Arduino: Building exciting LED based projects and espionage devices

IR sensors

We have learned the basics of IR communication and IR LEDs, so now we will move on to making our own IR sensor.

There are various types of IR sensors, depending upon the application. Proximity sensors, obstruction sensors, and contrast sensors (used in line follower robot) are a few examples which use IR sensors.

Working mechanism

An IR sensor consists of an IR LED (which works as a transmitter) and a photodiode (which works as a receiver) pair. The IR LED emits IR radiation, which, on receiving at the photodiode dictates the output of the sensor.

There are different types of use cases for an IR sensor. For example, if we held an IR LED directly in front of the photodiode, such that almost all the radiation reaches the photodiode, this ...