add iris_dual_gps config and the possibility of testing GPS blending through simulation

ROMFS/px4fmu_common/init.d-posix/1019_iris_dual_gps

@@ -0,0 +1,14 @@
+#!/bin/sh
+#
+# @name 3DR Iris Quadrotor SITL (Dual GPS)
+#
+# @type Quadrotor Wide
+#
+
+sh /etc/init.d-posix/10016_iris
+
+if [ $AUTOCNF = yes ]
+then
+	# EKF2: Multi GPS blending
+	param set EKF2_GPS_MASK 7 # Uses speed, hpos and vpos accuracy
+fi

platforms/posix/cmake/sitl_target.cmake

@@ -76,7 +76,7 @@ ExternalProject_Add(flightgear_bridge
 set(viewers none jmavsim gazebo)
 set(debuggers none ide gdb lldb ddd valgrind callgrind)
 set(models none shell
-	if750a iris iris_opt_flow iris_opt_flow_mockup iris_vision iris_rplidar iris_irlock iris_obs_avoid iris_rtps px4vision solo typhoon_h480
+	if750a iris iris_dual_gps iris_opt_flow iris_opt_flow_mockup iris_vision iris_rplidar iris_irlock iris_obs_avoid iris_rtps px4vision solo typhoon_h480
 	plane plane_cam plane_catapult plane_lidar
 	standard_vtol tailsitter tiltrotor
 	rover r1_rover boat

src/modules/simulator/simulator.h

@@ -248,7 +248,8 @@ private:
 	uORB::Publication<input_rc_s>			_input_rc_pub{ORB_ID(input_rc)};
 
 	// HIL GPS
-	uORB::Publication<vehicle_gps_position_s>	_vehicle_gps_position_pub{ORB_ID(vehicle_gps_position)};
+	uORB::PublicationMulti<vehicle_gps_position_s>	*_vehicle_gps_position_pubs[ORB_MULTI_MAX_INSTANCES] {};
+	uint8_t _gps_ids[ORB_MULTI_MAX_INSTANCES] {};
 	std::default_random_engine _gen{};
 
 	// uORB subscription handlers

src/modules/simulator/simulator_mavlink.cpp

@@ -309,7 +309,21 @@ void Simulator::handle_message_hil_gps(const mavlink_message_t *msg)
 		gps.satellites_used = hil_gps.satellites_visible;
 		gps.s_variance_m_s = 0.25f;
 
-		_vehicle_gps_position_pub.publish(gps);
+		// New publishers will be created based on the HIL_GPS ID's being different or not
+		for (size_t i = 0; i < sizeof(_gps_ids) / sizeof(_gps_ids[0]); i++) {
+			if (_vehicle_gps_position_pubs[i] && _gps_ids[i] == hil_gps.id) {
+				_vehicle_gps_position_pubs[i]->publish(gps);
+				break;
+
+			}
+
+			if (_vehicle_gps_position_pubs[i] == nullptr) {
+				_vehicle_gps_position_pubs[i] = new uORB::PublicationMulti<vehicle_gps_position_s> {ORB_ID(vehicle_gps_position)};
+				_gps_ids[i] = hil_gps.id;
+				_vehicle_gps_position_pubs[i]->publish(gps);
+				break;
+			}
+		}
 	}
 }