Arduino with Infrared Sensor
A rduino UNO is a microcontroller board- it is the brain of any electronics project. IR sensor, on the other hand, is an infrared rays transmitter and receiver. In the following project, we will learn the working principle of IR sensor followed by its application as a discriminator between black and white surfaces and as an obstacle detector with Arduino UNO.
IR Sensor
FC-51 IR Sensor emits and detected infrared radiations. IR radiations are part of the electromagnetic spectrum, with wavelength higher than that of visible light, and are generally invisible to the human eye.
The IR sensor consists of:
- IR Emitter LED: Emits infrared light
- IR Receiver: A photodiode with resistance depending on the amount of IR light falling on it
- Distance Adjuster: Changes detection distance
- Vcc Pin: Provides 3–5 V input voltage
- Gnd Pin: Ground input
- Out Pin: Transmits output signal from the sensor to Arduino
- Obstacle LED: Turns on when light falls on IR Receiver
- Power LED: Turns on when the sensor is connected to a voltage source
Working of IR Sensor:
As per the property of light — light falling on a smooth shiny surface bounces off in a particular direction i.e. reflection — the ray send by IR Transmitter gets reflected from a surface and falls on IR Reciever. Subsequently, the receiver’s resistance drops, and a LOW/0 signal is sent by the OUT pin to the microcontroller.
Similarly, when the light sent isn’t reflected either because there is no surface ahead or the surface ahead absorbs light, the resistance of the receiver rises and a HIGH/1 signal is sent by OUT pin to the microcontroller.