@Jaeyoung-Lim Hi and thank you for reply.
I've already seen your 404warehouse blog, etc. I really enjoy it.
I tried your example code to offboard control my drone, but have problem:
First of all, my drone flows away from launching position. I don't need exact (0,0,0),
but I think it could be the reason to flow, so...
And when launching, it constantly turns in yaw axis. literally.
Finally, though my control command is go to (0,0,1.5), my drone doesn't fly to 1.5m high. It takes off nearly half of 1.5m.
All my mavros command is setting position setpoint to (0,0,0).
Again, thanks for your reply.