Home Hacking Projects for Geeks

17

2

I hate unlocking my front door in the dark. I’m never sure if I have the right

key in my hand, if it’s turned the right way, or where the keyhole is. The

worst part is that I have a porch light

right above the door. I can’t unlock

the door without the light, but I can’t get to the light without unlocking the

door. So, the light switch waits for me on the other side of the door, quietly

mocking me. I’ll teach that light to laugh at me.

From now on, porch light, I’m the boss, and these are the rules. You will:

• Turn on at dusk.

• Turn off at midnight.

• Turn on the entryway lights inside the house when someone approaches

the door after dusk but before midnight.

• Turn on both the porch light and the floodlights when someone

approaches the door between midnight and 6 A.M.

For the project to accomplish all this, we’ll need a logic mechanism that can

determine when to turn the lights on and off, and keep track of their state.

The logic mechanism will control the light switch and receive input from

a timer, motion detectors, and conventional light switches. You can buy

or build standalone logic mechanisms, but a computer is the simplest and

least expensive way to control everything. We’ll also need a light switch that

can be remotely controlled by the computer, and a motion detector that can

Automate Your

Porch Light

Cost

Time

Difficulty

$90

three hours

3 out ...