Showing service states on a traffic light

When I was about fifteen, I was an inveterate thief of temporary street furniture – no, I have no idea why. Hormones are funny things. Just in case anyone from Mid Beds County Council happens to be reading, I am very, very sorry. There were several bollards in my bedroom, a cat’s eye which my uncle (possibly while under the influence) had liberated from a street in the dead of night, and a no parking sign on the wardrobe door.

I never had a traffic light.

Raspberry Pi hooked up to a traffic light

♪ ♫ I like traffic lights, although my name’s not Bamber.

Magnus Lubeck has a traffic light (which he acquired through legal means), and he’s been using it – powered by a Raspberry Pi, of course – in place of a big display screen in his office for monitoring service states using Nagios/op5. Here’s some video.

There’s much more on Magnus’s blog, along with circuit diagrams and code, which you can use yourself if you happen to somehow come into possession of your own traffic light. He mentions the first application like this he ever saw, where a pub toilet lock was hooked up to a traffic light so you didn’t have to check whether there was someone in there or not. I’ve been thinking of ideas for this application from visual kitchen timers, to free parking space detectors, to instant message notifiers; although I feel it’s probably best not to get into the habit of using street furniture as interior decoration again. Add your own ideas below!