I was gave a following advice from Randy.
I think we should just make a new library similar to AP_FrSky_Telem then integrate it and see if people like it.. and then make it better let's start with something very simple.. like sending vehicle position and flight mode? .. and maybe accepting arm/disarm commands? what do you think?
Then I agreed this proposal .
I would like to sending a small amount of log data(i.e, drone identification number and vehicle position and flight mode), and accepting a small amount of command(i.e, arm and disarm...).
Maybe it would be an easier way to process commands by converting MQTT messages into MAVLink messages.