SITL: set a reasonable number of satellites in simulated uBlox

libraries/Desktop/support/sitl_gps.cpp

@@ -131,9 +131,29 @@ void sitl_update_gps(double latitude, double longitude, float altitude,
 		uint32_t	speed_accuracy;
 		uint32_t	heading_accuracy;
 	} velned;
+	struct ubx_nav_solution {
+		uint32_t time;
+		int32_t time_nsec;
+		int16_t week;
+		uint8_t fix_type;
+		uint8_t fix_status;
+		int32_t ecef_x;
+		int32_t ecef_y;
+		int32_t ecef_z;
+		uint32_t position_accuracy_3d;
+		int32_t ecef_x_velocity;
+		int32_t ecef_y_velocity;
+		int32_t ecef_z_velocity;
+		uint32_t speed_accuracy;
+		uint16_t position_DOP;
+		uint8_t res;
+		uint8_t satellites;
+		uint32_t res2;
+	} sol;
         const uint8_t MSG_POSLLH = 0x2;
 	const uint8_t MSG_STATUS = 0x3;
 	const uint8_t MSG_VELNED = 0x12;
+        const uint8_t MSG_SOL = 0x6;
 	struct gps_data d;
 
 	// 5Hz, to match the real UBlox config in APM
@@ -195,6 +215,11 @@ void sitl_update_gps(double latitude, double longitude, float altitude,
 	velned.speed_accuracy = 2;
 	velned.heading_accuracy = 4;
 
+	memset(&sol, 0, sizeof(sol));
+	sol.fix_type = d.have_lock?3:0;
+	sol.fix_status = 221;
+	sol.satellites = d.have_lock?10:3;
+
 	if (gps_state.gps_fd == 0) {
 		return;
 	}
@@ -202,4 +227,5 @@ void sitl_update_gps(double latitude, double longitude, float altitude,
 	gps_send(MSG_POSLLH, (uint8_t*)&pos, sizeof(pos));
 	gps_send(MSG_STATUS, (uint8_t*)&status, sizeof(status));
 	gps_send(MSG_VELNED, (uint8_t*)&velned, sizeof(velned));
+	gps_send(MSG_SOL,    (uint8_t*)&sol, sizeof(sol));
 }