Control mode where the height is send as an absolute setpoint (intended
        to be the distance to the surface under the Crazflie).

        Roll, pitch, yawrate are defined as degrees, degrees, degrees/s

def send_zdistance_setpoint(self, roll, pitch, yawrate, zdistance):
        """
        Control mode where the height is send as an absolute setpoint (intended
        to be the distance to the surface under the Crazflie).

        Roll, pitch, yawrate are defined as degrees, degrees, degrees/s
        """
        pk = CRTPPacket()
        pk.port = CRTPPort.COMMANDER_GENERIC
        pk.data = struct.pack('<Bffff', TYPE_ZDISTANCE,
                              roll, pitch, yawrate, zdistance)
        self._cf.send_packet(pk)