Working Principle of IR Sensor
*Sensor keeps transmitting infrared light and when an object comes near, it is detected by the sensor by monitoring the reflected light from the object.
*IR light is not visible to naked eye.
*IR light transmitted by IR LEDs is detected by Photodiode.
*Photodiode generates the voltage depending on the intensity of light.
*When there is NO OBJECT or DARK OBJECT present, then transmitted IR will not reflect back to RX(photodiode) and Vout(output) will be LOW.
*When LIGHT COLOR OBJECT is present, then transmitted IR will reflect back to RX (photodiode) and Vout(output) will be HIGH.