Can I use shift register??

Discussion in 'The Projects Forum' started by Digital Design, Feb 27, 2009.

  1. Digital Design

    Thread Starter New Member

    Feb 22, 2009
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    Hi all,
    Need help with this table. I would like to build circuit with this.
    Can I use a shift register to input the binary format and get the output?
    I need to use a 1-bit DIP switch and input Display with a PB switch coupled to a pulser circuit.
    What can I do to achieve that?
     
  2. thingmaker3

    Retired Moderator

    May 16, 2005
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  3. Digital Design

    Thread Starter New Member

    Feb 22, 2009
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    But i need to keep store the values and keep descending the number from 10 to 0..if NAND gates, will it not possible to store the values?

    Thank you
     
  4. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    Assuming the "Display" part is already completed (via 7 Segment driver?):
    Use SR latches to the LEDs, and buffer the high 7 bits to the reset of the latches for the "up to 3" column, and the 8th bit buffered to the reset on the "1 column". This would be in addition to the gates for the "Set" conditions (OR Gates) on the bottom 3 bits.

    If the display part is not completed, I'd suggest a microcontroller for a single chip solution.
     
    Last edited: Feb 27, 2009
  5. beenthere

    Retired Moderator

    Apr 20, 2004
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    You could also use a counter. You would need to decode the output to get the LED's to follow the table.
     
  6. SawabyPlus

    Member

    Feb 27, 2009
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    do u want to serially input the binary format?
    if so, then yes, u will need a 4-bit serial-in parallel-out shift register. u should use a DIP for data input and a PB to provide a shift signal, or more specifically an edge, to trigger the register.
    the outputs LED1-2 should then be implemented by combinational logic using the outputs of the shift register as input.
    what's the nature of that display? is it 7-segment?
     
  7. Digital Design

    Thread Starter New Member

    Feb 22, 2009
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    Hi,

    Thank you so much for your response. Thats what I required to do.

    as for my project, I need to input the 4 binary bits (1010 to 0000) - decreasing order
    the input can decrease by one or by two depending on user input. How can I implement that?

    Thank you.
     
  8. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    An 8 position DIP switch and a load button?

    Or do you need to load high nybble/low nybble with a single 4 position DIP switch + "Load" button, using the LEDs as feedback for which nybble is next?

    I have seen a schematic for manually controlling a 14 pin LCD display using the high 4/low 4 with a DIP Switch and a "load" button, is this similar to your project?

    ETA: Re-Read your last post. Are you looking for an up/down counter that will increment/decrement by either one or two depending on switch positions?
     
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