4 bit counter digital project

Discussion in 'The Projects Forum' started by mahmoudathab, May 20, 2011.

  1. mahmoudathab

    Thread Starter New Member

    May 20, 2011
    24
    0
    i have a problem with a 4 bit counter that counts from 0 to 9. i found the circuit in "digital fundamentals" by floyed and iam sure i connected everything right but the 7 sigment keep showing random numbers like 9,7,4,1,0 and other wierd figures so can someone please help me with this.
    here is the diagram from the book:
    http://imageshack.us/photo/my-images/827/unledyns.png/
    oh and i used 555 timer as astable multivibrator and set it to 1 hz.
     
  2. Xufyan

    Member

    Aug 3, 2010
    114
    0
    have you connected 7 Segment to 7447 IC properly ??

    see the attachments
     
  3. Georacer

    Moderator

    Nov 25, 2009
    5,142
    1,266
    Good point. 7-seg pin layout is tricky.

    You can troubleshoot your counter individually by sampling the output of the counter before you feed it into the 7447 IC. If you get a correct binary count (0000, 0001, 0010...) you problem probably lies within the 7447 circuitry.
     
  4. Wendy

    Moderator

    Mar 24, 2008
    20,765
    2,536
    Xufyan likes this.
  5. mahmoudathab

    Thread Starter New Member

    May 20, 2011
    24
    0
    thx alot guys the problem was with the 7-sigment connection:D
     
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