Help with 7 segment LED

Discussion in 'The Projects Forum' started by snake126, Apr 1, 2011.

  1. snake126

    Thread Starter New Member

    Dec 15, 2010
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  2. SgtWookie

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    Jul 17, 2007
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    Just one? Or all 10?
     
  3. Wendy

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    Mar 24, 2008
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    It is a standard LED in a specialized package. Try using 1K resistors on the anodes and power it up with a 9V battery. There are chips meant to drive them (using resistors to prevent the chip and LED from burning out). Basically these chips convert BCD (binary coded decimal) to numbers for these displays.

    How much do you know about LEDs?
     
  4. SgtWookie

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    Just to throw an idea out there for the random patterns, an LFSR (linear feedback shift register) makes for a pretty good random pattern generator. You could use something like a 74HC595 shift register and some XOR gates for that part of the circuit.
    http://en.wikipedia.org/wiki/Linear_feedback_shift_register
     
  5. snake126

    Thread Starter New Member

    Dec 15, 2010
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    The more I think about it, it doesnt even have to change randomly. Is there a way to just be able to flip a switch, the display powers up and have it wired to show something that isnt a letter or number? something that could be percieved as "alien" is what I am getting at.

    If you could show me how to do this or point me in the right direction it would be awesome :)

    Thanks for your help
     
  6. k7elp60

    Senior Member

    Nov 4, 2008
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    Here is a circuit I designed a few years ago. You could change the individual LED's with a common anode display.
     
  7. Wendy

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  8. k7elp60

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    Nov 4, 2008
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    Snake126, Could you be more specific in the help you need. For example do you need help with getting the parts, placing the parts on a proto board, soldering etc.
    K7elp60
     
  9. SgtWookie

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    Just as an aside, it's usually easier to deal with common anode 7 segment displays rather than common cathode displays; as most drivers are designed to sink rather than source current. The displays you're looking at are common cathode.
     
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