need a one second timer
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Hi David! I've tryed with 555 but beleave me it is not stable and reliable at
all!
Your best way is to use a 32.768 Khz with a CD4060 as explained on the
book of Scott Edwards about programming stamp. It is on the time/temperature
display experiment. It give you a 2 Hz pulse which still can divide by your
stamp
simply by using a "flag"
Have fun!
Rene
David Kissick a
all!
Your best way is to use a 32.768 Khz with a CD4060 as explained on the
book of Scott Edwards about programming stamp. It is on the time/temperature
display experiment. It give you a 2 Hz pulse which still can divide by your
stamp
simply by using a "flag"
Have fun!
Rene
David Kissick a
Comments
I need to know how to make an accurate one second timer (1 Hz
pulse) that the stamp can use as a timing function. One design uses a
555 timer to output at 1 Hz, but I need something a little more
reliable and stable. I'm sure a crystal is needed, but due to my lack
of electronic knowledge, I'm not sure how to implement one into a
design. This should be easy to answer (I hope), but would be a great
help to me. Thanks!
David
that uses a 4060 IC and a 32,766 Hz crystal. It gives
you an accurate 2 tick-per-second output for the
Stamp. I have used one for a small 15 minute timer
with great success.
--- Original Message ---
> I need to know how to make an accurate one second
timer (1 Hz
>pulse) that the stamp can use as a timing function.
One design uses a
>555 timer to output at 1 Hz, but I need something a
little more
>reliable and stable. I'm sure a crystal is needed,
but due to my lack
>of electronic knowledge, I'm not sure how to
implement one into a
>design. This should be easy to answer (I hope), but
would be a great
>help to me.
http://www.parallax.com/dl/docs/cols/nv/vol1/col/11.pdf
-- Jon Williams
-- Parallax
Original Message
From: daweasel@s... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=SJZbax6W4QwEFVJhoymIHZgLoauPxKwV3zmbgfzX7lkXJhd3lglYPW-yM7q9GtGmoIFEgyi2f3LVUxU]daweasel@s...[/url
Sent: Wednesday, January 07, 2004 5:30 PM
To: basicstamps@yahoogroups.com
Subject: Re: [noparse][[/noparse]basicstamps] need a one second timer
In one of the early N&V columns there is a BS1 project
that uses a 4060 IC and a 32,766 Hz crystal. It gives
you an accurate 2 tick-per-second output for the
Stamp. I have used one for a small 15 minute timer
with great success.
--- Original Message ---
> I need to know how to make an accurate one second
timer (1 Hz
>pulse) that the stamp can use as a timing function.
One design uses a
>555 timer to output at 1 Hz, but I need something a
little more
>reliable and stable. I'm sure a crystal is needed,
but due to my lack
>of electronic knowledge, I'm not sure how to
implement one into a
>design. This should be easy to answer (I hope), but
would be a great
>help to me.
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can be had from the cheapest of AA powered alarm clocks. Sometimes
found in 'dollar' stores, or yard sales.
>In one of the early N&V columns there is a BS1 project
>that uses a 4060 IC and a 32,766 Hz crystal. It gives
>you an accurate 2 tick-per-second output for the
>Stamp. I have used one for a small 15 minute timer
>with great success.
>
><http://www.parallax.com/dl/docs/cols/nv/vol1/col/11.pdf>
--
Chuck Britton Education is what is left when
britton@n... you have forgotten everything
North Carolina School of Science & Math you learned in school.
(919) 416-2762 Albert Einstein, 1936
> I need to know how to make an accurate one second timer (1 Hz
>pulse) that the stamp can use as a timing function. One design uses a
>555 timer to output at 1 Hz, but I need something a little more
>reliable and stable. I'm sure a crystal is needed, but due to my lack
>of electronic knowledge, I'm not sure how to implement one into a
>design. This should be easy to answer (I hope), but would be a great
>help to me. Thanks!
>
>David
Several of the 8-pin real time clock chips also have a pin with 1 hz
output. E.g., the Dallas DS1307 or the Philips PCF8583.
David
--- In basicstamps@yahoogroups.com, "Jon Williams" <jwilliams@p...> wrote:
> Here's the column in a PDF reprint:
>
> http://www.parallax.com/dl/docs/cols/nv/vol1/col/11.pdf
>
> -- Jon Williams
> -- Parallax
other features, servo controllers, A/D etc.
http://www.bluebelldesign.com/Co_Proc_Detail1.htm
It also comes with a pcb as part of a kit
http://www.bluebelldesign.com/CoP_Bd.htm
or as part of a PCB with a Stamp 2p40 processor built in.
http://www.bluebelldesign.com/Bot_Pics.htm
We use a crystal so it is very accurate. The timers can be set in
steps of 20 ms. At the end of the timing interval a "timers finished"
line goes high. You can look for this line with a Stamp input.
Reading a status byte will reset the line and tell you which timer(s)
finished since the last time you read it.
One of the timers can be set to restart automatically. This is good
for keeping time of day type things. Otherwise the time you take to
reset the timer each time will accumulate for a bigger error.
You said you cared about the one second being very accurate. BASIC
Stamps have no interrupts so you can't do much while looking for the
timer to finish. You could set another timer to "warn" the Stamp to
be looking out for the 1 second timer that you want. That way it can
run other code for most of the 1 second period. Check periodically
for the "warning" timer to finish. When it is done, you can go into a
tight loop just looking for the timer complete signal to tell you the
one second time is up.
You could also periodically read the time left in the one second
timer. When it is close to done, switch to the higher speed loop.
Harry
Stamp Robotics to the next level
www.bluebelldesign.com
--- In basicstamps@yahoogroups.com, "David Kissick" <geckoinc99@y...>
wrote:
> Hey everyone,
> I need to know how to make an accurate one second timer (1 Hz
> pulse) that the stamp can use as a timing function. One design
uses a
> 555 timer to output at 1 Hz, but I need something a little more
> reliable and stable. I'm sure a crystal is needed, but due to my
lack
> of electronic knowledge, I'm not sure how to implement one into a
> design. This should be easy to answer (I hope), but would be a
great
> help to me. Thanks!
>
> David