Marvelmind GPS NMEA $GPHDT or u-blox yaw


I am trying to utilize the heading output from a Marvelmind system for indoor navigation and disable compasses. I have tried the NMEA and u-blox license from Marvelmind. Location works for either license. Heading does not seem to work for the u-blox license at all, I don’t see the simulated compass coming in on Serial 3/GPS1. Heading partially seems to work with the NMEA license. On powerup, the heading eventually snaps to some value other than north (so not dead reckoning), and the EKF status shows the compass bar moving, and if I disable the heading output in Marvelminds dashboard the EKF Status for Compass goes to zero. Also, in MAVLink Inspector I see the gps yaw changing. If I take the two paired beacons off the rover and move them in yaw, nothing moves in MP, the EKF status for Compass moves and goes red.

Below are my parameters for Rover (goal is to move this to copter) for NMEA $GPHDT, using the GPS2 (Serial 4) port.

Also, I’ve included links to all applicable posts and commits I could find.

Any help is much appreciated! Thank you.

Rover_MarvelMind_NMEA_GPS2.param (14.7 KB)