Long Range IR: How to build?

Discussion in 'The Projects Forum' started by jrengrsil, Feb 12, 2009.

  1. jrengrsil

    Thread Starter New Member

    Feb 12, 2009
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    I need references/schematics on long-range infrared transmitter and receiver

    Im building a bot that supposed to find and approach a stationary beacon up to at least 5 meters away, (the minimum required is 5 meters, exceeding that is fine)I have decided to use IR for the beacon since sound based and RF based proved difficult due to certain traits that would prove a hindrance to the positional tracking

    The bot also has a an IR collision sensors like the ones shown here http://www.e-gizmo.com/KIT/Collision.HTM
    so I have to make sure that the beacon's signal does not interfere with the obstacle detector

    Thanks.
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
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    Make sure the modulation on the beacon is at at different and non-harmonic frequency.
     
  3. kubz

    New Member

    Apr 4, 2009
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    Hello,

    I'm also building a IR beacon for bot navigation. I have built a simple transmitter with a 555 timer (modulation) and receiver with a phototransistor and an quad op-amplifier... last week.

    The test shows very short range, even when the op-amplifiers make the signal 1000x stronger. The width of a desk is max... I can add more info...

    Do you have any better results you could share?
     
  4. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    I would make a parabolic reflector, and have the IR receiver placed at the focal point of the parabola. Aluminum foil isn't ideal, but it is inexpensive and would work reasonably well.

    Nutating (moving the parabola from side to side) should give you variations in the strength of the received signal; then you can "zero in" on the strongest direction.
     
  5. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    Does the beacon transmit a 360 deg. pattern, or does it rotate? Can bot's antenna rotate, till it receives a hit, then oscillates as Sgt. suggests?
     
  6. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    Might review post by electrazy , similar problem.
     
  7. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    I've seen "Beacon Finders" created as a ring of 8 IR Transistors mounted around the periphery of a circle, every 45 degrees. Microcontroller reads/decodes input from all 8, and moves towards the strongest source. Make sure the modulation frequency and pattern is a good deal different than the obstacle detection IR.
     
  8. hgmjr

    Moderator

    Jan 28, 2005
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