Working With HC-SR04 Ultrasonic Sensor

Introduction

 

In my previous article I explained the working with LM35 Temperature to get accurate room temperature value and in this article I'll show you how can we work with HC-SR04 Ultrasonic Sensor to get the accurate distance of the objects and some other functionalities. etc. Ultrasonic Sensor have many uses in Medicine field.

 

Requirements

• Arduino
• Bread Board
• Ultrasonic Sensor (HC-SR04)
• Led
• Jumper Wires 
• Ultrasonic Sensor (HC-SR04)

                

               

                                             Figure 1: HC-SR04 Ultrasonic Sensor 

 

What Ultrasonic Sensors can do? 

• The HC-SR04 Ultrasonic Sensor uses detection of objects
• Measurement of length 
• Thickness, amount and destruction of the objects  etc.

Connection

1. Vcc pin to the 5v
2. Trig pin to digital pin 5
3. Echo pin to digital pin 6
4. Gnd to Gnd  

Program

# define echoPin 5 // Echo Pin
# define trigPin 6 // Trigger Pin
# define LedPin 13 // Led
int maxRange = 300; // Maximum range
int minRange = 0; // Minimum range
long dur, dist; // Duration used to calculate distance
void setup()
{
    Serial.begin(9600);
    pinMode(trigPin, OUTPUT);
    pinMode(echoPin, INPUT);
    pinMode(LedPin, OUTPUT);
}
void loop()
{
    digitalWrite(trigPin, LOW);
    delayMicroseconds(2);
    digitalWrite(trigPin, HIGH);
    delayMicroseconds(10);
    digitalWrite(trigPin, LOW);
    dur = pulseIn(echoPin, HIGH);
    dist = dur / 58.2;
    if (dist >= maxRange || dist <= minRange)
    {
        Serial.println("-1");
        digitalWrite(LedPin, HIGH);
    }
    else
    {
        Serial.println(dist);
        digitalWrite(LedPin, LOW);
    }
    delay(50);
}

Output

 

             

                                                   Figure 2: Output 

 

 Explanation

• #define echoPin, trigpin, ledpin are the variables that takes the values of these pins during compile time.
  
  
• And set the maximum range and minimum range duration to find out the distance of the objects.
  
  
• The Setup() function is used to set the pinMode to the trigpin, echopin and the ledpin.
  
  
• And the  loop() function is used to set our own condition what the Ultrasonic Sensor want to do.
  
  
• dist = dur/58.2; //Calculate the distance (in cm) based on the speed of sound.
  
  
• if (dist >= maxRange || dist <= minRange) and set the condition to the ultrasonic sensor. Based up on this condition when the object is found in the ultrasonic sensor the led is blink otherwise it will be static one.

Conclusion

 

And finally we conclude that with ultrasonic sensor we made the object finder.