Robotbil med to hjul kode

// connect motor controller pins to Arduino digital pins
// motor one
int enA = 10;
int in1 = 9;
int in2 = 8;
// motor two
int enB = 5;
int in3 = 7;
int in4 = 6;

int distance = 0;
int MAX_DISTANCE = 300;

#define TRIG_PIN A0
#define ECHO_PIN A1
#include <NewPing.h>

NewPing sonar(TRIG_PIN, ECHO_PIN, MAX_DISTANCE);

void setup()
{
  // set all the motor control pins to outputs
  pinMode(enA, OUTPUT);
  pinMode(enB, OUTPUT);
  pinMode(in1, OUTPUT);
  pinMode(in2, OUTPUT);
  pinMode(in3, OUTPUT);
  pinMode(in4, OUTPUT);

  pinMode (TRIG_PIN, OUTPUT);
  pinMode (ECHO_PIN, INPUT);
  Serial.begin(9600);
  Serial.println("===== Selfguiding car =====");
}


void loop() // gentages
{

// turn on motor A and B:
digitalWrite(in1, LOW);  //motor A
  digitalWrite(in2, HIGH);
  digitalWrite(in3, LOW); //motor B
  digitalWrite(in4, HIGH);
  // set speed to 150 out of possible range 0~255
  analogWrite(enA, 150);
  // set speed to 150 out of possible range 0~255
  analogWrite(enB, 150);
  delay(200);

  distance = sonar.ping_cm(); // bestem afstanden og gem den i en variabel
  delay(200); // vent 0,2 sekunder
  Serial.print(distance);
  Serial.println(" cm");

if (distance < 15)
{
delay(100);
Serial.println("Turn");
digitalWrite(in1, HIGH);  //motor A
  digitalWrite(in2, LOW);
  digitalWrite(in3, LOW); //motor B
  digitalWrite(in4, HIGH);
  // set speed to 100 out of possible range 0~255
  analogWrite(enA, 100);
  // set speed to 100 out of possible range 0~255
  analogWrite(enB, 100);
  delay(200);
}

}