Working of the Ultrasonic Sensor

The Ultrasonic Sensor works on the principle of reflection, let us see how

• The sensor is used to emit waves known as ultrasound with a frequency of 40 KHz.
• The transmitted wave moves in a straight line path and gets obstructed by an object if present.
• After being obstructed, the wave reflects and is detected by the sensor. The time of transmission and reflection of the wave is noticed and the distance of the object is calculated using the speed-time formula.

Given Below is the Ultrasonic Sensor

Principle: If you carefully look at the diagram above, you will see that there is a transmitter. This component is responsible for emitting waves of an appropriate frequency that can travel far i.e. it should be able to transmit the ultrasound. Once the ultrasound waves are emitted, they continue a straight line path until they find an object. As shown in the figure, when the ultrasound waves are blocked by any object, the waves reflect. The receiver is present to receive the incoming waves after reflection. Once the reflected wave is received, we note the time taken by the waves to detect the object and predict the distance using this formula.

s= 2d/t

where s is the speed of the wave,

d is the distance traveled until reaching the object,

and t is the total time taken

Note that the factor ‘2’ appears because the time noted is for the period when the wave strikes the object and then comes back.

Sensors are widely used for detecting devices by approximating their distance from the source. One such example of a sensor is the HC-SR04 ultrasonic sensor which uses the SONAR technique for the sensing purpose. The main feature of this sensor is to mimic the nature of bats and therefore predict the distance of objects without actually establishing contact with the device.

In this article, we will study how to design this ultrasonic sensor using the Arduino board and programming software. We will study the specifications needed for this sensor, and the methods and circuit diagrams used for designing this sensor. In addition to this, we will see the Arduino code written on IDE that will result in a sensor.