int LeftMotorForward = 6; 
int LeftMotorReverse = 7; 
int RightMotorForward = 8;
int RightMotorReverse = 9;


const int sensorPin0 = A0;    // pin that the sensor is attached to
const int sensorPin1 = A1;    // pin that the sensor is attached to
const int ledPin = 13;        // pin that the LED is attached to

// variables:
int sensorValue0 = 0;         // the sensor value
int sensorMin0 = 1023;        // minimum sensor value
int sensorMax0 = 0;           // maximum sensor value


int sensorValue1 = 0;         // the sensor value
int sensorMin1 = 1023;        // minimum sensor value
int sensorMax1 = 0;           // maximum sensor value


void setup()
{  
  pinMode(LeftMotorForward, OUTPUT); 
  pinMode(LeftMotorReverse, OUTPUT);     
  pinMode(RightMotorForward, OUTPUT); 
  pinMode(RightMotorReverse, OUTPUT); 

 // turn on LED to signal the start of the calibration period:
  pinMode(13, OUTPUT);
  digitalWrite(13, HIGH);  
  
////// calibrate during the first five seconds  ////////////////
  while (millis() < 5000) {
    
sensorValue0 = analogRead(sensorPin0);
sensorValue1 = analogRead(sensorPin1);

    // record the maximum sensor value
    if (sensorValue0 > sensorMax0) {
      sensorMax0 = sensorValue0;
    }
    // record the minimum sensor value
    if (sensorValue0 < sensorMin0) {
      sensorMin0 = sensorValue0;
    }

    // record the maximum sensor value
    if (sensorValue1 > sensorMax1) {
      sensorMax1 = sensorValue1;
    }
    // record the minimum sensor value
    if (sensorValue1 < sensorMin1) {
      sensorMin1 = sensorValue1;
    }
    
  }//Ende while

digitalWrite(13, LOW);
}//Ende Setup


void loop()
{

//////////////////// A0 //////////////////////////////////////
// read the sensor:
  sensorValue0 = analogRead(sensorPin0);

  // apply the calibration to the sensor reading
  sensorValue0 = map(sensorValue0, sensorMin0, sensorMax0, 0, 255);

  // in case the sensor value is outside the range seen during calibration
  sensorValue0 = constrain(sensorValue0, 0, 255);
  
//////////////////////// A1 //////////////////////////////////
// read the sensor:
  sensorValue1 = analogRead(sensorPin1);

  // apply the calibration to the sensor reading
  sensorValue1 = map(sensorValue1, sensorMin1, sensorMax1, 0, 255);

  // in case the sensor value is outside the range seen during calibration
  sensorValue1 = constrain(sensorValue1, 0, 255); 
////////////////////////////////////////////////////////////////////

vor();

  if (sensorValue0 > 150) { //dunkel
       stoppen();
       rechts();
       stoppen();
    }


  if (sensorValue1 > 150) { //dunkel
       stoppen();
       links();
       stoppen();
    }


delay(50);  
}// Ende Loop

///////////// Subroutinen ////////////////////

 void stoppen(){
   digitalWrite(LeftMotorForward, LOW);   
   digitalWrite(LeftMotorReverse, LOW);   
   digitalWrite(RightMotorForward, LOW);  
   digitalWrite(RightMotorReverse, LOW);   
}
 
    
void rechts(){

   digitalWrite(RightMotorForward, HIGH);   
   digitalWrite(LeftMotorReverse, HIGH);   
   delay(150);           
 
   digitalWrite(RightMotorForward,LOW);   
   digitalWrite(LeftMotorReverse, LOW);   
}

void links(){

   digitalWrite(LeftMotorForward, HIGH);   
   digitalWrite(RightMotorReverse, HIGH);   
   delay(150);           
 
   digitalWrite(LeftMotorForward,LOW);   
   digitalWrite(RightMotorReverse, LOW);   
}

    
void vor(){
   digitalWrite(RightMotorForward, HIGH); 
   digitalWrite(LeftMotorForward, HIGH);  
}

void zurueck(){
   digitalWrite(RightMotorReverse, HIGH); 
   digitalWrite(LeftMotorReverse, HIGH);  
}