AP_ExternalAHRS: Added filter updates for advanced navigation devices

When running EAHRS update it will now check for flight mode and gnss enable and request the appropriate changes in the device filter.

libraries/AP_ExternalAHRS/AP_ExternalAHRS_AdvancedNavigation.cpp

@@ -236,6 +236,19 @@ bool AP_ExternalAHRS_AdvancedNavigation::request_data(void)
         }
     }
 
+    // check for updates to environment that require INS filter updates
+    if (_fly_forward != in_fly_forward() || _gnss_disable != gnss_is_disabled()){
+        _fly_forward = in_fly_forward();
+        _gnss_disable = gnss_is_disabled();
+
+        // Select AdNav vehicle for current flight mode. 
+        vehicle_type_e vehicle_type = vehicle_type_3d_aircraft;
+        if (_fly_forward == true) {
+            vehicle_type = vehicle_type_fixed_wing_plane;
+        }
+
+        set_filter_options(!_gnss_disable, vehicle_type);
+    }
     return true;
 }
 

libraries/AP_ExternalAHRS/AP_ExternalAHRS_AdvancedNavigation.h

@@ -478,6 +478,9 @@ class AP_ExternalAHRS_AdvancedNavigation: public AP_ExternalAHRS_backend
     uint32_t _last_raw_gnss_pkt_ms;
     uint32_t _device_id;
     uint32_t _hardware_rev;
+
+    bool _gnss_disable;
+    bool _fly_forward;
 
     void update_thread();
     bool get_packets(void);