Transmit/Receive

Discussion in 'The Projects Forum' started by picit, Nov 22, 2008.

  1. picit

    Thread Starter New Member

    Dec 14, 2007
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    0
    I need help building a cicuit. I want to place 3 IR sensors at various distances, up to 300 yds away from a control box that will record time and date of a trigger from any of the 3 sensors. I already have control box and 1 sensor ( hardwired ) working. Now i want to use 3 ( remote ) and 1 control box and distinguish which sensor triggered. I was thinking small fm transmitter with 1,2 or3 pulses to determine wich sensor and fm receiver at control box. Does this sound doable (is doable a word?) or is there an easier way?

    The control box is a basic stamp with real time clock if thats any help.

    Thanks
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
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    Do you need any data sent, or just an event trigger? (Doable works fine.)
     
  3. picit

    Thread Starter New Member

    Dec 14, 2007
    7
    0
    Just a trigger, but control box must know which sensor.
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    I would use three transmitters on the same frequency, but with a different tone from each sensor modulating the carrier. Use a set of filters at the receive end to determine the sensor.

    Here is a link to a transmitter - http://www.uoguelph.ca/~antoon/circ/fmt1.htm. Substitute an oscillator for the microphone. Be aware that transmitting on an assigned station frequency will attract expensive attention.
     
  5. picit

    Thread Starter New Member

    Dec 14, 2007
    7
    0
    Thanks for quick replies Beenthere.
     
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