneto. Anyone got any ideas? As far as I can tell, getting the
> Stamp waiting for tacho signals will "pause" the program while it waits,
> slowing down its response time to a stalling engine. Hmmm, maybe I could
> use a freq2volt converter then read in the analog value - that'd be
> quicker.... anyone got a better idea???
>
> I figure the rest of it can't be that hard... Then again, the marshmallow
> toaster seems like a way cooler project....
>
> PS. For anyone else trying this, "dyi_efi" even has links to show you how
> to run a fuel injector properly off a parallel port so running it off a
> Stamp can't be that hard.
>
> PSS sorry for rambling - it's late...
>
> Regards,
>
> Matt
Message: 22
Date: Mon, 19 Nov 2001 11:02:36 -0800
From: "Stephen H Chapman"
Subject: Re: Re:ECU projects
An Air cndx compressor is not useable in this job.
Original Message
From: "Matt Swan @ home" <matt_swan@b...>
To: <basicstamps@yahoogroups.com>
Sent: Monday, November 19, 2001 5:15 AM
Subject: [noparse][[/noparse]basicstamps] Re:ECU projects
Comments
> down the program waiting to count ignition signals and I'm certainly open
> for suggestions.
Automotive "Speed-Density" systems do not read RPM's,
Simply wrap a few turns of the center conductor of a piece of coax around
the coil-wire or plug-wire and ground the shield. Feed the other end of the
center conductor through a resistor (say 100k - 10M) and connect it to the
Gate lead of an N-channel mosfet. Connect the Cathode side of a diode from
the resistor - Gate connection and the Anode to ground to prevent the Gate
signal going more negative than ground. Parallel another resistor across
this diode to pull the gate low. Connect another diode's Anode to the
resistor - Gate connection and it's Cathode to 12v to prevent the gate
signal from going too far positive. Ground the Source lead of the mosfet.
And tie a pull-up resistor (say 1K) from the mosfets Drain lead to the 5volt
rail. Finally connect a 47K resistor from the Drain lead - pull-up resistor
connection to the stamps input.
Each time the ignition fires, the mosfet will pulse the input low, your
program will then pulse the injector for a period of time relative to the
voltage reading from the "Manifold Absolute Pressure" sensor.
Thus for a given quaintly of air taken in in one revolution, you will
provide the appropriate amount of fuel to go with it.
closed intake valve ?
richard
Original Message
From: "FalconWireless Tech Support - KF4HAZ"
<techsupport@f...>
To: <basicstamps@yahoogroups.com>
Sent: Tuesday, November 20, 2001 9:26 AM
Subject: Re: [noparse][[/noparse]basicstamps] Re: BS1 ECU for mower engine
> > I still haven't worked out how to read in the tacho signal without
slowing
> > down the program waiting to count ignition signals and I'm certainly
open
> > for suggestions.
>
> Automotive "Speed-Density" systems do not read RPM's,
> Simply wrap a few turns of the center conductor of a piece of coax around
> the coil-wire or plug-wire and ground the shield. Feed the other end of
the
> center conductor through a resistor (say 100k - 10M) and connect it to the
> Gate lead of an N-channel mosfet. Connect the Cathode side of a diode from
> the resistor - Gate connection and the Anode to ground to prevent the Gate
> signal going more negative than ground. Parallel another resistor across
> this diode to pull the gate low. Connect another diode's Anode to the
> resistor - Gate connection and it's Cathode to 12v to prevent the gate
> signal from going too far positive. Ground the Source lead of the mosfet.
> And tie a pull-up resistor (say 1K) from the mosfets Drain lead to the
5volt
> rail. Finally connect a 47K resistor from the Drain lead - pull-up
resistor
> connection to the stamps input.
> Each time the ignition fires, the mosfet will pulse the input low, your
> program will then pulse the injector for a period of time relative to the
> voltage reading from the "Manifold Absolute Pressure" sensor.
> Thus for a given quaintly of air taken in in one revolution, you will
> provide the appropriate amount of fuel to go with it.
>
>
> To UNSUBSCRIBE, just send mail to:
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Body of the message will be ignored.
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>
>
Original Message
> so when the plug fires - you start injecting fuel on to the back side of
a
> closed intake valve ?
>
> richard
Most if not all automotive fuel injection systems do it that way.
The assumption is that the air used last stroke will be pretty close to the
amount need for the next, after all there is only about 32 ms between the
two.
> lamps. The compressor is also required to pump up tyres (I forgot to
> mention that).
Have you considered using a scuba tank for the tyres ?
You can get what they call a "Pony bottle" which is about the size
of a fire extinguisher and will do a few tyres.
Steve.
======================================================
Steve Baldwin Electronic Product Design
TLA Microsystems Ltd Microcontroller Specialists
PO Box 15-680, New Lynn http://www.tla.co.nz
Auckland, New Zealand ph +64 9 820-2221
email: steveb@t... fax +64 9 820-1929
======================================================
> so when the plug fires - you start injecting fuel on to the back side of a
> closed intake valve ?
>
> richard
This would work. Batch fire systems do this by firing each injector once
per revolution, all at the same time. Bank to back systems fire half of
the injectors each revolution. Sequential systems fire each injector once
per revolution, one at a time according to the firing order of the engine.
The valve will eventually open and intake the charge of air and fuel.
FWIW,
--
Dale Harwood [noparse][[/noparse] N4VFF ]
internet> dale@h...
ax.25> n4vff@n4vff.#cha.tn.usa.noam
#include <std_disclaimer.h>
> This would work. Batch fire systems do this by firing each injector once
> per revolution, all at the same time. Bank to back systems fire half of
^^^^
should read bank...
> the injectors each revolution. Sequential systems fire each injector once
> per revolution, one at a time according to the firing order of the engine.
>
> The valve will eventually open and intake the charge of air and fuel.
>
> FWIW,
>
>
--
Dale Harwood [noparse][[/noparse] N4VFF ]
internet> dale@h...
ax.25> n4vff@n4vff.#cha.tn.usa.noam
#include <std_disclaimer.h>