Interactive Christmas Tree

Discussion in 'The Projects Forum' started by Genoil, Nov 1, 2012.

  1. Genoil

    Thread Starter New Member

    Aug 5, 2011

    I want to build an interactive christmas tree where I can precisely control which light is on or off. In order to keep the number of wires limited, I thought of a solution where each led has its own I2C enabled PIC operating in slave mode, with an additional master PIC that is programmed to tell which slave to enable or disable. A 4-wire cable would then be sufficient. Nevertheless it sounds a bit too complex...

    The actual logic that I need is also a bit more simple. Instead of controlling each light individually, it would suffice to interactively increment the number of leds that are on. So first LED 1 is on, next step is 1 and 2, then 1, 2 and 3 and so on.

    My knowledge of electronics is a bit limited, so I wonder if anybody over here has some illuminating ideas...
  2. MrChips


    Oct 2, 2009
    Controlling a single LED from a PIC would be a horrific mess and very wasteful of resources.

    A better solution would be to control eight LEDs from one low pin count chip and networking all chips from a master controller.

    Another solution would be to drive eight LEDs from a serial shift register and daisy chain as many shift registers you wish controlled by one MCU. This would be your simplest solution.
  3. Genoil

    Thread Starter New Member

    Aug 5, 2011

    Yes of course I could add multiple LEDs to each PIC, it would actually safe me a lot of wire (and PICs!)

    I'll look into these serial shift registers. They sound cheaper than PICs, for one :)
  4. crutschow


    Mar 14, 2008
  5. n1ist

    Senior Member

    Mar 8, 2009
  6. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    Last year or so I believe one company came out with individually addressable string of Christmas LED bulbs. I don't remember the interface details but it's all online.

    Target already has their Christmas stuff up and I believe these LEDs are on display. Get the name and google it and you'll get the details.

    I'd help start you but I'm three states from home as a powerless hurricane refugee.