Timer

Archiver

How can I get an acurate measurement of time with the BS2. I am
trying to turn a relay on for a certain amount of time that the user
selects either by controlling a pot or pulsing an IO line. I can
think of some clumsy way of doing this through software, but I am
really looking for added hardware to the stamp such as a separate IC.


Thanks

Al Najjar

Archiver

When I need a fairly accurate timebase (real time, one second pulses)
and want to do it super-easy I go down Wal-Mart. (yikes) In the hobby
dept I pick up a clock movement. About 5 bucks. I open it up, remove
the mechanical stuff, snoop around where the coil was conected, and
find some nice, one second pulses. usually the movement will directly
drive an optoisolator.

If all you want is to control the "on" time of a relay a 555 might do
nicely. The 555 will source or sink 200ma, is easy to use, and may be
the only chip you need to accomplish what you'de like to do.

I look at it like this, a 555 costs about 1/100 the price of a BS2.

Regards

Rich
http://geocities.com/rbc1956


--- In basicstamps@y..., brownstamp@y... wrote:
> How can I get an acurate measurement of time with the BS2. I am
> trying to turn a relay on for a certain amount of time that the
user
> selects either by controlling a pot or pulsing an IO line. I can
> think of some clumsy way of doing this through software, but I am
> really looking for added hardware to the stamp such as a separate
IC.
>
>
> Thanks
>
> Al Najjar