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make a stamp kill power to itself? — Parallax Forums

make a stamp kill power to itself?

ArchiverArchiver Posts: 46,084
edited 2001-03-25 04:42 in General Discussion
Does anyone know how I can make a stamp kill power to itself. I'm
not quite sure what the outcome of this is going to be.

When started my program does a series of things, watches buttons in a
loop, and when a certain pin goes low, I want the stamp to stop
working. I don't want it in "end" mode, I want to disconnect it from
power completely.

Here's my pseudocode:
main:
do stuff
loop:
if button 1 goto shutdown
if button 2 something else
goto loop

shutdown:
<--- what to do here???



should i trigger a relay that would open the contacts and thus kill
power to the stamp here?


My application is such that when the car accessory line goes high,
the stamp turns on and does stuff; when the car accessory line goes
low, I want the stamp to turn off and draw NO power from the battery.
Next time the car is started, do the same, repeat, lather, rinse,
etc...


Is my program logic bad or can i put a relay/capacitor on the stamps
power line and when it shuts down, trigger the relay (which opens the
contacts) and thus takes power away from the stamp? Would this work
r would it produce strange results?!?

Any help on this would be greatly appreciated...!

-Chris

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2001-03-25 03:49
    Just run the stamp from the accessory line, or have a relay (driven from the
    accessory line) switch the stamp on and off.

    -Rob


    Original Message
    From: <christopher_bergeron@y...>
    To: <basicstamps@yahoogroups.com>
    Sent: Saturday, March 24, 2001 8:50 PM
    Subject: [noparse][[/noparse]basicstamps] make a stamp kill power to itself?


    > Does anyone know how I can make a stamp kill power to itself. I'm
    > not quite sure what the outcome of this is going to be.
    >
    > When started my program does a series of things, watches buttons in a
    > loop, and when a certain pin goes low, I want the stamp to stop
    > working. I don't want it in "end" mode, I want to disconnect it from
    > power completely.
    >
    > Here's my pseudocode:
    > main:
    > do stuff
    > loop:
    > if button 1 goto shutdown
    > if button 2 something else
    > goto loop
    >
    > shutdown:
    > <--- what to do here???
    >
    >
    >
    > should i trigger a relay that would open the contacts and thus kill
    > power to the stamp here?
    >
    >
    > My application is such that when the car accessory line goes high,
    > the stamp turns on and does stuff; when the car accessory line goes
    > low, I want the stamp to turn off and draw NO power from the battery.
    > Next time the car is started, do the same, repeat, lather, rinse,
    > etc...
    >
    >
    > Is my program logic bad or can i put a relay/capacitor on the stamps
    > power line and when it shuts down, trigger the relay (which opens the
    > contacts) and thus takes power away from the stamp? Would this work
    > r would it produce strange results?!?
    >
    > Any help on this would be greatly appreciated...!
    >
    > -Chris
    >
    >
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2001-03-25 04:33
    If the ports normally start up in a low state, you could set up a relay to
    break the power connection when a specific port goes high.

    Original Message

    > How about holding a transistor to the supply on via holding a voltage on
    an
    > IO pin. When you change the value of the IO pin to low the transistor
    shuts
    > off killing the power to the stamp (hence the IO line remains low). The
    > problem with this aproach would be turning it on again as the stamp would
    > have to be running to initialize that line high. just a thought and
    > probably not an all that good one. I like the relay idea better myself
    but
    > I took all this time to write this so ill send it anyway lol.
  • ArchiverArchiver Posts: 46,084
    edited 2001-03-25 04:41
    Why not just put the stamp to sleep when it's not needed? it seems at the
    nominal sleep current of 25 microamps, it would be basically invisable to
    the car battery....
    fwiw
    Steve



    At 09:33 PM 03/24/2001 -0600, you wrote:
    >If the ports normally start up in a low state, you could set up a relay to
    >break the power connection when a specific port goes high.
    >
    >
    Original Message
    >
    >> How about holding a transistor to the supply on via holding a voltage on
    >an
    >> IO pin. When you change the value of the IO pin to low the transistor
    >shuts
    >> off killing the power to the stamp (hence the IO line remains low). The
    >> problem with this aproach would be turning it on again as the stamp would
    >> have to be running to initialize that line high. just a thought and
    >> probably not an all that good one. I like the relay idea better myself
    >but
    >> I took all this time to write this so ill send it anyway lol.
    >
    >
    >
    >
    >
    >
    >Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2001-03-25 04:42
    How about holding a transistor to the supply on via holding a voltage on an
    IO pin. When you change the value of the IO pin to low the transistor shuts
    off killing the power to the stamp (hence the IO line remains low). The
    problem with this aproach would be turning it on again as the stamp would
    have to be running to initialize that line high. just a thought and
    probably not an all that good one. I like the relay idea better myself but
    I took all this time to write this so ill send it anyway lol.


    Original Message
    From: <christopher_bergeron@y...>
    To: <basicstamps@yahoogroups.com>
    Sent: Saturday, March 24, 2001 8:50 PM
    Subject: [noparse][[/noparse]basicstamps] make a stamp kill power to itself?


    > Does anyone know how I can make a stamp kill power to itself. I'm
    > not quite sure what the outcome of this is going to be.
    >
    > When started my program does a series of things, watches buttons in a
    > loop, and when a certain pin goes low, I want the stamp to stop
    > working. I don't want it in "end" mode, I want to disconnect it from
    > power completely.
    >
    > Here's my pseudocode:
    > main:
    > do stuff
    > loop:
    > if button 1 goto shutdown
    > if button 2 something else
    > goto loop
    >
    > shutdown:
    > <--- what to do here???
    >
    >
    >
    > should i trigger a relay that would open the contacts and thus kill
    > power to the stamp here?
    >
    >
    > My application is such that when the car accessory line goes high,
    > the stamp turns on and does stuff; when the car accessory line goes
    > low, I want the stamp to turn off and draw NO power from the battery.
    > Next time the car is started, do the same, repeat, lather, rinse,
    > etc...
    >
    >
    > Is my program logic bad or can i put a relay/capacitor on the stamps
    > power line and when it shuts down, trigger the relay (which opens the
    > contacts) and thus takes power away from the stamp? Would this work
    > r would it produce strange results?!?
    >
    > Any help on this would be greatly appreciated...!
    >
    > -Chris
    >
    >
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
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