Quick question about shift registers

Discussion in 'General Electronics Chat' started by jaygatsby, Dec 29, 2011.

  1. jaygatsby

    Thread Starter New Member

    Nov 23, 2011
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    I want to use three 8 bit shift registers to enter / latch 24 bits. I see several 8 bit shift registers on Jameco. Is it normal to 'chain' shift registers together, 3 in my case, to obtain a desired bit width? Or is that not how they work?

    Thank you
     
  2. crutschow

    Expert

    Mar 14, 2008
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    Yes, you can "chain" them to give as many bits as you need.
     
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  3. SgtWookie

    Expert

    Jul 17, 2007
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  4. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    If you are tying them together for an LED matrix, take a look at the Maxim line, they are I2C controlled, and are programmable current sinks for dimming and other features LED billboards use. MAX6956.

    I was sent some samples and am extremely impressed, especially since they can be another 28 I/O ports instead of constant current sinks for LED driving, or a mix and match of both I/O and LED current sinks.
     
  5. jaygatsby

    Thread Starter New Member

    Nov 23, 2011
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    What I intend to do is have a keypad connected to the shift registers. The registers Sgt gave look like they will work well. I'll use the keypad connected to the chip serial inputs (i'm using 3 chips), and the outputs will go to counters... when the user presses enter on the keypad the jam inputs of the counters will read from the output of the shift registers.
     
  6. SgtWookie

    Expert

    Jul 17, 2007
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    You might find it interesting that you only need one pin to shift out data into the registers, and latch it into the outputs. :eek: ;)

    Have a look at this page on Roman Black's site:
    http://www.romanblack.com/shift1.htm
     
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