handle an incoming mavlink packet

def mavlink_packet(self, m):
        """handle an incoming mavlink packet"""
        mtype = m.get_type()
        if mtype == 'GPS_RAW':
            (self.lat, self.lon) = (m.lat, m.lon)
        elif mtype == 'GPS_RAW_INT':
            (self.lat, self.lon) = (m.lat / 1.0e7, m.lon / 1.0e7)
        elif mtype == "VFR_HUD":
            self.heading = m.heading
            self.alt = m.alt
            self.airspeed = m.airspeed
            self.groundspeed = m.groundspeed