Hardware Hacking Projects for Geeks

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Chapter 9, How to Build a Cubicle Intrusion Detection System

11. Align the system

If you are using the Radio Shack entry alert product, set it up in the door-

way of the cube you want “protected.” The kit includes a red reflector and

instructions on setup.

If you are setting up the laser-based version, mount the main project

enclosure so that the laser will fire across the opening of the cube or office

you want protected. Mount it with tie wraps, metal coat hangers, or even

Velcro. Power it on and look to see where the laser places its dot. Take a

small mirror and secure it with double-sided foam tape or other adhesive so

that it reflects the dot back at the main enclosure. Use the laser pivot mount

to point the laser so that it hits the photo-detector assembly. When properly

aligned, the LED on the board will switch off. It will switch on when the

beam is interrupted. Multiple mirrors may be used to cover a larger area.

The LED laser should be able to project a beam over 50 feet.

Finally, attach the “warning” LED cable assembly to the circuit board and

check that it switches on when someone breaks the beam. Place it so that it

is inside your field of vision when you are working.

Project Demo

After you have aligned the laser or entry alert box and set the warning LED

on your desk so that you can see it, call a few fellow office workers and ask

them to step in to your cubicl