IR sensor schematic

Discussion in 'The Projects Forum' started by chimera, Oct 31, 2010.

  1. chimera

    Thread Starter Member

    Oct 21, 2010
    I have been meaning to design a robot which basically avoids obstacles. So I decided to make a IR sensor and brightness sensor. Attached is a written step by step process of designing a IR sensor that would be remain turned on when no obstacle is in front and will turn off when an obstacle is detected. The blue LED is a general purpose Led to visually show how the circuit performs.

    I have covered the IR led and the IR phototransistor with heat shrink tubing to make it less susceptible to ambient light.

    This procedure will come in hand if someone else also decided to make one.

    Please comment
    • 1.jpg
      File size:
      140.3 KB
    • 2.jpg
      File size:
      135.3 KB
    • IRSENSOR.pdf
      File size:
      180.4 KB
    Last edited: Oct 31, 2010
  2. bertus


    Apr 5, 2008

    I do not see the attachment.
    Did you forget it?

  3. chimera

    Thread Starter Member

    Oct 21, 2010
    it should be attached now
    Last edited: Oct 31, 2010
  4. jpanhalt


    Jan 18, 2008
    When, not if, you get into microcontrollers, you can do error correction a different way. Here is an old link to noise correction using the 12F/12C series PIC.

    Scroll to the 12C508 project. There are also useful links therein to the Dallas group.

    I have been using that method in a device for several years. It works indoors, outside, bright sunlight, overcast, etc.

  5. chimera

    Thread Starter Member

    Oct 21, 2010
    i was thinking about it..and have been reading up on the subject. So far, I think the Arduino Uno seems like a good start off point.. I think i should start a new thread for this topic
  6. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    That is a great link!

    I usually add something similar to the whisker/contact sensors in addition to IR and/or sonar, sometimes things appear out of nowhere (kid's hands, cats, paws, etc), and miss the IR sensors. Other things that are too small to catch, such as thin chair legs when off axis/in a turn will be caught by the whiskers and stop it before it gets scratched.

    Remember to add a reverse direction option, obstacle avoidance robots have a tendency of getting stuck somewhere that they need to back up.

    Lastly, a beeper or "SOS" LED to go off when the program is out of solutions for whatever spot it got into. This helps you to program better and learn what is going on.

    For starting out, it doesn't matter if you use an Arduino or Picaxe, the languages are a bit different, but the concept is the same.

    To keep costs down, you'll eventually start using just the AVR (Arduino) or PIC (PicAxe, Basic Stamp) IC and a programmer, doing the program design and compiling on a PC. This changes the cost of a robot control from $30-$50 down to under $10 each, after the one time cost of the programmer.