LED signs could soon hide secret messages

Discussion in 'privacy technology' started by mood, Aug 29, 2018.

  1. mood

    mood Updates Team

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    LED signs could soon hide secret messages
    August 29, 2018
    https://www.engadget.com/2018/08/29/led-signs-could-soon-hide-secret-messages/
     
  2. mirimir

    mirimir Registered Member

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    Wow. Very cool. One could also embed messages in third-party video :)
     
  3. caspian

    caspian Registered Member

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    And some music so we could dance a little jig! *puppy*
     
  4. brians08

    brians08 Registered Member

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    LED data is true line of sight. You have to know where it is and then be in the light beam to pick up anything.
    The article says a single LED is only good a few inches but that makes no sense. Your flat screen remote uses a single LED and that works at 20' or more.
    Imagine a big animated sign with thousands of LED pixels. Take one LED and replace it with a wavelength slightly off from the rest and modulate the light pulses with data. Use a bandpass filter on the receiver to increase the SNR.
     
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