Digital IR sensor

Discussion in 'The Projects Forum' started by varunme, Jan 2, 2012.

  1. varunme

    Thread Starter Member

    Sep 29, 2011
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    Anybody has a schematic for digital IR sensor (not analogue) ?
     
  2. DickCappels

    Moderator

    Aug 21, 2008
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    Not sure what you mean by "digital" and "IR" since the terms can be fitted to a wide variety of things. An IR sensor probably starts out analog since all of the detectors I have been able to think of are analog in nature. The question after that is how you turn that analog information into digital and how you want the digital information encoded or displayed.

    You could simple connect a photocell or solar cell to a digital voltmeter and set the voltmeter of the current scale -expect something in the range of up to microamps to several milliamps for solar cells an area of about that of a U.S. quarter, depending upon the fabrication method and the output of the IR light source.

    You can see the response of a typical solar cell at this URL:
    http://www.kellerstudio.de/repairfaq/sam/sipdresp.gif

    The web page upon which it is found may also be helpful:
    http://www.kellerstudio.de/repairfaq/sam/laserioi.htm
     
  3. varunme

    Thread Starter Member

    Sep 29, 2011
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    can we make digital output from the sensor (1 and 0) than just analogue voltages by using opamp or something ?
    because i want to just turn on a port off a port using the sensor , just as using a push button
     
    Last edited: Jan 5, 2012
  4. MrChips

    Moderator

    Oct 2, 2009
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    All digital signals are analog.
     
  5. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    IR Receivers have a decoder built in, so they output pulses corresponding to the IR signal.

    I'd strongly recommend against turning something on or off based on the leading edge of any IR signal that the detector gives on the output.

    TV remotes send many pulses for different channels and functions, which would cause your circuit to turn on and off very quickly.

    In addition, requiring a certain sequence of IR pulses, say VOL+ then 5 then 4 on a TV keypad to turn the power off would eliminate unintended power state changes from any remote. Using a single character leaves a lot of options for accidental triggering.

    Something like a large logic circuit with flip flops, or a microcontroller running behind the IR Receiver to put out a logic high after the correct sequence is received.
     
  6. DickCappels

    Moderator

    Aug 21, 2008
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    varunme likes this.
  7. varunme

    Thread Starter Member

    Sep 29, 2011
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    I got a fluctuation in the LED , but, its only 4.5V when IR is on, and when off, its 5V
    how can we convert to digital ?
     
    Last edited: Jan 17, 2012
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