Building An Obstacle-Avoiding Robot

Introduction

 

This article will help those who are interested in learning the Internet of Things. It gives brief details of Arduino and Ultrasonic sensors which are used to detect a collision.

 

Requirements

• Arduino Uno
• Ultrasonic sensors
• Servo motor
• DC motors
• Chaises board
• Jumper wires
• L293D motor driver
• Battery

Steps to follow.

 

Step 1

 

First of all, connect the Arduino board with a laptop or computer.

 

 

Step 2

 

Install the Arduino software on the computer.

 

       

 

Step 3

 

Open the Arduino software. The following screen will appear.

 

 

Step 4

 

You can see the Main Page of the software.

 

  

 

Step 5

 

Then, open the new page on the software.

 

Then select the File→ New.

 

 

A new page opens on the Arduino software.

 

 

Step 6

 

I have given a source code that you can use or you can use your own source code.

 

Then, select File → open → select written program →open the program.

 

 

 

Open the program folder.

 

 

Select the program and open it.

 

 

Source code

#include <Servo.h>
#include <NewPing.h>
const int LeftMotorForward = 7;
const int LeftMotorBackward = 6;
const int RightMotorForward = 4;
const int RightMotorBackward = 5;
#define trig_pin A1 //analog input 1
#define echo_pin A2 //analog input 2
#define maximum_distance 200
 boolean goesForward= false;
 int distance = 100;

 NewPing sonar(trig_pin,echo_pin, maximum_distance); //sensor function
 Servo servo_motor;//our servo name

 void setup(){
  Serial.begin(9600);
   pinMode(RightMotorForward,OUTPUT);
   pinMode(LeftMotorForward,OUTPUT);
   pinMode(LeftMotorBackward,OUTPUT);
   pinMode(RightMotorBackward,OUTPUT);

   servo_motor. attach(10);//our servo pin
   servo_motor.write(115);
   delay(2000);
   distance =readPing();
   delay(100);
   distance = readPing();
   delay(100);
   distance =readPing();
   delay(100);
   distance = readPing();
   delay(100);

 }
  void loop(){
    int distanceRight = 0;
    int distanceLeft = 0;
    delay(50);

   if(distance<=40){
    //Serial.println(distance);
     moveStop();
     delay(400);
     moveBackward();
     delay(400);
     moveStop();
     delay(400);
     distanceRight = lookRight();
     delay(400);
     distanceLeft = lookLeft();
     delay(400);

     if(distance >= distanceLeft){
     turnRight();
     moveStop();
     }
     else{
      turnLeft();
      moveStop();
     }
     }
     else{
      moveForward();
        }
      distance = readPing();
      }

      int lookRight(){

        servo_motor.write(50);
        delay(500);
        int distance=readPing();
        delay(100);
        servo_motor.write(115);
        return distance;

      }

      int lookLeft(){
        servo_motor.write(170);
        delay(500);
        int distance = readPing();
        delay(100);
        servo_motor.write(115);
        return distance;
        delay(100);
        }
        int readPing(){
          delay(70);
          int cm = sonar.ping_cm();
          if (cm==0){
            cm=250;
          }
          return cm;
        }
        void moveStop(){

          digitalWrite(RightMotorForward,LOW);
          digitalWrite(LeftMotorForward,LOW);
          digitalWrite(RightMotorBackward,LOW);
          digitalWrite(LeftMotorBackward,LOW);
          }
    void moveForward(){
      if(!goesForward){
        goesForward=true;

        digitalWrite(LeftMotorForward,HIGH);
        digitalWrite(RightMotorForward,HIGH);
        digitalWrite(LeftMotorBackward,LOW);
        digitalWrite(RightMotorBackward,LOW);

      }
    }
    void moveBackward(){
      goesForward=false;
      digitalWrite(LeftMotorBackward,HIGH);
      digitalWrite(RightMotorBackward,HIGH);
      digitalWrite(LeftMotorForward,LOW);
      digitalWrite(RightMotorForward,LOW);
      }
      void turnRight(){
        digitalWrite(LeftMotorForward,HIGH);
        digitalWrite(RightMotorBackward,HIGH);

        digitalWrite(LeftMotorBackward,LOW);
        digitalWrite(RightMotorForward,LOW);

        delay(500);

        digitalWrite(LeftMotorForward,HIGH);
        digitalWrite(RightMotorForward,HIGH);

        digitalWrite(LeftMotorBackward,LOW);
        digitalWrite(RightMotorBackward,LOW);

      }
 void turnLeft(){
    digitalWrite(LeftMotorBackward,HIGH);
    digitalWrite(RightMotorForward,HIGH);

    digitalWrite(LeftMotorForward,LOW);
    digitalWrite(RightMotorBackward,LOW);

    delay(500);

    digitalWrite(LeftMotorForward,HIGH);
     digitalWrite(RightMotorForward,HIGH);

      digitalWrite(LeftMotorBackward,LOW);
       digitalWrite(RightMotorBackward,LOW);
 }

Step 9

 

The obstacle avoiding robot program coding will be there already. The value of distance for the ultrasonic sensors to detect the collision is set in the program as 30 cm.

 

 

Step 10

 

Click TOOL-  Select BOARD - then press ARDUINO/GENUINO UNO R3.

 

 

Again Select TOOL >> Select a PORT >> COM3 ARDUINO UNO

 

 

Step 11

 

Verify the program or compile the program.

 

 

The compilation is done.

 

Step 12

 

Connect the hardware as per the connection diagram given for the Obstacle avoiding robot.

 

 

Complete the connection as per the diagram.

 

Step 13

 

Then connect the Arduino to the laptop and upload the code in Arduino.

 

 

Step 14

 

Then the obstacle avoiding robot will start working.

 

 

The ultrasonic sensor detects the collision using Arduino.

 

Summary

 

Hence, we have created and executed an Arduino project which prevents collisions with an obstacle avoiding robot.

 

More exciting articles are coming up next.