Published November 27, 2019 © GPL3+

Blind Man's Stick

The project makes use of an Arduino Uno and Nano to alert the blind man of an obstacle and a joystick to tell about the surroundings.

IntermediateProtip3 hours1,287

Things used in this project

Hardware components

Arduino Nano R3

Arduino UNO

Ultrasonic Sensor - HC-SR04 (Generic)

SG90 Micro-servo motor

Analog joystick (Generic)

Story

The project was a simple idea that I developed for a small workshop/competition in Semester 2 (January 2018).

The idea was developed around 2 boards i.e. Arduino Uno & Nano.

The Uno board ran the code for calculating the distance using an HC-SR04 (ultrasonic sensor) based on which it triggered a buzzer and the frequency of the buzzer would increase when the blind person approaches closer to the obstacle.

The Nano board had 2 goals :

Power the Arduino Board using its 5V supply.
To run the code for moving (sweeping) the servo motor on which the ultrasonic sensor was mounted and the I/p to the servo was given by a joystick module controlled by the blind person.

The reason why I ran the code 2 separate boards is because of the clock cycles wasted by calling an ultrasonic sensor routine for distance measurement made it very difficult for all other modules such as servo, joystick and buzzer to synchronise. When I ran the code on a single board for all the specified modules, the O/p was sometimes not accurate or it took too long for the practical application.

The idea that I had in mind was, that the ultrasonic sensor would detect the obstacle and trigger the buzzer for alert and the joystick would be used by the blind person to sweep an angle 0f 180 degrees to find wether there are any more obstacles in the vicinity.

const byte trig=9,echo=8,buzz=2,check_pin=3;
long duration=0;
int distance=0;
void setup() {
  pinMode(trig,OUTPUT);                 //trigger pin for usonic
  pinMode(echo,INPUT);                  //echo    pin for usonic
  pinMode(buzz,OUTPUT);                 //buzzer pin
  pinMode(check_pin,INPUT);
  Serial.begin(9600);
}
int getdis()
{
 digitalWrite(trig,LOW);
 delayMicroseconds(2);
 digitalWrite(trig,HIGH);
 delayMicroseconds(10); 
 digitalWrite(trig,LOW);
 distance=pulseIn(echo,HIGH)*(0.034/2);
 return distance;
}
void loop() {
 if(digitalRead(check_pin)==HIGH)
 { 
  int di=getdis();
  while(di>=70)
   di=getdis();
  while(di<70 && di>50)
  {
    tone(buzz,3000,300);
    delay(3000);
    di=getdis();
  }
  while(di<=50 && di>30)
  {
    tone(buzz,3000,300);
    delay(1000);
    di=getdis();
  }
  while(di<=30)
  {
    tone(buzz,3000,300);
    delay(500);
    di=getdis();
  }  
 }
}

#include <Servo.h>
Servo serv;
const byte s=3,x=A0,ok_sw=2,check_pin=4;
int xmin=1023,xmax=0;
void setup()
{ 
 int swit=1;
//*****************************************************************************
 
 pinMode(x,INPUT);                     //X axis input of joystick
 pinMode(s,OUTPUT);                    //pin for servo signal
 pinMode(ok_sw,INPUT);                 //push_button on joystick
 digitalWrite(ok_sw,HIGH);             //push_button is an input button but we give it a reference point to understand wether on pushing to go to high or low(our case it goes to low)
 pinMode(check_pin,OUTPUT);
 digitalWrite(check_pin,LOW);
//*****************************************************************************
 
 serv.attach(s);                       //creating an object of class Servo
 serv.write(90);                       //calibrating servo to 90 degrees.
 
//*****************************************************************************
 
 Serial.begin(9600);
 
//**************Calibration___Routine******************************************
//The joystick is an actuator therefore the extreme end points of x values may keep on changing time to time
//Therefore through this routine we aim to calibrate the whole setup and find max and min x's analog values and that range would be mapped to (45 deg to 135 deg)
//45 to 135 deg is choosen because the servo I am using , can sustain the load greater than these angles.
 
 Serial.println("Please move your joystick to extreme left and press okay");
 while(swit==1)
 {
  int tmp=analogRead(x);
  if(xmin>tmp)                  //to get the min value before pressing button
   xmin=tmp;
  swit=digitalRead(ok_sw);
  Serial.println(swit);
  Serial.println(xmin);
  delay(100);
 }
 swit=1;
 delay(500);
 Serial.println("Please move your joystick to extreme right and press okay");
 while(swit==1)
 {
  int tmp=analogRead(x);
  if(xmax<tmp)                 //to get the max value before pressing button
   xmax=tmp;
  swit=digitalRead(ok_sw);
  Serial.println(swit);
  Serial.println(xmax);
  delay(100);
  digitalWrite(check_pin,HIGH);
 }
//Voice support will be added to make the blind guy understand where to move joystick
//*******************************************************************************
}
void rotate()
{
  int xval=analogRead(x);
  xval=map(xval,xmax,xmin,55,110);
  serv.write(xval);
  Serial.println(xval);
}

void loop()
{
 rotate();
 delay(300);
}

Credits

vedrocks15

5 projects • 5 followers

Blind Man's Stick

Things used in this project

Hardware components

Story

Code

Arduino Uno

Arduino Nano

Credits

vedrocks15

Comments

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Blind Man's Stick

Blind Man's Stick

Things used in this project

Hardware components

Story

Code

Arduino Uno

Arduino Nano

Credits

vedrocks15

Comments

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