/*read line folloe sensors*/
void read_sensor_values()
{
  sensor[0]=digitalRead(LFSensor_0);
  sensor[1]=digitalRead(LFSensor_1);
  sensor[2]=digitalRead(LFSensor_2);
  sensor[3]=digitalRead(LFSensor_3);
  sensor[4]=digitalRead(LFSensor_4);
}

//Automatic tracking
void auto_tarcking(){
  read_sensor_values();
  if(sensor[2]==HIGH){ //The middle sensor is on the black line
    if(sensor[1]==LOW && sensor[3]==LOW){ //Other sensors are in the white area
      go_Advance();  //straight
      set_Motorspeed(LF_SPEED2,LF_SPEED2);
    }
    else if(sensor[1]==HIGH && sensor[3]==LOW){ //The second sensor is also on the black line
       go_Left();  //Turn left
       set_Motorspeed(0,LF_SPEED2);
    }
    else if(sensor[1]==LOW && sensor[3]==HIGH){  //The fourth sensor is also on the black line
      go_Right();  //Turn right
      set_Motorspeed(LF_SPEED2,0);
    }
  }
  else if(sensor[2]==LOW){  //The middle sensor is in the white area
    if(sensor[1]==HIGH && sensor[3]==LOW){ //Turn left
      go_Left();  
      set_Motorspeed(0,LF_SPEED2);
    }
    else if(sensor[1]==LOW && sensor[3]==HIGH){  //Turn right
       go_Right();
       set_Motorspeed(LF_SPEED2,0);
    }
  }
  else {
     go_Back();
     set_Motorspeed(LF_SPEED2,LF_SPEED2);
  }
  if(sensor[1]==HIGH){  //The second sensor is on the black line
    if(sensor[0]==HIGH && sensor[2]==LOW){ //Accelerate left turn
      go_Left();
      set_Motorspeed(0,LF_SPEED2);
    }
    else{  //Turn left
      go_Left();
      set_Motorspeed(0,LF_SPEED2);
    }
  }
  if(sensor[3]==HIGH){  //The fourth sensor is on the black line
    if(sensor[2]==LOW && sensor[4]==HIGH){  //Accelerate right turn
      go_Right();
      set_Motorspeed(LF_SPEED2,0);
    }
    else{  //Turn right
      go_Right();
      set_Motorspeed(LF_SPEED2,0);
    }
  }
}