   inputString.reserve(200);
   
   pinMode(LED_PIN, OUTPUT);
+  
+  // Left motor power wiring is reversed.
+  motors.flipLeftMotor(true);
+  
+  // Initial speed is zero
   motors.setLeftSpeed(0);
   motors.setRightSpeed(0);
 }

      break;
      
      case 'c':
      // Both
      vel = Serial.parseInt();
      vel = constrain(vel, -400, 400);
      vel2 = Serial.parseInt();
      vel2 = constrain(vel2, -400, 400);
      Serial.print("Both ");
      Serial.print(vel);
      Serial.print(" ");
      Serial.println(vel2);
      drive(vel,vel2,250);
      break;
      
      case 'd':

 response.  Multiple bytes of data may be available.
 */
void serialEvent() {
  int vel, vel2, dt;
  while (Serial.available()) {
    // Get state character from buffer
    char c = (char)Serial.read();
