One afternoon, as I was just hanging out at the local hackerspace, an old friend who collected traffic lights contacted me. Turns out his new girlfriend wasn't a fan of having a pile of traffic lights in their apartment, and he was looking to get rid of a couple to a good home. Knowing I spent an unhealthy amount of time at a hackerspace, he figured I'd be able to take one off his hands. What kind of self-respecting nerd would I be if I hadn't taken him up on his offer?
A couple of days laterhe dropped by with a traffic light, bulbs and all. I took it to the local hackerspace and pulled it open. All the insides had been removed, except for the wires running to each socket, but the actual system looked like it was ready to go. After a little bit of testing, all the sockets and bulbs had been verified to work, although having one light on in a 3 light traffic light is almost as good as it not having any lights on at all. No geek cred for that.
I'd never worked with this before, so I went and researched ways to turn on a lightbulb using an arduino, bought a couple of the Beefcake relays from sparkfun and started planning.
Acutally putting the thing together was fairly easy. We've added a switch so we can make it be the start signal for the robot fights at the hacker space, and the beefcake relays are basically the only moving parts. The thing was assembled at a local maker faire as an example of a project being worked on live, which is why we used cardboard (what we had on hand) as an insulator for all of the electrical parts from the metal body of the traffic light.
There's also an Ethernet module in there, just in case later I want to add in ethernet capacity for doing something like testing the hackerspace's network for outages.