   motor3.setSpeed(motorSpeed);
   motor4.setSpeed(motorSpeed);
 }
+
+String getDistance(int argument) {
+  unsigned int uS = sonar.ping();
+  return String("Ping: ") + String(uS / US_ROUNDTRIP_CM) + String("cm");
+}

AF_DCMotor motor2(2);
AF_DCMotor motor3(3);
AF_DCMotor motor4(4);

int motorSpeed = 100;
bool isMovingForward = false;

  
  if(command == "battery") {
    result = checkBatteryStatus(argument);
  } else if(command == "distance") {
    result = getDistance(argument);
  } else if(command == "forward") {
    result = forward(argument);
  } else if(command == "backward") {
