#include <SoftwareSerial.h>
SoftwareSerial BT_Serial(2, 3); // RX, TX

#define enA 6//Enable1 Pin enA 
#define in1 7 //Motor1   Pin in1 

#define in4 8 //Motor2   Pin in1 
#define enB 9 //Enable2  Pin enB 

#define R_S A1 //ir sensor Right
#define L_S A0 //ir sensor Left

int bt_data; // variable to receive data from the serial port
int Speed = 0;  //pwm motors
int num = 350; // sensor value that limits the color white from black
int mode=0; 

void setup(){ 

pinMode(R_S, INPUT); // declare if sensor as input  
pinMode(L_S, INPUT); // declare ir sensor as input

pinMode(enA, OUTPUT); // declare as output for  Pin enA 
pinMode(in1, OUTPUT); // declare as output for  Pin in1 

pinMode(in4, OUTPUT); // declare as output for  Pin in4 
pinMode(enB, OUTPUT); // declare as output for  Pin enB 

Serial.begin(9600); // start serial communication at 9600bps
BT_Serial.begin(9600); 
delay(500);
}


void loop(){  
  
if(BT_Serial.available() > 0){  //if some date is sent, reads it and saves in state     
bt_data = BT_Serial.read();      
if(bt_data > 20){Speed = bt_data;}      
}

     if(bt_data == 8){mode=1; Speed=100;} //Auto Line Follower Command  
else if(bt_data == 9){mode=0; Stop(0);}    //Manual Android Application Control Command

if(mode==0){     
//===============================================================================
//                          Key Control Command
//=============================================================================== 
     if(bt_data == 1){forword(Speed); }  // if the bt_data is '1' the DC motor will go forward
else if(bt_data == 2){backword(Speed);}  // if the bt_data is '2' the motor will Reverse
else if(bt_data == 3){turnLeft(Speed);}  // if the bt_data is '3' the motor will turn left
else if(bt_data == 4){turnRight(Speed);} // if the bt_data is '4' the motor will turn right
else if(bt_data == 5){Stop(0); }     // if the bt_data '5' the motor will Stop


}else{    
//===============================================================================
//                          Line Follower Control
//===============================================================================     
if((analogRead(R_S) < num)&&(analogRead(L_S) < num)){forword(Speed);}  //if Right Sensor and Left Sensor are at White color then it will call forword function
if((analogRead(R_S) >= num)&&(analogRead(L_S) < num)){turnRight(Speed);}//if Right Sensor is Black and Left Sensor is White then it will call turn Right function  
if((analogRead(R_S) < num)&&(analogRead(L_S) >= num)){turnLeft(Speed);} //if Right Sensor is White and Left Sensor is Black then it will call turn Left function
if((analogRead(R_S) >= num)&&(analogRead(L_S) >= num)){Stop(0);}     //if Right Sensor and Left Sensor are at Black color then it will call Stop function
} 

delay(10);
}

//===========================================================================
//                          movements functions
//===========================================================================

void forword(int s){  //forword
analogWrite(enA, s); // Write The Duty Cycle 0 to 255 Enable Pin A for Motor1 Speed 
analogWrite(enB, s); // Write The Duty Cycle 0 to 255 Enable Pin B for Motor2 Speed 
digitalWrite(in1, HIGH); //Right Motor forword Pin 
digitalWrite(in4, HIGH); //Left Motor forword Pin 
}

void backword( int s){ //backword
analogWrite(enA, s); // Write The Duty Cycle 0 to 255 Enable Pin A for Motor1 Speed 
analogWrite(enB, s); // Write The Duty Cycle 0 to 255 Enable Pin B for Motor2 Speed 
digitalWrite(in1, LOW);  //Right Motor forword Pin 
digitalWrite(in4, LOW);  //Left Motor forword Pin 
}

void turnRight(int s){ //turnRight
analogWrite(enA, s); // Write The Duty Cycle 0 to 255 Enable Pin A for Motor1 Speed 
analogWrite(enB, s); // Write The Duty Cycle 0 to 255 Enable Pin B for Motor2 Speed 
digitalWrite(in1, LOW);  //Right Motor forword Pin 
digitalWrite(in4, HIGH); //Left Motor forword Pin 
}

void turnLeft(int s){ //turnLeftç
analogWrite(enA,s); // Write The Duty Cycle 0 to 255 Enable Pin A for Motor1 Speed 
analogWrite(enB,s); // Write The Duty Cycle 0 to 255 Enable Pin B for Motor2 Speed 
digitalWrite(in1, HIGH); //Right Motor forword Pin 
digitalWrite(in4, LOW);  //Left Motor forword Pin 
}

void Stop(int s){ //stop

analogWrite(enA, s); // Write The Duty Cycle 0 to 255 Enable Pin A for Motor1 Speed 
analogWrite(enB, s); // Write The Duty Cycle 0 to 255 Enable Pin B for Motor2 Speed 
digitalWrite(in1, LOW); //Right Motor forword Pin 
digitalWrite(in4, LOW); //Left Motor forword Pin 
}