Infra-red Sensor (IR)

What is infra-red (IR)? Infra-red is an electromagnetic wave who wavelength is between 0.75 microns to 1000 microns (1 micron = 1µm). Since infra-red is out of visible light range, we can’t really see IR with naked eye. However, there is a method to “see” IR which will be shown later on. Some of the infra-red applications includes night vision, hyperspectral imaging, and communications. We also use IR daily in our TV remote or any device remote.

IR range in electromagnetic spectrum

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Ultrasonic Sensor HC-SR04

Ultrasonic sensor is a sensor that works on principle similar to radar or sonar. It generates high frequency sound and calculate the time interval between the sending of signal and the receiving of echo. Therefore, ultrasonic sensor can be used to measure distance. HC-SR04 ultrasonic sensor consists of a transmitter, a receiver and a control module.

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