How To Make a Simple Autonomous Robot

**Updates: wiring diagram,
                  step by step tutorial
         
Tutorial:
    This is a simple autonomous robot which you can make easily at home without much experience of electronics and coding.  It works on the principle of echolocation using the SONAR. The ultrasound sensor is used for detecting the obstacle. It basically moves around and if it detects any obstacles in its path it will avoid and find its way out.

List of components with Estimated price in INR:
    1. Arduino: Any arduino will do- Arduino UNO, Nano, Mega, Mini, Micro etc.
         (Estimated Rs. 500)
    2. Ping Sensor/ ultrasound sensor: HC SR-04
         (estimated Rs. 150)
    3. Servo motor: Micro Servo motor SG90/ MG90
         (estimated price Rs.300)
    4. BO motor 60-150 RPM two pieces
        (estimated price Rs. 300)
        **please select motor RPM of not more then 150 RPM because it becomes unstable.
    6. BO motor wheel two pieces
        (estimated price Rs.150)
    7. Motor Driver: L298 motor driver
       (estimated Price Rs.250)
    8. Castor Wheel
       (Estimated Price Rs.100)
     9. Jumper Wire:
       (Estimated Price Rs. 100)
     10. Battery: 12V
         (you can buy a rechargeable or you can run from AA/AAA batteries by connecting them in series to obtain 12 volts. But I suggest you buy a rechargeable one because its a pain in the ass to buy a new dry cell every time.)
          (estimated cost: depends upon what you choose: Rs. 80- 1000
     10. Chasis: You can buy a ready made or you can make one of your own like I did.
          ( in case you buy Estimated: Rs. 150)

Now once you have all the above materials you are ready to go.

Watch the tutorial Video  and SUBSCRIBE to my channel or continue reading.

Steps:
1. First of all plan how you want the robot to look. It may be very simple or nice looking like Wall-E.
2. Solder all the terminals of the motors and sensors. you can connect them with jumper wire too.
3. once the soldering is done, place all the components in their places. I don't have any idea how you want to and where you wish to place them but I suppose you have plan it well.
4. Next connect all the wires All GND to Common. And other wires to their designated place.
5. Upload the codes and make a test run.
** if the motor seems to spin in opposite directions, just reverse the wire of the motor.
**if the turning of the robot is not very efficient adjust the delay of the motor on time on the code.
**in case you motor is of high RPM and you want the robot to move a bit slower, adjust the PWM output.
the wiring diagram is given below.


IF YOU NEED ANY HELP COMMENT IN THE YOUTUBE COMMENT SECTION.

Wiring Diagram


____________________________
New Ping Library, Download from here →
https://playground.arduino.cc/Code/NewPing


The codes for the robot:

Please copy the codes after the line and paste it directly.

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//This is the code for the robot                                        

// make sure to  include the NewPing and Servo Libraries  before uploading else it will show error

#include <NewPing.h> 

#include <Servo.h>   

#define TRIG_PIN A4  

#define ECHO_PIN A5  

#define MAX_DISTANCE 200  

NewPing sonar(TRIG_PIN, ECHO_PIN, MAX_DISTANCE);  

Servo myservo;     

boolean goesForward=false; 

int distance = 100; 

int speedSet = 0;  

const int motorPin1  = 11;   

const int motorPin2  = 10;   

//Motor B 

const int motorPin3  = 6;  

const int motorPin4  = 5;    

void setup() {  

  myservo.attach(9);   

  myservo.write(115);  

  delay(2000); 

  distance = readPing(); 

  delay(100); 

  distance = readPing(); 

  delay(100); 

  distance = readPing(); 

  delay(100); 

  distance = readPing(); 

  delay(100); 

}  

void loop() { 

 int distanceR = 0; 

 int distanceL =  0; 

 delay(40); 

  

 if(distance<=20) 

 { 

  moveStop(); 

  delay(100); 

  moveBackward(); 

  delay(600); 

  moveStop(); 

  delay(200); 

  distanceR = lookRight(); 

  delay(200); 

  distanceL = lookLeft(); 

  delay(200);  

  if(distanceR>=distanceL) 

  { 

    turnRight(); 

    moveStop(); 

  }else 

  { 

    turnLeft(); 

    moveStop(); 

  } 

 }else 

 { 

  moveForward(); 

 } 

 distance = readPing(); 

}  

int lookRight() 

{ 

    myservo.write(50);  

    delay(500); 

    int distance = readPing(); 

    delay(100); 

    myservo.write(115);  

    return distance; 

}  

int lookLeft() 

{ 

    myservo.write(170);  

    delay(500); 

    int distance = readPing(); 

    delay(100); 

    myservo.write(115);  

    return distance; 

    delay(100); 

}  

int readPing() {  

  delay(70); 

  int cm = sonar.ping_cm(); 

  if(cm==0) 

  { 

    cm = 250; 

  } 

  return cm; 

}  

void moveStop() { 

  analogWrite(motorPin1, 0); 

    analogWrite(motorPin2, 0); 

    analogWrite(motorPin3, 0); 

    analogWrite(motorPin4, 0); 

  }  

   

void moveForward() {   

    analogWrite(motorPin1, 230);
 //the value 230 here is a PWM so you can change it depending up on your motor speed

    analogWrite(motorPin2, 0); 

    analogWrite(motorPin3, 230);
 // this one too is the PWM for other motor

    analogWrite(motorPin4, 0);   

   

}  

void moveBackward() { 

     

    analogWrite(motorPin1, 0); 

    analogWrite(motorPin2, 230);

    analogWrite(motorPin3, 0); 

    analogWrite(motorPin4, 230);    

   

}    

void turnRight() { 

 analogWrite(motorPin1, 240); 

    analogWrite(motorPin2, 0); 

  analogWrite(motorPin3, 0); 

    analogWrite(motorPin4, 230);     

  delay(1200); 

 moveForward();       

   

}  

  

void turnLeft() { 

  analogWrite(motorPin1, 0); 

    analogWrite(motorPin2, 240);    

 analogWrite(motorPin3, 240); 

    analogWrite(motorPin4, 0);      

  delay(800); 

   moveForward(); 

}


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