Hi,
I want to send a custom uOrb message through mavlink.
I follow the guide: http://dev.px4.io/custom-mavlink-message.html.
The class that I added to mavlink_messages.cpp is this one:
class MavlinkStreamCaTrajectory : public MavlinkStream
{
public:
const char *get_name() const
{
return MavlinkStreamCaTrajectory::get_name_static();
}
static const char *get_name_static()
{
return "CA_TRAJECTORY";
}
static uint8_t get_id_static()
{
return MAVLINK_MSG_ID_CA_TRAJECTORY;
}
uint8_t get_id()
{
return get_id_static();
}
static MavlinkStream *new_instance(Mavlink *mavlink)
{
return new MavlinkStreamCaTrajectory(mavlink);
}
unsigned get_size()
{
return MAVLINK_MSG_ID_CA_TRAJECTORY_LEN + MAVLINK_NUM_NON_PAYLOAD_BYTES;
}
private:
MavlinkOrbSubscription *_sub;
uint64_t _ca_traj_time;
/* do not allow top copying this class */
MavlinkStreamCaTrajectory(MavlinkStreamCaTrajectory &);
MavlinkStreamCaTrajectory& operator = (const MavlinkStreamCaTrajectory &);
protected:
explicit MavlinkStreamCaTrajectory(Mavlink *mavlink) : MavlinkStream(mavlink),
_sub(_mavlink->add_orb_subscription(ORB_ID(ca_trajectory))), // make sure you enter the name of your uorb topic here
_ca_traj_time(0)
{}
void send(const hrt_abstime t)
{
struct ca_traj_struct_s _ca_trajectory; //make sure ca_traj_struct_s is the definition of your uorb topic
if (_sub->update(&_ca_traj_time, &_ca_trajectory)) {
mavlink_ca_trajectory_t _msg_ca_trajectory; //make sure mavlink_ca_trajectory_t is the definition of your custom mavlink message
_msg_ca_trajectory.timestamp = _ca_trajectory.timestamp;
_msg_ca_trajectory.time_start_usec = _ca_trajectory.time_start_usec;
_msg_ca_trajectory.time_stop_usec = _ca_trajectory.time_stop_usec;
_msg_ca_trajectory.coefficients =_ca_trajectory.coefficients;
_msg_ca_trajectory.seq_id = _ca_trajectory.seq_id;
mavlink_msg_ca_trajectory_send_struct(_mavlink->get_channel(), &_msg_ca_trajectory);
}
}
};
I appended the stream class
StreamListItem *streams_list[] = {
...
new StreamListItem(&MavlinkStreamCaTrajectory::new_instance, &MavlinkStreamCaTrajectory::get_name_static,&MavlinkStreamCaTrajectory::get_id_static),nullptr
};
Differences respect to the guide:
- Since the constructor of class
StreamListItemrequires theidi added the methodget_name_statictoMavlinkStreamCaTrajectoryclass. - In the
sendmethod of classMavlinkStreamCaTrajectoryI changed the method
_mavlink->send_message(MAVLINK_MSG_ID_CA_TRAJECTORY, &_msg_ca_trajectory);
with:
mavlink_msg_ca_trajectory_send_struct(_mavlink->get_channel(), &_msg_ca_trajectory);
because I had a compile error.
Now I am able to compile the code but the function send is never used even if I send ca_trajectory uOrb message and I don’t recive any ca_trajectory mavlink message.
I think that something is missed but I don’t no what.
