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74hc595 help shift register

  1. Mar 13, 2014 #1
    I have a 13x16 led screen I'm making(leds are put together), but now I'm trying to set up 4x 74hc595's. I've looked online and lots of the site seam similar but don't work and I do not know/understand how I can get my arduino to send (for example have the shift registers do "1010101010101010").
  2. jcsd
  3. Mar 14, 2014 #2


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    Gold Member

    here is a site

    But I don't understand the capacitor on the latch pin. In the text they say 0.1uF. If you use 1uF you will need to have a very long latch pulse. You shouldn't need a capacitor at all on the latch pin, but you need a capacitor (0.1uF ceramic) across the power pins.

    Set the data (pin 14) to a value.
    pulse the shift clock high then low (pin 11)
    do that 8 times, each time with a different data value.
    Then pulse the latch clock high then low (pin 12). That will transfer the data to the output.

    Make sure you have correct power, ground, have clear (pin 10) high and output enable (pin 13) low.
  4. Mar 14, 2014 #3
    That's what I originally used but I never worked right... I have. Currently 4 connected together like how it shows on there with an led only on the first of each. I set my arduino so it sets them all to high but leds didn't turn on
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