Ultrasonic sensor with Arduino Nano – How does work Ultrasonic sensor

Ultrasonic sensors are widely used in various applications, from robotics and automation to home security and parking assistance systems. These sensors utilize sound waves to detect the presence and measure the distance of objects. Let's explore how an ultrasonic sensor works, particularly when used with an Arduino Nano board.

Principle of Ultrasonic Sensors Ultrasonic sensors work on the principle of sound wave reflection. They emit high-frequency sound waves, typically in the range of 40 kHz to 400 kHz, which are beyond the human hearing range. When these sound waves encounter an object, they bounce back, and the sensor detects the reflected waves.

The time it takes for the sound wave to travel to the object and back is measured by the sensor. By calculating this time-of-flight (ToF), the sensor can determine the distance to the object using the following formula:

Distance = (Speed of Sound × Time of Flight) / 2

The speed of sound in air is approximately 343 meters per second (m/s) at 20°C.

Components of an Ultrasonic Sensor An ultrasonic sensor typically consists of the following main components:

  1. Transmitter: This is a piezoelectric crystal that converts electrical signals into high-frequency sound waves.
  2. Receiver: Another piezoelectric crystal that converts the reflected sound waves back into electrical signals.
  3. Control Circuit: This circuit controls the timing and synchronization of the sound wave transmission and reception.

Using an Ultrasonic Sensor with Arduino Nano To use an ultrasonic sensor with an Arduino Nano, you need to connect the sensor's pins to the appropriate Arduino pins. Typically, an ultrasonic sensor has four pins:

  1. VCC: Connect this to the 5V pin on the Arduino Nano.
  2. GND: Connect this to the ground (GND) pin on the Arduino Nano.
  3. Trigger: This pin is used to initiate the sound wave transmission. Connect it to a digital pin on the Arduino Nano.
  4. Echo: This pin outputs a pulse signal that corresponds to the time it takes for the sound wave to travel to the object and back. Connect it to a digital pin on the Arduino Nano.

Here's a basic example of how to use an ultrasonic sensor with an Arduino Nano:

cpp // Define the pins for the ultrasonic sensor const int trigPin = 9; const int echoPin = 10;

void setup() { Serial.begin(9600); // Initialize serial communication pinMode(trigPin, OUTPUT); // Set the trigger pin as an output pinMode(echoPin, INPUT); // Set the echo pin as an input }

void loop() { // Send a 10-microsecond pulse to the trigger pin digitalWrite(trigPin, HIGH); delayMicroseconds(10); digitalWrite(trigPin, LOW);

// Measure the duration of the echo pulse long duration = pulseIn(echoPin, HIGH);

// Calculate the distance in centimeters long distance = (duration / 2) / 29.1;

// Print the distance to the serial monitor Serial.print("Distance: "); Serial.print(distance); Serial.println(" cm");

delay(100); // Wait for 100 milliseconds before the next measurement }

This code sends a 10-microsecond pulse to the trigger pin, which causes the ultrasonic sensor to emit a sound wave. The code then measures the time it takes for the echo pulse to be received on the echo pin, and calculates the distance to the object based on the time-of-flight.

Ultrasonic sensors are versatile and can be used in a wide range of projects, from simple distance measurements to complex robotic applications. By understanding how they work and how to integrate them with an Arduino Nano, you can create innovative and practical IoT projects.

Back to Lisa's Column