[GRLUG] Time Clocks and Software

[L. V. Lammert]

On Wed, 26 Jan 2011, Ben Rousch wrote:

> > An arduino with a 'buzzer file' on an SD card, solid state relay, and DS1307
> > RTC would allow you to replace the timeclock relay without needing a
> > computer to plug a usb relay into.
> >
> This is more along the lines of what I thought people would suggest.
> Very interesting. My major concern with this is clock drift. Ideally
> the clock needs to be correct to within a few seconds, or I need to be
> able to regularly correct time via something like NTP. Also I have no
> experience with Arduino, so there would be a learning curve.
>
Your 'server' would maintain the master clock - the Arduino's would just
get the Ethernet 'relays' to sound the buzzers.

Check out emacinc.com - local Illinois company specializing in Linux SBCs
and I/O.

> I've just started looking into plug computers, like the SheevePlug. A
> Linux install on a wall wart, with a USB port. Maybe I can plug in one
> of the previously-suggested USB relays and create a fairly simple
> system. http://en.wikipedia.org/wiki/SheevaPlug
>
Another good option. Be a little careful, however, some of these wouldn't
survive a manufacturing environment.

The cost might be a tad higher, but for a harsh environment you can't beat
a simple Adam module - Ethernet, RS232, or RS45 on one side, I/O point on
the other [to drive a relay]. B&B or Advantech.

	Lee

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