Turn on a led for two minutes each 13 minutes all day long(...

Archiver

The BS2 uses a ceramic resonator for timing which is close, but not perfect
or as accurate as a crystal. Temperature can affect timing. I'm betting
that part of your problem is in your loops to create long delays. You must
account for this overhead otherwise your timing will run long.

-- Jon Williams
-- Parallax

In a message dated 4/26/2003 5:30:44 PM Central Standard Time,
joeterk@y... writes:

> Hi,
> I am tring to use the BS2 to turn on a led during
> 15 minute (2 minutes on and 13 minutes off) all
> day long using a simple code (with pauses, low,
> high...comands)
>
> I started at 13:00:00 but, four hours later
> the led turn on at 13:00:05 (5 seconds later)
>
> I thought that BS2 is exact. But I can't use
> it like a clock.
>
> Thanks, Joe
>



[noparse][[/noparse]Non-text portions of this message have been removed]

Archiver

Thanks Jon:
Do you think that the solution could
be add a 555 or a real time clock?

Thanks in advance: Joe

--- jonwms@a... wrote:
> The BS2 uses a ceramic resonator for timing which is
> close, but not perfect
> or as accurate as a crystal. Temperature can affect
> timing. I'm betting
> that part of your problem is in your loops to create
> long delays. You must
> account for this overhead otherwise your timing will
> run long.
>
> -- Jon Williams
> -- Parallax
>
> In a message dated 4/26/2003 5:30:44 PM Central
> Standard Time,
> joeterk@y... writes:
>
> > Hi,
> > I am tring to use the BS2 to turn on a led during
> > 15 minute (2 minutes on and 13 minutes off) all
> > day long using a simple code (with pauses, low,
> > high...comands)
> >
> > I started at 13:00:00 but, four hours later
> > the led turn on at 13:00:05 (5 seconds later)
> >
> > I thought that BS2 is exact. But I can't use
> > it like a clock.
> >
> > Thanks, Joe
> >
>
>
>
> [noparse][[/noparse]Non-text portions of this message have been
> removed]
>
>
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Archiver

You're kidding about the 555, right? Vis-a-vis the 555, the BASIC Stamp
looks like an atomic clock! Use an external RTC. I am personally partial to
the PCF8583 (I2C). You can find code for the PCF8583 and the DS1302 on our
web site.

-- Jon Williams
-- Parallax


In a message dated 4/26/2003 8:54:22 PM Central Standard Time,
joeterk@y... writes:

> Thanks Jon:
> Do you think that the solution could
> be add a 555 or a real time clock?



[noparse][[/noparse]Non-text portions of this message have been removed]

Archiver

Nuts & Volts column #11.

---

Original Message

---

> Do you think that the solution could
> be add a 555 or a real time clock?

> > The BS2 uses a ceramic resonator for timing which is
> > close, but not perfect
> > or as accurate as a crystal. Temperature can affect
> > timing. I'm betting
> > that part of your problem is in your loops to create
> > long delays. You must
> > account for this overhead otherwise your timing will
> > run long.

> > > I am tring to use the BS2 to turn on a led during
> > > 15 minute (2 minutes on and 13 minutes off) all
> > > day long using a simple code (with pauses, low,
> > > high...comands)
> > >
> > > I started at 13:00:00 but, four hours later
> > > the led turn on at 13:00:05 (5 seconds later)
> > >
> > > I thought that BS2 is exact. But I can't use
> > > it like a clock.