I have several devices with NMEA 0183 support, one of them is a compass\heave sensor.
I think it would be good to add “nmea input” support to “SERIAL*_PROTOCOL”. Moreover, the “nmea output” is already there. This would allow a group of devices connected by the nmea multiplexer and Pixhawk to exchange data on one port.
I am also currently making a weather vane transmitting nmea data.
My compass