Specifications

BASIC Stamp II Application Notes

Parallax, Inc. • BASIC Stamp Programming Manual 1.8 • Page 345

Introduction. This application note shows how to use the new Xout

command to remotely control X-10

lamp and appliance modules.

Background. Home automation—the management of lights and ap-

pliances with a computer—promises to increase security, energy effi-

ciency, and convenience around the house. So why aren’t home-con-

trol systems more common? The answer is probably the wiring; it’s

hard to think of a nastier job than stringing control wiring through the

walls and crawlspaces of an existing home.

Fortunately, there’s a wireless solution for home control called X-10, a

family of control modules that respond to signals sent through existing

AC wiring. The BASIC Stamp II has the built-in ability to generate X-10

control signals with the new Xout instruction.

How it works. From the user’s standpoint, an X-10 system consists of

a control box plugged into a wall outlet, and a bunch of modules

plugged into outlets around the house. The appliances and lights to be

controlled are plugged into the modules.

During the installation of the system, the user assigns two codes to each

of the modules; a house code and a unit code. As the name suggests, the

house code is usually common to all modules in a particular house.

There are 16 house codes, assigned letters A through P. The idea of the

house code is to avoid interference between adjacent homes equipped

with X-10 by allowing the owners to assign different codes to their

modules. The control box must be assigned the same house codes as the

modules it will control.

There are also 16 unit codes (numbered 1 through 16) that identify the

modules within a particular house. If your needs expand beyond 16

modules, it’s generally safe to use another house code for the next group

of 16, since few if any neighborhoods are so infested with X-10 control-

lers that all available house codes are taken. X-10 signals don’t propa-

gate beyond the nearest utility transformer.

Once this simple setup is complete, the user controls the modules by

pressing keys on the control box. Pressing “1 ON” turns module 1 on.

1: X-10 Control