Hardware Hacking Projects for Geeks

179

9

9. How to Build a

Cubicle Intrusion

Detection System

Cost

Time

Difficulty

$100

a weekend

difficult

One of the first jobs I had out of college was at Apple Computer. My office

was on a huge open floor that had been partitioned into cubicles.

The work I did at Apple involved some level of concentration, and the

sounds from others in adjacent cubes would often distract me. To combat

these distractions, I would wear a set of headphones to block out external

noise. Unfortunately, a new problem soon became apparent: I could not tell

when someone had come into my cube to ask me a question. The person in

the cube next to mine had the endearing habit of sneaking up behind me

and either grabbing my shoulders or tossing a ball of paper at me. I would,

of course, jump when startled in this way, and it invariably ruined my con-

centration for several minutes.

I decided to solve this new problem with a quick hardware hack. I built a

“cubicle intrusion detector” using a laser pointer, a BasicStamp2 (a com-

plete microcontroller you program using a version of the BASIC language),

and a photo-detector. The system worked by shining the light from the laser

pointer onto a photo-detector connected to a microcontroller. I directed

the laser light across the entrance to my cubicle and, using a small mirror,

reflected it back at the photo-detector so that the beam would be broken if