commander: report GNSS yaw fault to user

src/modules/commander/Commander.cpp

@@ -3786,6 +3786,8 @@ void Commander::estimator_check()
 	}
 
 	const bool mag_fault_prev = (_estimator_status_sub.get().control_mode_flags & (1 << estimator_status_s::CS_MAG_FAULT));
+	const bool gnss_heading_fault_prev = (_estimator_status_sub.get().control_mode_flags &
+					      (1 << estimator_status_s::CS_GPS_YAW_FAULT));
 
 	// use primary estimator_status
 	if (_estimator_selector_status_sub.updated()) {
@@ -3803,12 +3805,18 @@ void Commander::estimator_check()
 
 		// Check for a magnetomer fault and notify the user
 		const bool mag_fault = (estimator_status.control_mode_flags & (1 << estimator_status_s::CS_MAG_FAULT));
+		const bool gnss_heading_fault = (estimator_status.control_mode_flags & (1 << estimator_status_s::CS_GPS_YAW_FAULT));
 
 		if (!mag_fault_prev && mag_fault) {
 			mavlink_log_critical(&_mavlink_log_pub, "Stopping compass use! Check calibration on landing");
 			set_health_flags(subsystem_info_s::SUBSYSTEM_TYPE_MAG, true, true, false, _status);
 		}
 
+		if (!gnss_heading_fault_prev && gnss_heading_fault) {
+			mavlink_log_critical(&_mavlink_log_pub, "Stopping GNSS heading use! Check configuration on landing");
+			set_health_flags(subsystem_info_s::SUBSYSTEM_TYPE_GPS, true, true, false, _status);
+		}
+
 		/* Check estimator status for signs of bad yaw induced post takeoff navigation failure
 		 * for a short time interval after takeoff.
 		 * Most of the time, the drone can recover from a bad initial yaw using GPS-inertial

src/modules/ekf2/EKF/common.h

@@ -487,6 +487,7 @@ union filter_control_status_u {
 		uint32_t ev_vel      : 1; ///< 24 - true when local frame velocity data fusion from external vision measurements is intended
 		uint32_t synthetic_mag_z : 1; ///< 25 - true when we are using a synthesized measurement for the magnetometer Z component
 		uint32_t vehicle_at_rest : 1; ///< 26 - true when the vehicle is at rest
+		uint32_t gps_yaw_fault : 1; ///< 27 - true when the GNSS heading has been declared faulty and is no longer being used
 	} flags;
 	uint32_t value;
 };

src/modules/ekf2/EKF/control.cpp

@@ -751,7 +751,7 @@ void Ekf::controlGpsFusion()
 void Ekf::controlGpsYawFusion(bool gps_checks_passing, bool gps_checks_failing)
 {
 	if (!(_params.fusion_mode & MASK_USE_GPSYAW)
-	    || _is_gps_yaw_faulty) {
+	    || _control_status.flags.gps_yaw_fault) {
 
 		stopGpsYawFusion();
 		return;
@@ -793,7 +793,7 @@ void Ekf::controlGpsYawFusion(bool gps_checks_passing, bool gps_checks_failing)
 					} else if (starting_conditions_passing) {
 						// Data seems good, but previous reset did not fix the issue
 						// something else must be wrong, declare the sensor faulty and stop the fusion
-						_is_gps_yaw_faulty = true;
+						_control_status.flags.gps_yaw_fault = true;
 						stopGpsYawFusion();
 
 					} else {

src/modules/ekf2/EKF/ekf.h

@@ -536,7 +536,6 @@ private:
 	// height sensor status
 	bool _baro_hgt_faulty{false};		///< true if valid baro data is unavailable for use
 	bool _gps_hgt_intermittent{false};	///< true if gps height into the buffer is intermittent
-	bool _is_gps_yaw_faulty{false};		///< true if gps yaw data is rejected by the filter for too long
 
 	// imu fault status
 	uint64_t _time_bad_vert_accel{0};	///< last time a bad vertical accel was detected (uSec)

src/modules/ekf2/EKF/ekf_helper.cpp

@@ -1698,7 +1698,7 @@ bool Ekf::resetYawToEKFGSF()
 			_warning_events.flags.emergency_yaw_reset_mag_stopped = true;
 
 		} else if (_control_status.flags.gps_yaw) {
-			_is_gps_yaw_faulty = true;
+			_control_status.flags.gps_yaw_fault = true;
 			_warning_events.flags.emergency_yaw_reset_gps_yaw_stopped = true;
 
 		} else if (_control_status.flags.ev_yaw) {

src/modules/ekf2/EKF2.cpp

@@ -641,6 +641,7 @@ void EKF2::PublishEventFlags(const hrt_abstime &timestamp)
 		event_flags.stopping_mag_use                    = _ekf.warning_event_flags().stopping_mag_use;
 		event_flags.vision_data_stopped                 = _ekf.warning_event_flags().vision_data_stopped;
 		event_flags.emergency_yaw_reset_mag_stopped     = _ekf.warning_event_flags().emergency_yaw_reset_mag_stopped;
+		event_flags.emergency_yaw_reset_gps_yaw_stopped = _ekf.warning_event_flags().emergency_yaw_reset_gps_yaw_stopped;
 
 		event_flags.timestamp = _replay_mode ? timestamp : hrt_absolute_time();
 		_estimator_event_flags_pub.publish(event_flags);
@@ -1172,6 +1173,7 @@ void EKF2::PublishStatusFlags(const hrt_abstime &timestamp)
 		status_flags.cs_ev_vel                = _ekf.control_status_flags().ev_vel;
 		status_flags.cs_synthetic_mag_z       = _ekf.control_status_flags().synthetic_mag_z;
 		status_flags.cs_vehicle_at_rest       = _ekf.control_status_flags().vehicle_at_rest;
+		status_flags.cs_gps_yaw_fault         = _ekf.control_status_flags().gps_yaw_fault;
 
 		status_flags.fault_status_changes     = _filter_fault_status_changes;
 		status_flags.fs_bad_mag_x             = _ekf.fault_status_flags().bad_mag_x;