Programming the Integrated House: Code Versus Volts
The integrated house, also known as the automated house, is one in which all appliances and amenities of the residence are controlled automatically from a master command center. Activities such as turning lights on and off, arming the security system, turning on lawn sprinklers, closing and opening window draperies, operating a home entertainment center, and turning on the coffee pot are handled by a central device.
In the days before computer technology, remote appliance control was exercised by flicking switches on the wall or in a sofa-side control bank, just like you saw in James Bond movies or read about in Playboy. With the advent of the PC and PDA, such control has been relegated to touch screens and mouse clicks.
When I first went in search of the wired kitchen, my thinking was that the current state of the art had produced a plethora of digitally enabled household devices and appliances that were easy to set up and easy to program.
I was wrong.
According to my home electronics expert, Tony Gregg at Capitol Electronics in Culver City, California, there isn't any plug-and-play: Home automation is all system engineered.
I was very disappointed that learn that there aren't any Java-enabled ovens and no .NET dishwashers. I thought that automating a home should be no more effort than installing the devices and writing code to the devices!
Just as I can write this Java code to run a printer:
I thought that I could write this code to run an oven:
I was wrong. It turns out that automating the home is more a case of pushing volts rather than writing code.
Allow me to elaborate.
The present state of home automation electronics is this simple: A device is either on or off. That's what you get to control: on and off. And, in the case of lighting, you can control how much "on" a device is, in terms of dimness or brightness. The ability to actually go into a device programmatically and play with its innards is still a technology in its infancy. Kitchen automation technology doesn't really allow you to set your microwave to defrost and turn your oven to 450 degrees using your cell phone. You can use your cell phone to turn the power to the microwave on or off. Or you can use your cell phone to turn the power on to the lawn sprinklers in your garden. But operations beyond simple power on, power off are just not there yet.
Figure 1 shows a conceptual schematic of a home automation system. The fundamentals are simple. Power runs from the main power source to a home automation controller box (1). Inside the box are "on and off" switches and dimmers. These are connected to a processor that controls their activity. The power lines for the various devices and appliances running under home automation are connected to the switches and dimmers inside the box (2). To program the processor inside the home automation controller box, you use a standard wall keypad, a cell phone that calls a modem connected to the home automation controller box, or a PC connected to the box via serial connection (3). The programmed processor then implicitly controls the power lines to the various appliances and amenities in the house.
Figure 1 A conceptual schematic of a home automation system.
The I/O for the processor is quite simple. Whether you're using a wall-type security keypad, a cell phone, or a high-end HTML touch screen to input data, behind it all you're moving is bits in the form of character strings. For example, if you tap #011845 into a keypad, the system might turn on light #1 at 6:45 PM (if the system interprets the string #011845 this wayhome automation protocols are highly proprietary). Instructions and setting values vary from system to system. As I was told by Randy Bush, my technical contact at Vantage Controls, a leading manufacturer of home automation equipment, all he really needs to control any Vantage home automation system is a copy of HyperTerminal running on Windows, and a serial port.