Fighting with computers

Computers are not always friendly.

Monday, March 01, 2010

On addressable RGB LEDs


I've been interested on the possible uses of RGB LEDs for quite a while. The underlying logic is pretty simple: Pulse Width Modulation can be used to control the luminosity of each color, giving as a result a similar system to how pixel color is controlled in any RGB display.

While creating a LED-based screen is possible and it's being done commercially, the size, power consumption and dot size make it only useful for large screens for sports or music events.

At a smaller scale this same technology seems cool for arts projects. The problem is that while many microcontrollers can do PWM, they have a limited number of outputs, and three of them are needed for each led.

Alternatively a matrix-like is possible for controlling arrays of RGB LEDs, but sacrificing its maximum luminosity.

Searching around the net several solutions pop up: serially addressable LEDs using one microcontroller for each LED, a serial-register-based RGB LED controller and an I2C-bus RGB LED controller.

2 Comments:

  • At 5:00 pm, Anonymous vierito5 said…

    www.hackaday.com is a great resource of POV (Persistence Of Vision) projects.

    Nice post!

     
  • At 5:10 pm, Blogger Miguel Sánchez said…

    Absolutely,

    Just have a look at:

    http://hackaday.com/2010/02/28/112-led-coffee-table/

    and this is just one of many projects there.

     

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