Time measurement between two signals using microcontroller

Discussion in 'General Electronics Chat' started by indiansiva555@gmail.com, Jan 26, 2012.

  1. indiansiva555@gmail.com

    Thread Starter New Member

    Jul 24, 2011
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    Please help....
    How to measure time between two signals using microcontroller. Here I am using a laser pulse. The time is to be measured between transmitted laser signal and its reception (after reflection)
     
  2. crutschow

    Expert

    Mar 14, 2008
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    That is not a trivial measurement due to the short time of flight. It requires a high speed comparator and digital counter. Read this for more info.
     
  3. indiansiva555@gmail.com

    Thread Starter New Member

    Jul 24, 2011
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    Thank you Senior.
    Your link provided me useful information about the working principle of laser range finders. But I am unaware of the comparators to be used and I am a beginner. So please help me in choosing the comparator.
     
  4. MrChips

    Moderator

    Oct 2, 2009
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    You cannot do this with a laser unless you are trying to set up a sophisticated physics laboratory experiment.
     
  5. nsaspook

    AAC Fanatic!

    Aug 27, 2009
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    If your pulse time resolution is in the range of 1 ns then a PIC (and a few external parts) with the CTMU module in TDR mode might work.

    http://www.ecnmag.com/Articles/2009/07/Low-Cost,-High-Resolution-Time-Measurement-Application/
     
  6. crutschow

    Expert

    Mar 14, 2008
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    What distance are you trying to measure?
     
  7. indiansiva555@gmail.com

    Thread Starter New Member

    Jul 24, 2011
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    I want this to be installed in my car, so that I would be able measure the distance between my car and the one in the front. I also wan this to work as a proximity to sense a vehicle entering into my lane at a range of 30m. I don't want to make it very accurate. I am doing this to get an idea of such systems as I am a student.
     
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