Monitoring software builds with a traffic light

[JD] at isotope11 was looking for a way to get instant feedback whenever a developer broke a piece of software they were working on. After finding a 48 inch tall traffic light, he knew what he had to do. Now, the entire development team knows the status of their code from a traffic light hanging in the corner.

isotope11 runs a continuous integration server to do the quality assurance on their software projects. It’s a lot more flexible than the ‘compile and pray’ setup we’re used to, but then again C isn’t very well suited to test-driven development. When one of [JD]‘s developers breaks a piece of code, the CI server will send a warning to an Arduino where all the electronic magic happens.

To light the traffic light, [JD] used a few relays to drive the 120 volt bulbs in the traffic light. The traffic light is very easy to read – red means something is broken, green means everything is alright, and yellow means a test suite is being run.

Check out the video of [JD]‘s TDD visualization after the break.


  1. jim says:

    um is that one of those hollywood filmset lights with different colours so it comes out normal in postproduction? am i stoned?

  2. Cristi Neagu says:

    You should have a big buzzer going off when a project fails.

  3. Munch says:

    C isn’t well-suited to TDD? What crack are you smoking? I’ve been doing TDD with C since 1998. C.f.

  4. Denbo says:

    Very cool project but tell the camera guy not to chew gum next time. Kind of a distraction

  5. blah says:

    Cool, but pointless, if you have that monitor showing the project red, the stop light is redundant lol.

  6. Josh Adams says:

    Josh from Isotope11 here. We do not always run the wall display on that monitor. Hence, !useless

  7. jim says:

    well, ok, but shirley something a but smaller would have done. maybe a little train that carries messages on its carriages?

    you could have it automatically order them in a shunting yard to construct sentences? i am sure this could work

  8. johndavid400 says:

    well… actually in the original design, there was no “Traffic light” there was a “Taser in your seat”, and anytime a developer broke a build – they would be the first to know it. But we soon realized that we would never have anyone deploy any code, so we went with “Traffic light”

  9. astro73 says:

    The local dev firm Atomic Object does this exactly. Except they’re a Ruby shop.

  10. N0LKK says:

    Only adults have to invent a reason to play, and justify it by making it look like the result is going to make things more productive. ;)

  11. xargle says:

    Gum chewing camera man is quite disgusting.

  12. Mike says:

    We did this with red and blue lava lamps at work.

  13. Tom Robinson says:
  14. Someone says:

    This is a pretty old thing.
    GitHub did this almost 2 years ago:

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