autom. trigger baro calib on boot

src/modules/sensors/vehicle_air_data/VehicleAirData.cpp

@@ -37,6 +37,7 @@
 #include <px4_platform_common/events.h>
 #include <lib/geo/geo.h>
 #include <lib/atmosphere/atmosphere.h>
+#include <uORB/topics/vehicle_command.h>
 
 namespace sensors
 {
@@ -293,6 +294,26 @@ void VehicleAirData::Run()
 				}
 			}
 		}
+
+		if (!_calibration_done) {
+			// allow all drivers to start up
+			_calibration_delay = _calibration_delay == 0 ? time_now_us : _calibration_delay;
+
+			if (time_now_us - _calibration_delay > 1_s) {
+				_calibration_done = true;
+				uORB::Publication<vehicle_command_s> _vehicle_command_sub{ORB_ID(vehicle_command)};
+				vehicle_command_s vcmd{};
+				vcmd.command = vehicle_command_s::VEHICLE_CMD_PREFLIGHT_CALIBRATION;
+				vcmd.param1 = 0;
+				vcmd.param2 = 0;
+				vcmd.param3 = 1;
+				vcmd.param4 = 0;
+				vcmd.param5 = 0;
+				vcmd.param6 = 0;
+				vcmd.param7 = 0;
+				_vehicle_command_sub.publish(vcmd);
+			}
+		}
 	}
 
 	if (!parameter_update) {

src/modules/sensors/vehicle_air_data/VehicleAirData.hpp

@@ -123,6 +123,9 @@ private:
 
 	float _air_temperature_celsius{20.f}; // initialize with typical 20degC ambient temperature
 
+	bool _calibration_done{false};
+	uint64_t _calibration_delay{0};
+
 	DEFINE_PARAMETERS(
 		(ParamFloat<px4::params::SENS_BARO_QNH>) _param_sens_baro_qnh,
 		(ParamFloat<px4::params::SENS_BARO_RATE>) _param_sens_baro_rate