car_if_else

void loop()
{
  getDistance();
  if (distance > 20)
    goForward();
  else
    goBackward();
}

void goForward()
{
  Serial.println("Going forward");
  analogWrite(enA, runSpeed*3/4);
  analogWrite(enB, runSpeed*3/4);
  digitalWrite(leftBack,LOW);
  digitalWrite(leftFwd,HIGH);
  digitalWrite(rightBack,LOW);
  digitalWrite(rightFwd,HIGH);
}

void goBackward()
{
  Serial.println("Going backward");
  analogWrite(enA, runSpeed*1/2);
  analogWrite(enB, runSpeed*1/2);
  digitalWrite(leftBack,HIGH);
  digitalWrite(leftFwd,LOW);
  digitalWrite(rightBack,HIGH);
  digitalWrite(rightFwd,LOW);
}

int getDistance()
{
  //  Getting the distance from the sensor
  long duration, distance;
  digitalWrite(trig,HIGH);
  delayMicroseconds(1000);
  digitalWrite(trig, LOW);
  duration=pulseIn(echo, HIGH);
  distance =(duration/2)/29.1;
  Serial.print(distance);
  Serial.println(" cm");
  delay(10);
  return distance;
}