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Thread: GP2D12 IR sensor..

  1. Question GP2D12 IR sensor..

    hi!
    I and my groupmates are making a Biped Robot.We're using GP2D12 IR sensor to detect the obstacle around the robot.We tried first to test the IR sensor alone to know its accuracy by putting a block/obstacle at a fixed distance but the output is inconsistent.why is that so?Is there any way to have consistent values?

    Hope you can help us.Thank you!

  2. #2
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    Re: GP2D12 IR sensor..

    Define inconsistent. The output is always gonna change a small amount (plus or minus 10% wouldn't surprise me for a $15 sensor) - no measurement device is perfect.

    One thing to be sure of is that you have good capacitance near the sensor. They have a fairly large current draw every time they fire the LED, which is about 30Hz, I find that a 10uF cap right near the sensor works pretty good, but I've also gotten away with one 10uF cap between several GP2D12s, each 12" of wire away from the capacitor.

    -Fergs

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    Re: GP2D12 IR sensor..

    Yeah Inxfergy is absolutely right. If they are way off then check your power supply. Put it on a scope if you can.
    "If A is a success in life, then A equals x plus y plus z. Work is x; y is play; and z is keeping your mouth shut."
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  4. Re: GP2D12 IR sensor..

    These are the sample values that we obtained from our testing.We test our 3 sensors (IR1,IR2,IR3 respectively)-having same distances and position,from a single block.We also vary the distance of the block from IR as we go on with our test.As we move the block the output values also increased to thousands etc..having the same distances and position of the sensors,IR1,IR2,and IR3 supposedly have the same values but why they came up to these values?what are we going to do to obtain the accurate readings especially when it will be attached to the walking biped robot?

    IR_value = 126, 9, 37
    IR_value = 35, 277, 36
    IR_value = 8, 8, 1384
    IR_value = 8, 8, 231
    IR_value = 8, 8, 24
    IR_value = 1384, 1384, 36
    IR_value = 14, 8, 99
    IR_value = 33, 0, 36
    IR_value = 198, 69, 37
    IR_value = 35, 77, 346
    IR_value = 1384, 154, 154
    IR_value = 138, 77, 63
    IR_value = 30, 63, 44
    IR_value = 231, 69, 277
    IR_value = 14, 8, 231
    IR_value = 10, 8, 8
    IR_value = 9, 9, 8
    IR_value = 10, 9, 8
    IR_value = 9, 9, 8
    IR_value = 10, 9, 8
    IR_value = 9, 9, 8
    IR_value = 10, 9, 8
    IR_value = 10, 9, 8
    IR_value = 10, 9, 8
    IR_value = 10, 9, 8
    IR_value = 10, 9, 8
    IR_value = 10, 9, 8

    Thank You very much.

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    Re: GP2D12 IR sensor..

    What are these values? Raw 12-bit ADC? Some converted number - is your conversion function correct?

    -Fergs

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    Re: GP2D12 IR sensor..

    Also how are your sensors mounted? Are they right next to each other? If so, they might be intefering with each other. Try moving them apart by about 3-4 inches, and turning them upright so that are like this:



    If they are turned 90 degrees to their side, they are more likely to interfere with one another (because of how the optics work).

    -Fergs

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    Re: GP2D12 IR sensor..

    How about posting some code? A picture of the bot so that we may see the orientation of the sensors? Better code output?

    Give us -Brick at xx distance / IR =xx

    A little more info will sure go along way to solving your problem.

    BIGBUG
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    YES! Robotics can still be fun!

  8. Re: GP2D12 IR sensor..

    we haven't yet mounted the IRs to the robot when we tested them.so maybe the inconsistencies of the values we gathered was really due to the orientation of the IRs we had.we put them in horizontal manner and somewhat close to each other.the values we had were in centimeters,adc8bit.

    we'll try to experiment again with the IRs and we'll be mounting it already to the robot.Hope we'll get the desired values.

    thank you..

  9. #9

    Re: GP2D12 IR sensor..

    Another curious method I'd heard of, for reducing noise in the Sharps, is by grounding the case. I remember reading that the plastic is conductive, and having a good mount to a metal ground will help. THere is also a good informational analysis of the Sharps at gorobotics.net, but DNS does not appear to be resolving it at the moment.

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    Re: GP2D12 IR sensor..

    I Void Warranties´┐Ż

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