int E1 = 5; //E1 pin  --  links
int M1 = 4; //M1 pin  --  links
int E2 = 2; //E2 pin  --  rechts
int M2 = 3; //M2 pin  --  rechts

int trackLPin = 15;
int trackRPin = 14;

boolean trackL = false;
boolean trackR = false;

int velocity = 100;

void setup()
{
        pinMode(M1, OUTPUT);
        pinMode(M2, OUTPUT);
        Serial.begin(9600);
        pinMode(trackLPin, INPUT);
        pinMode(trackRPin, INPUT);
}

void loop ()
{

    forward(velocity);
   /*initLinetrack();
   Serial.print(trackR);
   Serial.println(trackL);

        while (trackR == true && trackL == true)
        {
            initLinetrack();
            forward(velocity);
        }

        while (trackR == false && trackL == false)
        {
            initLinetrack();
            corner(1, 50, 150);
        }

        while (trackR == true && trackL == false)
        {
            initLinetrack();
            corner(0, 20, 150);
        }

        while (trackR == false && trackL == true)
        {
            initLinetrack();
            corner(1, 20, 150);
        }
        */
}

void initLinetrack()
{
        trackL = (boolean)digitalRead(trackLPin);
        trackR = (boolean)digitalRead(trackRPin);
}

void forward (int velocityThis)
{
        digitalWrite(M1, HIGH); //Drehrichtung
        digitalWrite(M2, HIGH); // Drehrichtung
        analogWrite(E1, velocityThis); // PWM Speed Control
        analogWrite(E2, velocityThis); //mit analogWrite werden PWM-Signale angegeben
}
void stopp (int duration)
{
        digitalWrite(M1, LOW); //Drehrichtung
        digitalWrite(M2, HIGH); // Drehrichtung
        analogWrite(E1, 0); // PWM Speed Control
        analogWrite(E2, 0); //mit analogWrite werden PWM-Signale angegeben
        delay(duration);
}

void corner (int dir, int duration, int g)
{
        if (dir == 0)       //links
        {
            digitalWrite(M1, LOW);
            digitalWrite(M2, LOW);
            analogWrite(E1, 0);
            analogWrite(E2, g);
        }
        else if (dir == 1)   //rechts
        {
            digitalWrite(M1, HIGH);
            digitalWrite(M2, HIGH);
            analogWrite(E1, g);
            analogWrite(E2, 0);
        }

        delay(2.5 * duration);
}