Connecting IR sensor to motherboard digital I/O

Discussion in 'The Projects Forum' started by leonard.s, Feb 13, 2011.

  1. leonard.s

    Thread Starter New Member

    Feb 13, 2011
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    Hi,

    I am a newbie to electronics circuity and would like to seek the forum's opinion.

    In my current project, we're required to connect existing 8 IR receivers to 8 digital I/O pins on a motherboard. The motherboard I/O pins can be set as input pins, with 0V and 5V as the digital logic signal.

    The existing IR receivers are Pepperl Fuchs LA31. The motherboard is Advantech AIMB N270

    What is the proper way to connect the IR sensor receivers to the digital I/O pins? My initial queries are (sorry, they're very newbie questions):
    1) The datasheet for the IR receiver says operating voltage of 12V ... 24V DC. Is this the signal output voltage?
    2) Will connecting the IR sensor receiver signal output to the motherboard digital I/O pin cause the motherboard to fry?
    3) Do I need to have a power regulator or step down to convert 12V to 5V?
    4) Is there any power regulator that can take in 8 12V inputs and convert it to 8 5V outputs? Those that I know are only 1 input and 1 output (like LM7805), and therefore would require to have 8 of those
     
  2. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    http://labjack.com/

    General purpose PCs aren't really set up as controllers, you need a "glue circuit" to convert signal to serial (RS-232 or USB).
     
  3. leonard.s

    Thread Starter New Member

    Feb 13, 2011
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    Hi thatoneguy,

    Thanks for the reply.

    In this case, the motherboard already have a digital I/O pins (It has 16 pins which can be set as input or as output pins). Is it necessary to convert the signal to serial, since from the OS I am able to read the I/O pins directly?
     
  4. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    No, if it has I/O ports, you can poll them continually with software, unless they offer interrupts.

    The board you linked is a general purpose x86 board, which may have I/O built in. The important part is the OS. You'll need to consult the OS documentation to access the ports.

    Depending on what you'd like to achieve, a PIC with USB support, or as a standalone with an LCD display may do what you'd like. Adding an SD card would allow logging ability with much less power than an x86 motherboard.
     
  5. leonard.s

    Thread Starter New Member

    Feb 13, 2011
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    Hi thatoneguy,

    From the OS / software point of view, I am able to read from the input pins (when connected to 5V signals).

    What I am afraid is in connecting the IR sensor receiver signals directly into the I/O pins. The datasheet of the IR sensor receiver doesn't specifically say the voltage of the signal. I am afraid that it may fry the motherboard. For this kind of cases, do I need to have power regulator so that the input signal is regulated to 5V? Do I need to have analog-digital-converter?
     
  6. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    You will need an ADC unless you get an IR Receiver with digital output.

    Sharp IR Rangefinders offer both digital and analog interfaces available at slightly different price points.
     
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