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A Giant DIY LED Display

Posted by ryuzaki0 on from the cross-town-messaging-systems dept.

smf28 writes "Dheera Venkatraman has created a giant DIY LED display featuring 36 blue Luxeons in a 6x6 array on the windows of Simmons Hall, an undergraduate dormitory at MIT famous (or infamous, if you wish) for its design. Recent uses included welcoming students in September, Pirate Day, and others."

3 of 69 comments (clear)

  1. Blinkenlights? by Animaether · · Score: 4, Interesting

    http://www.blinkenlights.de/index.en.html

    And I *know* there was a Dutch team that did much the same as well, and a Dutch commercial venture (was it KPN - Dutch telecom?) has one still up and running, I think.

    But I guess they didn't use the Ooh! Shiny! blue LEDs :)

  2. Re:Circuit design error by dheera · · Score: 5, Interesting

    Thanks for the suggestions. The PIC should actually be able to drive the MOSFET, it's just that there ends up being some small amount of ringing, which then [in some way that I didn't bother to analyze] caused the entire thing to hang. Adding the resistors killed that and made it work especially for cases where a large fraction of the entire array is suddenly turned on. But yeah, redoing it with better power supplies and power circuitry would definitely be something to do when we get time. At the time it was built we were trying to finish as quickly as possible and used ATX power supplies which are essentially free at MIT (you find them lying around in dumped computers everywhere).

  3. Re:Slashdotted by dheera · · Score: 4, Interesting

    I looked at my logs. It's probably the initial rush of visits in the first couple of minutes. A potential "slashdotting-protection" system that could be implemented by large sites is to select different IP ranges at random and serve up the site with a 0, 30, 60, 90, 120, 150, or 180 second delay based on the incoming IP range (i.e. if you're in the IP range corresponding to the 120 second delay, the article doesn't even show up for you until 120 seconds after it has been posted. I don't know if this has other moral issues, or if it's Slashdot's responsibility to care, but it's just a thought about a hypothetical solution.