How to make a Security alarm using Arduino Uno with Ultra sonic sensor

 How to make a Security alarm using Arduino Uno with Ultra   sonic sensor 

Today we are going to make a another smart device  using Arduino Uno board with ultra sonic sensor. Now all of you know about Basic functions of  Arduino Uno board.

Then we will familiar to Ultrasonic sensor.

An ultrasonic sensor is an electronic device that measures the distance of a target object by emitting ultrasonic sound waves, and converts the reflected sound into an electrical signal. Ultrasonic waves travel faster than the speed of audible sound (i.e. the sound that humans can hear). Ultrasonic sensors have two main components: the transmitter (which emits the sound using piezoelectric crystals) and the receiver (which encounters the sound after it has travelled to and from the target).

In order to calculate the distance between the sensor and the object, the sensor measures the time it takes between the emission of the sound by the transmitter to its contact with the receiver. The formula for this calculation is D = ½ T x C (where D is the distance, T is the time, and C is the speed of sound ~ 343 meters/second). For example, if a scientist set up an ultrasonic sensor aimed at a box and it took 0.025 seconds for the sound to bounce back, the distance between the ultrasonic sensor and the box would be:

D = 0.5 x 0.025 x 343

or about 4.2875 meters.

Now we move to our Project which is "Security alarm using Arduino Uno with Ultra sonic sensor".

Components                                 Qty

Arduino Uno Board                          01

Breadboard                                 01

Jumper Cables                              08                             

The HC-SR04 ultrasonic sensor              01

LED                                        01

(you can get any color as you wish)

Active buzzer                                                                                  01

Circuit Diagram

1st step prepare a Arduino Uno board

Ultra sonic sensor has 4 pins. Name as vcc,trigger pin, echo pin, Ground pin. In this circuit vcc pin connect to 5v pin  in Arduino, And also other connectors are given below.

Ultrasonic sensor pins                  Arduino board pins(which                                              connect with Uno board)

vcc pin                                      5v pinn

Echo pin                                     Digital 10 Pin

Trigger pin                                  Digital 9  Pin 

Ground pin                                    GND pin

                                                    The real view of circuit 

2nd step prepare bread board

Now we should connect buzzer and ultra sonic sensor to bread board via male to male jumper cables.

3rd step Codding ant upload code  to Arduino board

Arduino 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 <= 20)   // You can change safe distance from here changing value Ex. 20 , 40 , 60 , 80 , 100, all in cm

{

  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);

}                    

Now execute your program and have a fun