LESSON 11 - The Mesurment Distance with Arduino And HC-SR04

In this lesson, I've explained The distance measurment with aduino and HC-SR04 module. I've mesured the distance in centimeter and inch.



Ultrasonic Ranging Module HC - SR04

Product features:

Ultrasonic ranging module HC - SR04 provides 2cm - 400cm non-contact measurement function, the ranging accuracy can reach to 3mm. The modules includes ultrasonic transmitters, receiver and control circuit. The basic principle of work:

(1) Using IO trigger for at least 10us high level signal,

(2) The Module automatically sends eight 40 kHz and detect whether there is a pulse signal back.

(3) IF the signal back, through high level , time of high output IO duration is the time from sending ultrasonic to returning.

Test distance = (high level time×velocity of sound (340M/S) / 2,

Wire connecting direct as following:

• 5V Supply 
• Trigger Pulse Input 
• Echo Pulse Output 
• 0V Ground 

Electric Parameter 

Working Voltage	DC 5 V
Working Current	15mA
Working Frequency	40Hz
Max Range	4m
Min Range	2cm
MeasuringAngle	15 degree
Trigger Input Signal	10uS TTL pulse
Echo Output Signal	Input TTL lever signal and the range in proportion
Dimension	45*20*15mm

Figure 1 - HC-SR04 Module

BUZZER

It is a tiny speaker that produces a "beep" sound proportional to the size of the electronic signal applied to it. There are two types, one with a circuit and one without a circuit. A stronger sound output is obtained from the one with a circuit.

Figure 2 - Buzzer

The Circuit of Measurment Distance 

Firstly, I've connect the LCD display and the i2C module in Figure 3. Then I've set up the circuit in Figure 4.

Figure 3 - The LCD display and I2C Module

Figure 4 - The circuit of distance mesurement

ARDUINO UNO Program

#include <LiquidCrystal_I2C.h>

#include <Wire.h>

const int trig = 2, echo = 3, buzzer=6; 

float zaman,cm,inc ;

 // LCD ekan Tanımlanıyor (The initialization LCD Display)

LiquidCrystal_I2C lcd(0x27,2,1,0,4,5,6,7,3, POSITIVE);

void setup() 

{ 

      pinMode(trig, OUTPUT);

      pinMode(echo, INPUT);

      pinMode(buzzer,OUTPUT);

      lcd.begin (16,2); 

} 

void loop() 

{ 

      digitalWrite(trig, HIGH);

      delay(15);

      digitalWrite(trig, LOW);

      zaman = pulseIn(echo, HIGH); // Ses Dönüş Zamanı - time to echo 

      cm = zaman / 58;  //cm hesabı - time to centimetres

      inc=zaman/148;    //inç hesabı - time to inches

      

    // cm olarak mesafeyi LCD ekrana Yazdırmak- Distance in cm on LCD

      lcd.setCursor(0,0);  

      lcd.print("cm :"); 

      lcd.setCursor(4,0); 

      lcd.print(cm); 

    // inç olarak mesafeyi LCD ekrana Yazdırmak- Distance in inch on LCD 

      lcd.setCursor(0,1);  

      lcd.print("inc:"); 

      lcd.setCursor(4,1); 

      lcd.print(inc); 

    //cm ile Buzzer ile mesafe kontrolü - Distance control with buzzer in cm

      if( cm>10)

       {

          noTone(buzzer);

        }

       if( cm<=10)

       {

          tone(buzzer, 500,100);

        }

       if( cm<=5)

        {

          tone(buzzer, 500,1000);

         }

     delay(500);

}

Project Files
You can download project files by clickin the links.

• Arduino UNO Program mesafe.ino
• LiquidCrystal_I2C.h

Video Of Lesson