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I need help in IR for AVR

Discussion in 'AVR' started by beginer electroner, Oct 3, 2007.

  1. beginer electroner

    beginer electroner New Member

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    Hi
    I am working on a project to send a signal when aomeone cross the door...
    I used an IR led as transmitter (the transmitter circuit contain 555 IC )
    and in the receiver part I used a receiver transistor and LM324
    put I couldn't switch the microcontroller, i mean i didn't have any signal in the output.......
    could any one help me giving me a working IR circuit.....

    thank you all
     
  2. HarveyH42

    HarveyH42 Banned

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    A schematic would probably get more responses...

    My very first origional AVR project, was an IR proximity detector. It's only good for about 2 feet, but didn't overdrive the IR LED or put pauses in the 38 kHz. I used a IR reciever module, fairly common 3 lead device used with many remote control electronics (TV, Stereo, VCR...). Anyway, mine was reflective, couple feet wasn't bad. I got the hardware side off Nigel's PIC tutorials. The software is easy, the module is normally HIGH, but drops low when it detects the carrier (38kHz), but it's not really picky about the frequency. My biggest problem was getting the Tiny13 to generate the 38kHz signal.

    Anyway, I posted lots of questions in this forum while building it, been about a year ago, don't remember the title. Will search later.
     
  3. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    Why did you struggle?, it's dead simple - just set an I/O high, wait half a wavelength and make it low again, wait half a wavelength, make it high again - repeat as long as required. Gives accuracy to within one instruction cycle, and an accurate number of exact cycles transmitted.
     

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