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making ir beacon — Parallax Forums

making ir beacon

patrick van der Tolpatrick van der Tol Posts: 9
edited 2012-07-02 10:41 in Accessories
Hello,

im new in electronics and i want to build an ir beacon for my boe-bot. How do i make an ir beacon? i have read the instruction in my boe bot manual about ir.
i dont understand how i can build an ir transmitter so the boe bot can travel to it. can it be done with an pic 555? is there some circuit diagram?

Please help me out

Thanks for the help!

Best regards
Patrick

Comments

  • Cats92Cats92 Posts: 149
    edited 2012-07-02 08:20
    Hello,

    i made something like that 2 years before , but wit a Propeller chip ( there a good exemples of IR detection in the Propeller tutorials and Propeller exchange objects : OBEX)

    You have to put the IR detector at the bottom of a small black box ( i used a LEGO brick ) and cut a small slit in the cover of the box to make the detection directional.
    It is easy to find strong ir emitting LEDs in electronic stores .

    Instead of an IR beacon you may try a polarised light detection
    Using a beacon made with a lamp and a piece off polarizing film ((a LED lamp is better it gets less hot).
    For detection on the bot : 2 light detectors behind 2 pieces of polarizing film turned at right angles (horizontal and vertical). So you get 2 detection values H and V : and if the beacon emits horizontal polarized light the H/V becomes maxi when the detector faces the beacon.
    Using this you may have 2 diff
  • kwinnkwinn Posts: 8,697
    edited 2012-07-02 10:02
    You can use a 555 timer chip for driving an IR beacon at a fixed frequency. Download the 555 data sheet and look at the "astable operation" circuit.
  • ercoerco Posts: 20,256
    edited 2012-07-02 10:41
    Makin' bacon or beacon? :)

    You'll need a 556 or better to generate a trackable 38 khz IR signal. The signal must be modulated (pulsed) in order for the IR detector to pick it up. Scribbler beacon info at http://www.botmag.com/articles/scribbler.shtml You can simply set different pulsing frequencies for multiple beacons in order to discriminate between them. See http://forums.parallax.com/showthread.php?130927-Low-Tech-IR-Remote

    A Scribbler has "set and forget" motor drivers, but BoeBot does not. For a BoeBot, you may need to add a Servopal to reduce processor overhead in order to track to the beacon signal.
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