Re: Home Automation with GS

[adrianw@cassius.ee.usyd.edu.au (Adrian Whichello)]

In article <33ee0725.6356630@nntp.ix.netcom.com>,
Vince Scoglietti <vcs@ix.netcom.com> wrote:
>Hello,
>	I just read the home automation with a PC parallel port
>article in the September issue of Popular Electronics.......in the
>article, there are plans for a PC parallel port controlled board with
>8 relays that switch 120 volt AC on/off.  The idea is to set up an old
>PC AT/XT with this board, and have it turn on lights, heaters, etc. at
>specific times of the day.  The PC issues a hex byte out of the
>paralle port, and each of the 8 bits turns a relay on or off (you also
>have to build a parallel cable with the appropriate resistors in line
>to avoid frying things).   Anyway, I don't have a spare AT or XT, but
>I was wondering if I could use the modem port on the back of my IIGS
>(which doesn't get much use nowadays). I realize that this is a serial
>port, which would fundamentally change the hex byte operation, but
>it'd be cool even if I only had one relay wired.  Anyone have any
>information, stories, etc?  I'd especially like pinouts of the port, a
>routine to read the GS clock from Applesoft, and the POKE's that
>operate the serial ports.

A lot more work than just using the game io port on an apple, but certainly
possible. Many hobbyist electronics magazines have published the sort of
article you want; I know our local ones (Silcon Chip and Electronics Australia)
do it on a regular basis (and you thought only women's magazines recycled their
articles!).

>
>	Also, does anyone control model trains from their Apple?

Yes.

>  I
>think it'd be cool to switch operating lights on/off, semafores, and
>perhaps a Apple controlled variable potentiometer for throttle?
>That's a stretch (I'm utterly clueless on this one), but novel
>anyways.
>

Not really. You only need a cheap digital to analogue converter chip and a
power transistor. A jerky controller (16 levels) could be built using the games
port, or a smoother one (256 levels) using a parallel printer interface.  But
there's a big movement to do amazing computer control with "DCC" (Digital
Command Control" - go ask in rec.models.railroad), with tiny decoders in the
locomotives. Or for a different approach, get Bruce Chubbs book "Building a
Universal Computer Interface" (I think).

--
Dr Adrian Whichello                                  Phone: +61 2 9351 5339
Imaging Science and Engineering Laboratory             Fax: +61 2 9351 3847
Sydney University Electrical Engineering      Email: adrianw@ee.usyd.edu.au
Australia                           WWW: http://www.ee.usyd.edu.au/~adrianw

"I wish to God these calculations had been executed by steam!" - C. Babbage