Running a transistor while doing other things....

Archiver

Hi all!

I have a situation in which I need my stamp to go high on a pin to
the base of a transistor (or possibly relay... read on) to control a
12V supply to a solinoid. The solinoid needs to stay open for a fixed
amount of time (half a second or so), but this is done for several
solinoids, and I am also outputting a continutious reading to a LCD.
The problem is that by doing:

solinoid1:
high 7
pause 500
low 7
RETURN

solinoid2:
high 8
pause 500
low 8
RETURN

ETC>..
It may be a few seconds before the lcd is updated, which, for this
application, is neccessary (if for no other reason than to be not
annoying)

How is this usually handled? Ideally the stamp would just go high to
another curcuit for a few ms, and that circuit is timed somehow. A
555 timer that is reset by a pin on the stamp? I have never used a
555 before, so I'm not sure if that's the way to go or not.

Thanks for any help!

Archiver

One way would be to set up a counter in the program,whenever the counter
reaches a certain count a relay is turned on, when it reaches another
count it turns a relay off
You would have to experiment to get the timeing correct


On Wed, 28 Nov 2001 00:07:23 -0000 nospam@e... writes:
> Hi all!
>
> I have a situation in which I need my stamp to go high on a pin to
> the base of a transistor (or possibly relay... read on) to control a
>
> 12V supply to a solinoid. The solinoid needs to stay open for a
> fixed
> amount of time (half a second or so), but this is done for several
> solinoids, and I am also outputting a continutious reading to a LCD.
>
> The problem is that by doing:
>
> solinoid1:
> high 7
> pause 500
> low 7
> RETURN
>
> solinoid2:
> high 8
> pause 500
> low 8
> RETURN
>
> ETC>..
> It may be a few seconds before the lcd is updated, which, for this
> application, is neccessary (if for no other reason than to be not
> annoying)
>
> How is this usually handled? Ideally the stamp would just go high to
>
> another curcuit for a few ms, and that circuit is timed somehow. A
> 555 timer that is reset by a pin on the stamp? I have never used a
> 555 before, so I'm not sure if that's the way to go or not.
>
> Thanks for any help!
>
>
>
>
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Archiver

Here is a possibility for you.

Solenoid var byte
LCD var byte

For Solenoid=1 to 8
High solenoid
For LCD=1 to 10 'loop size & pause to match timing
'update LCD here
'pause if needed
Next
Low solenoid
next

If each solenoid had a different time, you could make a lookup table
with the appropriate pause values to match. For the example I just
assumed outputs 1 through 8. Change accordingly.

Lee Harker


--- In basicstamps@y..., nospam@e... wrote:
> Hi all!
>
> I have a situation in which I need my stamp to go high on a pin to
> the base of a transistor (or possibly relay... read on) to control
a
> 12V supply to a solinoid. The solinoid needs to stay open for a
fixed
> amount of time (half a second or so), but this is done for several
> solinoids, and I am also outputting a continutious reading to a
LCD.

> The problem is that by doing:
>
> solinoid1:
> high 7
> pause 500
> low 7
> RETURN
>
> solinoid2:
> high 8
> pause 500
> low 8
> RETURN
>
> ETC>..
> It may be a few seconds before the lcd is updated, which, for this
> application, is neccessary (if for no other reason than to be not
> annoying)
>
> How is this usually handled? Ideally the stamp would just go high
to
> another curcuit for a few ms, and that circuit is timed somehow. A
> 555 timer that is reset by a pin on the stamp? I have never used a
> 555 before, so I'm not sure if that's the way to go or not.
>
> Thanks for any help!