#define left_line 6
#define right_line 7
#define M11 4
#define M12 5
#define M21 8
#define M22 9
pinMode(12, OUTPUT);
pinMode(13, INPUT);
void setup() {


Serial.begin(9600);
}

void loop() {
delay(300);
int l = digitalRead(left_line);
int r = digitalRead(right_line);


Serial.println(r);
Serial.println(l);

if (r == 0 && l == 0){Forward(150);}

if (r == 1 && l == 0){Left(150);}

if (r == 0 && l == 1){Right(150);}

if (r == 1 && l == 1){Forward(150);}
}
void Forward(int Speed){
  analogWrite(M12,LOW);
  analogWrite(M21,Speed);
  analogWrite(M11,Speed);
  analogWrite(M22,LOW);
}

void Back(int Speed){
  analogWrite(M12,Speed);
  analogWrite(M21,LOW);
  analogWrite(M11,LOW);
  analogWrite(M22,Speed);
}

void Left(int Speed){
  analogWrite(M12,LOW);
  analogWrite(M21,LOW);
  analogWrite(M11,Speed);
  analogWrite(M22,Speed);
}

void Right(int Speed){
  analogWrite(M12,Speed);
  analogWrite(M21,Speed);
  analogWrite(M11,LOW);
  analogWrite(M22,LOW);
}

void Stop(){
  analogWrite(M12,LOW);
  analogWrite(M21,LOW);
  analogWrite(M11,LOW);
  analogWrite(M22,LOW);
}