./steer.py: to start the robucar in full RS232 mode and driving forward with a steering angle on both front and back wheel
./stop.py: to set the speed of the robucar to zero with no steering.
./warning.py: to start the robucar in full RS232 + ultrasonic protection, set the sound type for the warnings(section 8.7), enable the warning(reduce the speed by 2 when detecting warnings, see section 8.4), drive forward and read the status (see section 8.6)