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INDEX |
MY EXPERIENCE IN AUTONOMOUS ROBOTICS | |
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Temperature
Sensor-LM35 Light Sensors-LDR LDR continued Photo Diode Photo Transistor TSOP1738 Distance Measurement Color Sensing Angle Measurement Sensor Links
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DISTANCE MEASUREMENTS For a small distance measurement we can use a photo diode or photo transistor, but only distance up to 5-7cm. You just connect the output to ADC or any comparator to measurement. Suppose if we use one LM324 for distance measurement, you can measure 1cm ,2cm,3cm,4cm. You just connect a 330 ohm in series with IR LED. At the other end use a photo diode in reverse region. If you want a good distance then you
should use 38Khz modulated IR with TSOP1738
detector. Use IC555 to generate 38Khz square wave. Better
tutorials available in roboticsindia, see
Suppose if you want to measure distance
from a fixed point. This is done by varying the
frequency. When S1=1 then Raeq=R1//Ra1=
R1Ra1/(Ra1+R1). So this will produce a different
frequency some between 36 to 40Khz. When S2=1 Raeq=R1//Ra2. And
when S1=S2=1 then Raeq=R1//Ra1//Ra2. By varying S1,S2 you can
measure the distance from it. But this mostly require the need of
some
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