An infrared sensor emits electromagnetic radiation (which is invisible to the human eye) and also detects electromagnetic radiation, so as to sense objects around it. Every object emits thermal radiation. This radiation can be detected by the Infrared (IR) sensor. The IR sensor can detect the thermal radiation emitted by objects.

We have the Active Infrared sensor and the Passive Infrared (PIR) sensor. The active infrared sensor has a transmitter and a receiver. The transmitter sends infrared radiation which hits an object and is reflected back to the receiver of the sensor. The PIR sensor only has a receiver. It detects infrared radiation emitted by objects around it. Hence it is mostly used for motion detection.  

In this project, we interfaced the IR sensor with the Arduino Uno board and we also connected an LED to it. When the IR sensor discerns any thermal radiation, the LED turns ON, indicating the presence of an object within that environment 

Circuit Description:

The IR sensor has 3 pins; Vcc, GND, and OUTPUT. The Vcc is connected to the 5V pin on the Arduino, the OUTPUT pin to Pin 2 on the Arduino and the GND pin to the GND pin on the Arduino. An LED was also connected to pin 13 of the Arduino and GND of the IR sensor.

Areas of Application:

This can be applied in the following areas;

  1.  Room lighting: The IR sensor can be used for an automatic lighting system.
  2. Security Alarm systems: The IR sensor is interfaced with a buzzer which triggers an alarm when a signal is sent to it by the sensor.
  3. Remote control: The IR sensor(receiver) is interfaced with Television sets, DVD players, and other devices that can be controlled using a remote(transmitter).


Arduino Code

#Embedded systems