Published May 10, 2021 © CC BY

Distance measurement using HCSR04

DIY distance measuring device using HCSR04 ultrasonic sensor.

BeginnerFull instructions provided292

Things used in this project

Hardware components

Arduino Nano R3

Ultrasonic Sensor - HC-SR04 (Generic)

Jumper wires (generic)

Software apps and online services

Arduino IDE

Story

DIY distance measuring device using HCSR04 ultrasonic sensor.

HowUltrasonicSensorworks-

Ultrasonic sensors work by sending out a sound wave at a frequency above the range of human hearing. The transducer of the sensor acts as a microphone to receive and send the ultrasonic sound. Our ultrasonic sensors, like many others, use a single transducer to send a pulse and to receive the echo. The sensor determines the distance to a target by measuring time lapses between the sending and receiving of the ultrasonic pulse.

The working principle of this module is simple. It sends an ultrasonic pulse out at 40kHz which travels through the air and if there is an obstacle or object, it will bounce back to the sensor. By calculating the travel time and the speed of sound, the distance can be calculated.

Ultrasonic sensors are a great solution for the detection of clear objects. For liquid level measurement, applications that use infrared sensors, for instance, struggle with this particular use case because of target translucence.

For presence detection, ultrasonic sensors detect objects regardless of the color, surface, or material (unless the material is very soft like wool, as it would absorb sound.)

To detect transparent and other items where optical technologies may fail, ultrasonic sensors are a reliable choice.

Ultrasonic sensor working principle

Code

Distance Measurement using HCSR04

#define trigPin 10
#define echoPin 11

void setup() 
{
  Serial.begin (9600);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
}

void loop() 
{
  long duration, distance;
  digitalWrite(trigPin, LOW);        
  delayMicroseconds(2);              
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);           
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  distance = (duration/2) / 29.1;
  if (distance >= 200 || distance <= 0)
  {
    Serial.println("Out of range");
  }
  else 
  {
    Serial.print(distance);
    Serial.println(" cm");
  }
  delay(500);
}

Credits

manodeep

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Distance measurement using HCSR04

Things used in this project

Hardware components

Software apps and online services

Story

Schematics