How to make Ultrasonic Range Finder using HC-SR04

In this post, we will be discussing about making a Ultrasonic Range Finder by using HC-SR04 sensor very easily at home. 

You can use any beginner kit of Arduino to make it, as the parts required are easily available with it.

Things required-

• Arduino Uno R3

• Breadboard

• Jumper Wires

• HC-SR04 sensor

• Buzzer

• LED

• Resistor 220ohm

Procedure-

• The HC-SR04 Ultrasonic Module has 4 pins, Ground, VCC, Trig and Echo.

• The Ground and the VCC pins of the module needs to be connected to the Ground and the 5 volts pins on the Arduino Board respectively and the trig and echo pins to any Digital I/O pin on the Arduino Board.

• The HC-SR04 sensor attach to the Breadboard

• The Sensor VCC connect to the Arduino Board +5V

• The Sensor GND connect to the Arduino Board GND The Sensor Trig connect to the Arduino Board Digital I/O 9

• The Sensor Echo connect to the Arduino Board Digital I/O 10 Buzzer and LED The Buzzer attach to the Breadboard

• The Buzzer long leg (+) connect to the Arduino Board Digital 11 The Buzzer short leg (-) connect to the Arduino Board GND

• The LED attach to the Breadboard The Resistor connect to the LED long leg (+)

• The Resistor other leg (from LED's long leg) connect to the Arduino Board Digital 13

• The LED short leg (-) connect to the Arduino Board GND

Source Code:

// defines pins numbers

const int trigPin = 9;

const int echoPin = 10;

const int buzzer = 11;

const int ledPin = 13;

// defines variables

long duration;

int distance;

int safetyDistance;

void setup() {

pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output

pinMode(echoPin, INPUT); // Sets the echoPin as an Input

pinMode(buzzer, OUTPUT);

pinMode(ledPin, OUTPUT);

Serial.begin(9600); // Starts the serial communication

}

void loop() {

// Clears the trigPin

digitalWrite(trigPin, LOW);

delayMicroseconds(2);

// Sets the trigPin on HIGH state for 10 micro seconds

digitalWrite(trigPin, HIGH);

delayMicroseconds(10);

digitalWrite(trigPin, LOW);

// Reads the echoPin, returns the sound wave travel time in microseconds

duration = pulseIn(echoPin, HIGH);

// Calculating the distance

distance= duration*0.034/2;

safetyDistance = distance;

if (safetyDistance <= 5){

  digitalWrite(buzzer, HIGH);

  digitalWrite(ledPin, HIGH);

}

else{

  digitalWrite(buzzer, LOW);

  digitalWrite(ledPin, LOW);

}

// Prints the distance on the Serial Monitor

Serial.print("Distance: ");

Serial.println(distance);

}