├── Diagrams
    └── LineFollwerRobot.png
├── LICENSE
├── LineFollowerRobot
    └── LineFollowerRobot.ino
└── README.md


/Diagrams/LineFollwerRobot.png:
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https://raw.githubusercontent.com/un0038998/LineFollowerRobot/ed1202f7e7e88c642b585218aa7c5e14ea0653f8/Diagrams/LineFollwerRobot.png


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/LICENSE:
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 1 | MIT License
 2 | 
 3 | Copyright (c) 2021 Ujwal Nandanwar
 4 | 
 5 | Permission is hereby granted, free of charge, to any person obtaining a copy
 6 | of this software and associated documentation files (the "Software"), to deal
 7 | in the Software without restriction, including without limitation the rights
 8 | to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 9 | copies of the Software, and to permit persons to whom the Software is
10 | furnished to do so, subject to the following conditions:
11 | 
12 | The above copyright notice and this permission notice shall be included in all
13 | copies or substantial portions of the Software.
14 | 
15 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 | IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 | AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 | LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 | OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21 | SOFTWARE.
22 | 


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/LineFollowerRobot/LineFollowerRobot.ino:
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  1 | #define IR_SENSOR_RIGHT 11
  2 | #define IR_SENSOR_LEFT 12
  3 | #define MOTOR_SPEED 180
  4 | 
  5 | //Right motor
  6 | int enableRightMotor=6;
  7 | int rightMotorPin1=7;
  8 | int rightMotorPin2=8;
  9 | 
 10 | //Left motor
 11 | int enableLeftMotor=5;
 12 | int leftMotorPin1=9;
 13 | int leftMotorPin2=10;
 14 | 
 15 | void setup()
 16 | {
 17 |   //The problem with TT gear motors is that, at very low pwm value it does not even rotate.
 18 |   //If we increase the PWM value then it rotates faster and our robot is not controlled in that speed and goes out of line.
 19 |   //For that we need to increase the frequency of analogWrite.
 20 |   //Below line is important to change the frequency of PWM signal on pin D5 and D6
 21 |   //Because of this, motor runs in controlled manner (lower speed) at high PWM value.
 22 |   //This sets frequecny as 7812.5 hz.
 23 |   TCCR0B = TCCR0B & B11111000 | B00000010 ;
 24 |   
 25 |   // put your setup code here, to run once:
 26 |   pinMode(enableRightMotor, OUTPUT);
 27 |   pinMode(rightMotorPin1, OUTPUT);
 28 |   pinMode(rightMotorPin2, OUTPUT);
 29 |   
 30 |   pinMode(enableLeftMotor, OUTPUT);
 31 |   pinMode(leftMotorPin1, OUTPUT);
 32 |   pinMode(leftMotorPin2, OUTPUT);
 33 | 
 34 |   pinMode(IR_SENSOR_RIGHT, INPUT);
 35 |   pinMode(IR_SENSOR_LEFT, INPUT);
 36 |   rotateMotor(0,0);   
 37 | }
 38 | 
 39 | 
 40 | void loop()
 41 | {
 42 | 
 43 |   int rightIRSensorValue = digitalRead(IR_SENSOR_RIGHT);
 44 |   int leftIRSensorValue = digitalRead(IR_SENSOR_LEFT);
 45 | 
 46 |   //If none of the sensors detects black line, then go straight
 47 |   if (rightIRSensorValue == LOW && leftIRSensorValue == LOW)
 48 |   {
 49 |     rotateMotor(MOTOR_SPEED, MOTOR_SPEED);
 50 |   }
 51 |   //If right sensor detects black line, then turn right
 52 |   else if (rightIRSensorValue == HIGH && leftIRSensorValue == LOW )
 53 |   {
 54 |       rotateMotor(-MOTOR_SPEED, MOTOR_SPEED); 
 55 |   }
 56 |   //If left sensor detects black line, then turn left  
 57 |   else if (rightIRSensorValue == LOW && leftIRSensorValue == HIGH )
 58 |   {
 59 |       rotateMotor(MOTOR_SPEED, -MOTOR_SPEED); 
 60 |   } 
 61 |   //If both the sensors detect black line, then stop 
 62 |   else 
 63 |   {
 64 |     rotateMotor(0, 0);
 65 |   }
 66 | }
 67 | 
 68 | 
 69 | void rotateMotor(int rightMotorSpeed, int leftMotorSpeed)
 70 | {
 71 |   
 72 |   if (rightMotorSpeed < 0)
 73 |   {
 74 |     digitalWrite(rightMotorPin1,LOW);
 75 |     digitalWrite(rightMotorPin2,HIGH);    
 76 |   }
 77 |   else if (rightMotorSpeed > 0)
 78 |   {
 79 |     digitalWrite(rightMotorPin1,HIGH);
 80 |     digitalWrite(rightMotorPin2,LOW);      
 81 |   }
 82 |   else
 83 |   {
 84 |     digitalWrite(rightMotorPin1,LOW);
 85 |     digitalWrite(rightMotorPin2,LOW);      
 86 |   }
 87 | 
 88 |   if (leftMotorSpeed < 0)
 89 |   {
 90 |     digitalWrite(leftMotorPin1,LOW);
 91 |     digitalWrite(leftMotorPin2,HIGH);    
 92 |   }
 93 |   else if (leftMotorSpeed > 0)
 94 |   {
 95 |     digitalWrite(leftMotorPin1,HIGH);
 96 |     digitalWrite(leftMotorPin2,LOW);      
 97 |   }
 98 |   else 
 99 |   {
100 |     digitalWrite(leftMotorPin1,LOW);
101 |     digitalWrite(leftMotorPin2,LOW);      
102 |   }
103 |   analogWrite(enableRightMotor, abs(rightMotorSpeed));
104 |   analogWrite(enableLeftMotor, abs(leftMotorSpeed));    
105 | }
106 | 


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/README.md:
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1 | # LineFollowerRobot
2 | This repository contains code and diagram for Line Follower Robot using Arduino
3 | 


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