Easy $ 2 B made...

Discussion in 'The Projects Forum' started by matslapper, Oct 22, 2008.

  1. matslapper

    Thread Starter New Member

    Feb 25, 2008
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    I have unsuccessfully tried to build a modified version of LED roulette wheel. My problem is that I need to have only 18 LEDs on the board (most project kits have either 36 or 8) and be able to either switch that number of LEDs to 14 or have two separate circuits that would accomplish this goal. I know that this is a very simple circuit but I am running out of both time and patience. Someone can make some coin here if they can help me out.
     
  2. SgtWookie

    Expert

    Jul 17, 2007
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    Look at using CMOS 4017 Johnson counter IC's. You can cascade them. ONsemi's datasheet for the MC14017B shows a method for cascading them. Your project would require three 4017's, two AND gates, a clock circuit w/enable (could be built using a 4093, cap, resistor, switch) and a toggle switch to change the position of the reset line.

    You don't want an actual roulette wheel; you want it for randomly matching wrestlers in a varying number of sessions or something like that.
     
  3. matslapper

    Thread Starter New Member

    Feb 25, 2008
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    I can reconfigure the actual shape of the circuit (preferably two columns or rows) spaced evenly apart with enough space in between them to differentiate the two LED circuits and accompanying weight classes. I'm thinking something in the ball park of around 3" x 5" x 1". May need more room for battery? Point is, I need a novices schematic, real newbie here, to allow me to bread board this puppy and then start to design and layout a circuit board. Thanks
     
  4. SgtWookie

    Expert

    Jul 17, 2007
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    Actually - do you want individual LEDs, or do you want two 7-segment displays?

    The latter would be easier, require fewer components and less wiring.
     
  5. matslapper

    Thread Starter New Member

    Feb 25, 2008
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    Individual LEDs are what I'm looking for. Don't know how I would use the 7 segmented display.
     
  6. John P

    AAC Fanatic!

    Oct 14, 2008
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    So what is it that's really wanted here--is it a device with 2 columns of 9 LEDs each, and when you press and release a button, one randomly selected LED in each column lights up? That isn't a very difficult thing to design.

    Of course, 8 LEDs per column would be easier, but the real world is inconvenient.

    Edited to add the important words "randomly selected". You could base the selection on a very fast clock which runs as long as you hold the button down.
     
  7. matslapper

    Thread Starter New Member

    Feb 25, 2008
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    So, the number of LEDs is 14 one or two columns, as long as only one single LED is lit after a button is pushed or the timer is activated. The randomness(sp?) of the selection is the main point.
    Thanks again.
     
  8. scubasteve_911

    Senior Member

    Dec 27, 2007
    1,202
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    So who gets the 2 billion? John or Wookie?

    Steve
     
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