Last June we had help to install the driver: (https://github.com/ArduPilot/ardupilot/blob/master/libraries/AP_GPS/AP_GPS_NMEA.cpp)
to include the GPHDT sentence from our GPS Compass (Hemisphere V103). And it has worked fine apart from the fact that it is not being registered as a compass in ArduPilot.
Here it is in my back garden showing a YAW of 89.66, and the HDT message from the V103 says 89.79 and 89.96 so that is only minor differences. See the images here: https://drive.google.com/drive/folders/1JBcYNLrUGkxz3B5xXilkwony0HbonoFl?usp=sharing
So, how do we pass it on, so that it is shown on the HW ID list as a compass ? Is it maybe an amendment to the driver, that is needed ?