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More about How it all Works

One of the best treats you have in store is the fact that this technology
is already well developed and hundreds of products exist from which you
can choose and tailor your own system.

The idea is simple: messages are sent throughout your house using your
existing house electric wiring !

If you're building a new home you can also delight in planning for lots of built-ins.
Simple devices are available which allow you to either plug-in, build-in, or both !

Each of the 'things' that you want to control, like lamps and appliances,
simply plug in to a 'module' which looks like this :

Lamp Module
There are two different types of module, one for lamps which you can dim, and one for appliances which you just turn on and off. There are also some special modules for things like hot water heaters etc.

These modules have two dials on the front which are used to set the 'address' for each of the lamps and appliances.

There are 16 different 'House' letters, and 16 different 'unit' numbers. This is where you have to use a screwdriver !

You'll see one or both of these little dials on all products which work with your Mac system.

You have the choice of 256 different addresses, you can use them all, but it's unlikely that you will need but a few at first.

You simply set each module to a unique 'address' this one is: A1

Back at the Macintosh:

Just as you would have to instruct a servant in the proper names of each
of the lamps and appliances in your home, you must tell your Mac about these
devices, and what their names and addresses are.

There also needs to be a connection between your Mac and your house power
lines so that it can talk to your lamps and appliances.

This is another little box which plugs in to a wall socket, and also has
a cable that plugs into your Mac's serial port.

This 'interface' is about the size of the lamp module above, and knows how to send and receive signals back and forth between your power lines and the Macintosh :

Simple Connection
A Mac, and a cable
to the

...which is plugged into a wall socket.

and a "Bed Lamp" which is
plugged into a lamp module,
which is also plugged into
your house wiring.

With a screwdriver, set the address
of the lamp module to A5,

You tell your Mac that "Bed Lamp" has address A5, and from then on, it knows
what you mean when you tell it to :
turn on "Bed Lamp"

( Oh, yes, the normal power cable for the Mac is not shown ).

If you extend this idea to several lamps, the coffee pot, and the outside lights, you can see that each thing that you want to control needs its own 'module', and each must have its own address and unique name.

You will want to be able to 'dim' some of these lamps to a certain level as well as turn them on and off.

The standard lamp module will allow you to set the brightness between zero and 100. like: dim "Bed Lamp" to 50

Because your Mac knows what time it is and even things like when the sun will rise today, you can tell it to brighten the "Bed Lamp" to 50% at 7AM each weekday and turn it gently off at 9AM after you're gone.

On the weekends, you can have the Mac wake you just at sunrise for your jog.

Things like the curlers and the coffee pot cannot be dimmed and brightened, and you simply tell the Mac that they can only be turned on and off.

Now that your Mac has learned how to control all of these things, you have to tell it more about your personal schedule, and such things as when to turn the sprinklers on, and of course not if it's raining.

OH ! but how does the Mac tell whether it's raining ?

Your Mac can both send messages and receive them ! From where?

There are more goodies that you will really love :

OK, I want to know more :

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The house talks back !

Copyright 2007, Sand Hill Engineering All rights reserved.

Mac Made

Last modified: May 1, 2002
Michael Ferguson, webmaster@shed.com