Blind Walking Stick Using Arduino & Ultrasonic Sensor HC-SR04

Blind Walking Stick Using Arduino & Ultrasonic Sensor HC-SR04 (Last Updated On: November 21, 2018)

Blind Walking Stick Using Arduino & Ultrasonic Sensor HC-SR04:

In this project we will learn how to design Blind Walking Stick Using Arduino & Ultrasonic Sensor HC-SR04. Almost 30 million people are blind according to recent WHO Report. These blind people are totally dependent on others as they can’t walk alone. This is the reason why we have designed Blind Walking Stick device which will help blind people to walk with ease independently. For better accuracy and assistance two or three Ultrasonic Sensors sensors can be added to this project.


Components Required:

1. Arduino UNO Board
2. HC-SR04 Ultrasonic Sensor
3. Buzzer
4. 9 Volt Battery
5. Switch (Optional)

Circuit Diagram & Connections:

To design Blind Walking Stick Using Arduino & Ultrasonic Sensor HC-SR04, make the following connections as shown in the connection diagram below.

Blind Walking Stick Using Arduino & Ultrasonic Sensor HC-SR04


1. Vcc pin of HC-SR04 is connected to 5 volt pin of Arduino
2. Trigger pin of HC-SR04 is connected to D12 pin of Arduino
3. Echo pin of HC-SR04 is connected to D11 pin of Arduino
4. Ground of HC-SR04 is connected to GND pin of Arduino.
5. Positive terminal of 9-volt battery is connected to Vin pin of Arduino and the negative terminal is connected to GND pin of Arduino.
6. A buzzer is connected between D9 pin of Arduino and GND pin.


Circuit & Working:

The main objective of this project is to help blind people to walk with ease and to be warned whenever their walking path is obstructed with obstacles. As a warning signal via buzzer, whose frequency of beep changes according to the distance of object. The closer the distance of obstruction, the more will be the buzzer beep frequency.

The main component used for this device is the Ultrasonic Sensor HC-SR04. The ultrasonic sensor transmits a high frequency sound pulse and then calculates the time to receive the signal of the sound echo to reflect back. HC-SR04 has transmitter & receiver surface. One of them acts as the transmitter and transmits the ultrasonic waves. The other one acts as a receiver and receives the echoed sound signal. The sensor is calibrated according to the speed of the sound in air. The speed of sound is 341 meter per second in the air, and the distance between sensor and object is equal to time multiplied by speed of sound divided by two.

Distance = (Time * Speed Of Sound) รท 2




After the distance measurement, Arduino makes a beep format using buzzer, when distance is high, frequency of beep is decreased and beep frequency is increased when distance is low.


Source Code/Program:

First download the Ultrasonic Sensor Library <Ultrasonic.h&gt from here and add the library to Arduino IDE. Then compile and upload.
Download <Ultrasonic.h&gt library

int buzzer = 9;

#include <Ultrasonic.h>

Ultrasonic ultrasonic(12,11);

void setup() {
Serial.begin(9600);
pinMode(buzzer,OUTPUT);
}

void loop()
{
int distance = ultrasonic.Ranging(CM);
if (distance<50){
int dil = 2*distance;

digitalWrite(buzzer,HIGH);
delay(dil);
digitalWrite(buzzer,LOW);
delay(dil);
}
}

Video Tutorial & Explanation:

Coming Soon




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