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Is a stamp 2 quick enough?.... — Parallax Forums

Is a stamp 2 quick enough?....

ArchiverArchiver Posts: 46,084
edited 2003-10-07 17:22 in General Discussion
in this program below, i have it setup to inject fuel from a fuel
injector that is triggered by input 15 going high which is a magnetic
coil pick up with a 10k resistor from the input pin going to 5+ ...
when i have this program running on my engine it will idle and pull
up to around 1500~2000 rpm's (25 ~ 33 times a second input15 is being
pulled high) but once i give it full thottle or 3/4''s thottle it
will start to rev up then die and rev up and die, but i tried fooling
around with the pulseout command to have it open up more to alow more
fuel into the engine but for some reason still acts the same, am
starting to think that ither the stamp isnt keeping up with magnetic
pick up coil, or could i be over driveing the input coil with the
engien rev'ing up so high it pulses to much current/voltage into the
input15...... or is my stamp not being able to be triggered quickley
enoguh so it can open injector and look back to it self once
more .... ive heard from other people stamp 2 can only go so fast but
i figure if im runing my engine with in 5000~6000 rpm range that it
should be able to see the input pin, trigger the sub routine, read
the thottle postion then do the lookup command for the correct pulse
for the injector and loop back to its self agian....

another question would be , in dealing with magnetic pick up coils
and interfaceing them into the stamp, i probley need a better way to
interface the two, in low rpm's it works fine but i have no idea how
to tell if the stamp is realling reading every time the input is high
then low agian or if its "skipping" sometimes across the coil
pickup....

also befor i forget... on the injector, i have a NPN power swithcing
transistor to switch the state of the injector off/on , i have it
setup where the base is pluged directly into the stamps output pin,
the collector pluged into the ground and the emitter pluged into the
injector and the other wire for injector is pluged into 12+ dc...


hopefully someone can help me with this it sucks to see it my
invention work but still have bugs in it... let me know what u guys
think...

Sean...




'{$STAMP BS2}
TB_POS VAR BYTE
X VAR WORD
x0 CON 1300
x1 CON 1700
x2 CON 2000
x3 CON 3000
x4 CON 4000
x5 CON 4000
x6 CON 5000
x7 CON 6000
x8 CON 8000
x9 CON 10000
x10 CON 12000
x11 CON 13000
x12 CON 14000

MAIN:

input 15

IF IN15 = 1 THEN tb
goto main

TB:

PULSIN 8, 1, TB_POS
lookup TB_POS min 5 max 18 - 5,
[noparse][[/noparse]x0,x1,x2,x3,x4,x5,x6,x7,x8,x9,x10,x11,x12], x
pulsout 7,x
GOTO MAIN


**********end of programm

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2003-10-07 03:35
    Have you tried grounding the injector apart from the transistor? See
    if it gets any higher RPM's? I ask this because an ECU not only reads
    RPM but air flow as well. It could be via speed density or mass flow.
    Your program doesn't read any of this so the engine runs lean.

    Just a thought. Good luck.


    --- In basicstamps@yahoogroups.com, "djrevolution99"
    <djrevolution99@y...> wrote:
    > in this program below, i have it setup to inject fuel from a fuel
    > injector that is triggered by input 15 going high which is a
    magnetic
    > coil pick up with a 10k resistor from the input pin going to 5+ ...
    > when i have this program running on my engine it will idle and pull
    > up to around 1500~2000 rpm's (25 ~ 33 times a second input15 is
    being
    > pulled high) but once i give it full thottle or 3/4''s thottle it
    > will start to rev up then die and rev up and die, but i tried
    fooling
    > around with the pulseout command to have it open up more to alow
    more
    > fuel into the engine but for some reason still acts the same, am
    > starting to think that ither the stamp isnt keeping up with
    magnetic
    > pick up coil, or could i be over driveing the input coil with the
    > engien rev'ing up so high it pulses to much current/voltage into
    the
    > input15...... or is my stamp not being able to be triggered
    quickley
    > enoguh so it can open injector and look back to it self once
    > more .... ive heard from other people stamp 2 can only go so fast
    but
    > i figure if im runing my engine with in 5000~6000 rpm range that it
    > should be able to see the input pin, trigger the sub routine, read
    > the thottle postion then do the lookup command for the correct
    pulse
    > for the injector and loop back to its self agian....
    >
    > another question would be , in dealing with magnetic pick up coils
    > and interfaceing them into the stamp, i probley need a better way
    to
    > interface the two, in low rpm's it works fine but i have no idea
    how
    > to tell if the stamp is realling reading every time the input is
    high
    > then low agian or if its "skipping" sometimes across the coil
    > pickup....
    >
    > also befor i forget... on the injector, i have a NPN power
    swithcing
    > transistor to switch the state of the injector off/on , i have it
    > setup where the base is pluged directly into the stamps output pin,
    > the collector pluged into the ground and the emitter pluged into
    the
    > injector and the other wire for injector is pluged into 12+ dc...
    >
    >
    > hopefully someone can help me with this it sucks to see it my
    > invention work but still have bugs in it... let me know what u guys
    > think...
    >
    > Sean...
    >
    >
    >
    >
    > '{$STAMP BS2}
    > TB_POS VAR BYTE
    > X VAR WORD
    > x0 CON 1300
    > x1 CON 1700
    > x2 CON 2000
    > x3 CON 3000
    > x4 CON 4000
    > x5 CON 4000
    > x6 CON 5000
    > x7 CON 6000
    > x8 CON 8000
    > x9 CON 10000
    > x10 CON 12000
    > x11 CON 13000
    > x12 CON 14000
    >
    > MAIN:
    >
    > input 15
    >
    > IF IN15 = 1 THEN tb
    > goto main
    >
    > TB:
    >
    > PULSIN 8, 1, TB_POS
    > lookup TB_POS min 5 max 18 - 5,
    > [noparse][[/noparse]x0,x1,x2,x3,x4,x5,x6,x7,x8,x9,x10,x11,x12], x
    > pulsout 7,x
    > GOTO MAIN
    >
    >
    > **********end of programm
  • ArchiverArchiver Posts: 46,084
    edited 2003-10-07 05:57
    In a message dated 10/6/2003 7:44:06 PM Pacific Daylight Time,
    cozz.home@v... writes:
    Have you tried grounding the injector apart from the transistor? See
    if it gets any higher RPM's? I ask this because an ECU not only reads
    RPM but air flow as well. It could be via speed density or mass flow.
    Your program doesn't read any of this so the engine runs lean.

    Just a thought. Good luck.
    ++++++++++++++++++++++++++++++++++++++++++++++

    Don't ground it for very long though, inductors are not meant to continuously
    pass current. On a 4 cylinder gasoline engine, the maximum injector pulse
    width is in the neighborhood of 25 mS, give or take.....it's been a few years
    since I actually looked at the max on time.


    [noparse][[/noparse]Non-text portions of this message have been removed]
  • ArchiverArchiver Posts: 46,084
    edited 2003-10-07 17:22
    As the rpm goes higher the width of the pulse and possibly the amplitude
    drops as well. It is necessary to condition this signal so that it is the
    same at all rpms. (one-shot). You need to check the switching speed of the
    transistor you are using to trigger the injector and verify it can switch at
    the speeds you are running. You may need to use a more complex circuit to
    turn off the device more quickly (possibly a circuit to applay a reverse
    voltage on switch off to force a more rapid and controlled turn off), and
    you should isolate the base from the stamp with as a minimum a resistor so
    as to not require excess current under all switching conditions. This type
    of control is more complex than initially conceived and you should emulate
    the control without stamp control and then interface the stamp to give the
    same operational results. A large value capacitor is typically used to
    supply initial current to get a very quick turn on.

    jim
    http://www.geocities.com/jimforkin2003/


    Original Message
    From: djrevolution99 [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=lU-GXa86F3aSdYhZaY3TYlTh7Uy5Q0AGu5CUtU1qXcuIoUA15L77C0biT8LtLmSLsThifU3R4q5YYtMON3I]djrevolution99@y...[/url
    Sent: Monday, October 06, 2003 6:11 PM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] Is a stamp 2 quick enough?....


    in this program below, i have it setup to inject fuel from a fuel
    injector that is triggered by input 15 going high which is a magnetic
    coil pick up with a 10k resistor from the input pin going to 5+ ...
    when i have this program running on my engine it will idle and pull
    up to around 1500~2000 rpm's (25 ~ 33 times a second input15 is being
    pulled high) but once i give it full thottle or 3/4''s thottle it
    will start to rev up then die and rev up and die, but i tried fooling
    around with the pulseout command to have it open up more to alow more
    fuel into the engine but for some reason still acts the same, am
    starting to think that ither the stamp isnt keeping up with magnetic
    pick up coil, or could i be over driveing the input coil with the
    engien rev'ing up so high it pulses to much current/voltage into the
    input15...... or is my stamp not being able to be triggered quickley
    enoguh so it can open injector and look back to it self once
    more .... ive heard from other people stamp 2 can only go so fast but
    i figure if im runing my engine with in 5000~6000 rpm range that it
    should be able to see the input pin, trigger the sub routine, read
    the thottle postion then do the lookup command for the correct pulse
    for the injector and loop back to its self agian....

    another question would be , in dealing with magnetic pick up coils
    and interfaceing them into the stamp, i probley need a better way to
    interface the two, in low rpm's it works fine but i have no idea how
    to tell if the stamp is realling reading every time the input is high
    then low agian or if its "skipping" sometimes across the coil
    pickup....

    also befor i forget... on the injector, i have a NPN power swithcing
    transistor to switch the state of the injector off/on , i have it
    setup where the base is pluged directly into the stamps output pin,
    the collector pluged into the ground and the emitter pluged into the
    injector and the other wire for injector is pluged into 12+ dc...


    hopefully someone can help me with this it sucks to see it my
    invention work but still have bugs in it... let me know what u guys
    think...

    Sean...




    '{$STAMP BS2}
    TB_POS VAR BYTE
    X VAR WORD
    x0 CON 1300
    x1 CON 1700
    x2 CON 2000
    x3 CON 3000
    x4 CON 4000
    x5 CON 4000
    x6 CON 5000
    x7 CON 6000
    x8 CON 8000
    x9 CON 10000
    x10 CON 12000
    x11 CON 13000
    x12 CON 14000

    MAIN:

    input 15

    IF IN15 = 1 THEN tb
    goto main

    TB:

    PULSIN 8, 1, TB_POS
    lookup TB_POS min 5 max 18 - 5,
    [noparse][[/noparse]x0,x1,x2,x3,x4,x5,x6,x7,x8,x9,x10,x11,x12], x
    pulsout 7,x
    GOTO MAIN


    **********end of programm


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