const int EnableL = 5;
const int HighL = 7;       // LEFT SIDE MOTOR
const int LowL =6;

const int EnableR = 10;
const int HighR = 8;       //RIGHT SIDE MOTOR
const int LowR =9;

const int D0 = 0;       //Raspberry pin 21    LSB
const int D1 = 1;       //Raspberry pin 22
const int D2 = 2;       //Raspberry pin 23
const int D3 = 3;       //Raspberry pin 24    MSB

int a,b,c,d,data;


void setup() {

pinMode(EnableL, OUTPUT);
pinMode(HighL, OUTPUT);
pinMode(LowL, OUTPUT);


pinMode(EnableR, OUTPUT);
pinMode(HighR, OUTPUT);
pinMode(LowR, OUTPUT);

pinMode(D0, INPUT_PULLUP);
pinMode(D1, INPUT_PULLUP);
pinMode(D2, INPUT_PULLUP);
pinMode(D3, INPUT_PULLUP);


}

void Data()
{
   a = digitalRead(D0);
   b = digitalRead(D1);
   c = digitalRead(D2);
   d = digitalRead(D3);

   data = 8*d+4*c+2*b+a;
}

void Forward()
{
  digitalWrite(HighL, LOW);
  digitalWrite(LowL, HIGH);
  analogWrite(EnableL,180);

  digitalWrite(HighR, LOW);
  digitalWrite(LowR, HIGH);
  analogWrite(EnableR,180);
  
}


void Backward()
{
  digitalWrite(HighL, HIGH);
  digitalWrite(LowL, LOW);
  analogWrite(EnableL,255);

  digitalWrite(HighR, HIGH);
  digitalWrite(LowR, LOW);
  analogWrite(EnableR,255);
  
}

void Stop()
{
  digitalWrite(HighL, LOW);
  digitalWrite(LowL, HIGH);
  analogWrite(EnableL,0);

  digitalWrite(HighR, LOW);
  digitalWrite(LowR, HIGH);
  analogWrite(EnableR,0);
  
}

void Left1()
{
  digitalWrite(HighL, LOW);
  digitalWrite(LowL, HIGH);
  analogWrite(EnableL,160);

  digitalWrite(HighR, LOW);
  digitalWrite(LowR, HIGH);
  analogWrite(EnableR,255);
  
}

void Left2()
{
  digitalWrite(HighL, LOW);
  digitalWrite(LowL, HIGH);
  analogWrite(EnableL,90);

  digitalWrite(HighR, LOW);
  digitalWrite(LowR, HIGH);
  analogWrite(EnableR,255);
  
}


void Left3()
{
  digitalWrite(HighL, LOW);
  digitalWrite(LowL, HIGH);
  analogWrite(EnableL,50);

  digitalWrite(HighR, LOW);
  digitalWrite(LowR, HIGH);
  analogWrite(EnableR,255);
  
}

void Right1()
{
  digitalWrite(HighL, LOW);
  digitalWrite(LowL, HIGH);
  analogWrite(EnableL,255);

  digitalWrite(HighR, LOW);
  digitalWrite(LowR, HIGH);
  analogWrite(EnableR,160);  //200
  
}
void Right2()
{
  digitalWrite(HighL, LOW);
  digitalWrite(LowL, HIGH);
  analogWrite(EnableL,255);

  digitalWrite(HighR, LOW);
  digitalWrite(LowR, HIGH);
  analogWrite(EnableR,90);   //160
  
}

void Right3()
{
  digitalWrite(HighL, LOW);
  digitalWrite(LowL, HIGH);
  analogWrite(EnableL,255);

  digitalWrite(HighR, LOW);
  digitalWrite(LowR, HIGH);
  analogWrite(EnableR,50);   //100
  
}

void UTurn()
{
  analogWrite(EnableL, 0);
  analogWrite(EnableR, 0);
  delay(400);

  analogWrite(EnableL, 250);
  analogWrite(EnableR, 250);    //forward
  delay(1000);

  analogWrite(EnableL, 0);
  analogWrite(EnableR, 0);
  delay(400);

  digitalWrite(HighL, HIGH);
  digitalWrite(LowL, LOW);
  digitalWrite(HighR, LOW);   //   left
  digitalWrite(LowR, HIGH);
  analogWrite(EnableL, 255);
  analogWrite(EnableR, 255);
  delay(700);

  analogWrite(EnableL, 0);
  analogWrite(EnableR, 0);
  delay(400);

  digitalWrite(HighL, LOW);
  digitalWrite(LowL, HIGH);
  digitalWrite(HighR, LOW);   // forward
  digitalWrite(LowR, HIGH);
  analogWrite(EnableL, 255);
  analogWrite(EnableR, 255);
  delay(900);

  analogWrite(EnableL, 0);
  analogWrite(EnableR, 0);
  delay(400);

  digitalWrite(HighL, HIGH);
  digitalWrite(LowL, LOW);
  digitalWrite(HighR, LOW);    //left
  digitalWrite(LowR, HIGH);
  analogWrite(EnableL, 255);
  analogWrite(EnableR, 255);
  delay(700);


  analogWrite(EnableL, 0);
  analogWrite(EnableR, 0);
  delay(1000);



  digitalWrite(HighL, LOW);
  digitalWrite(LowL, HIGH);
  digitalWrite(HighR, LOW);
  digitalWrite(LowL, HIGH);
  analogWrite(EnableL, 150);
  analogWrite(EnableR, 150);
  delay(300);
}



void loop() 
{
  Data();
  if(data==0)
   {
     Forward();
   }
   
  else if(data==1)
   {
     Right1();
   }
     
  else if(data==2)
   {
     Right2();
   }
     
  else if(data==3)
   {
     Right3();
   }
     
  else if(data==4)
   {
     Left1();
   }
    
  else if(data==5)
   {
     Left2();
   }
    
  else if(data==6)
   {
     Left3();
   }
  
  else if (data==7)
   {
     Stop();
     delay(5000);
   }
    
   else if (data==8)
   {
      analogWrite(EnableL, 0);
      analogWrite(EnableR, 0);
      delay(4000);                      // stop sign detection

      analogWrite(EnableL, 150);
      analogWrite(EnableR, 150);
      delay(1000);
   }

     else if(data>8)
   {
     Stop();
   }



}