remove temp field from airspeed.msg, adjust temp selection

msg/Airspeed.msg

@@ -5,6 +5,4 @@ float32 indicated_airspeed_m_s   # indicated airspeed in m/s
 
 float32 true_airspeed_m_s        # true filtered airspeed in m/s
 
-float32 air_temperature_celsius  # air temperature in degrees Celsius, -1000 if unknown
-
 float32 confidence               # confidence value from 0 to 1 for this sensor

msg/VehicleAirData.msg

@@ -6,10 +6,9 @@ uint64 timestamp_sample     # the timestamp of the raw data (microseconds)
 uint32 baro_device_id       # unique device ID for the selected barometer
 
 float32 baro_alt_meter			# Altitude above MSL calculated from temperature compensated baro sensor data using an ISA corrected for sea level pressure SENS_BARO_QNH.
-float32 baro_temp_celcius		# Temperature in degrees Celsius
 float32 baro_pressure_pa		# Absolute pressure in Pascals
+float32 ambient_temperature		# Abient temperature in degrees Celsius
 
 float32 rho				# air density
-float32 eas2tas         # equivalent airspeed to true airspeed conversion factor
 
 uint8 calibration_count     # Calibration changed counter. Monotonically increases whenever calibration changes.

src/drivers/telemetry/hott/messages.cpp

@@ -150,7 +150,7 @@ build_eam_response(uint8_t *buffer, size_t *size)
 	msg.eam_sensor_id = EAM_SENSOR_ID;
 	msg.sensor_text_id = EAM_SENSOR_TEXT_ID;
 
-	msg.temperature1 = (uint8_t)(airdata.baro_temp_celcius + 20);
+	msg.temperature1 = (uint8_t)(airdata.ambient_temperature + 20);
 	msg.temperature2 = msg.temperature1 - BOARD_TEMP_OFFSET_DEG;
 
 	msg.main_voltage_L = (uint8_t)(battery.voltage_v * 10);

src/modules/airspeed_selector/airspeed_selector_main.cpp

@@ -388,7 +388,7 @@ AirspeedModule::Run()
 				input_data.airspeed_indicated_raw = airspeed_raw.indicated_airspeed_m_s;
 				input_data.airspeed_true_raw = airspeed_raw.true_airspeed_m_s;
 				input_data.airspeed_timestamp = airspeed_raw.timestamp;
-				input_data.air_temperature_celsius = airspeed_raw.air_temperature_celsius;
+				input_data.air_temperature_celsius = _vehicle_air_data.ambient_temperature;
 
 				if (_in_takeoff_situation) {
 					// set flag to false if either speed is above stall speed,

src/modules/mavlink/mavlink_receiver.cpp

@@ -2669,7 +2669,6 @@ MavlinkReceiver::handle_message_hil_state_quaternion(mavlink_message_t *msg)
 		airspeed.timestamp_sample = timestamp_sample;
 		airspeed.indicated_airspeed_m_s = hil_state.ind_airspeed * 1e-2f;
 		airspeed.true_airspeed_m_s = hil_state.true_airspeed * 1e-2f;
-		airspeed.air_temperature_celsius = 15.f;
 		airspeed.timestamp = hrt_absolute_time();
 		_airspeed_pub.publish(airspeed);
 	}

src/modules/mavlink/streams/HIGHRES_IMU.hpp

@@ -193,7 +193,7 @@ class MavlinkStreamHighresIMU : public MavlinkStream
 			msg.abs_pressure = air_data.baro_pressure_pa;
 			msg.diff_pressure = differential_pressure.differential_pressure_pa;
 			msg.pressure_alt = air_data.baro_alt_meter;
-			msg.temperature = air_data.baro_temp_celcius;
+			msg.temperature = air_data.ambient_temperature;
 			msg.fields_updated = fields_updated;
 
 			mavlink_msg_highres_imu_send_struct(_mavlink->get_channel(), &msg);

src/modules/mavlink/streams/HIGH_LATENCY2.hpp

@@ -57,6 +57,7 @@
 #include <uORB/topics/vehicle_status.h>
 #include <uORB/topics/failsafe_flags.h>
 #include <uORB/topics/health_report.h>
+#include <uORB/topics/vehicle_air_data.h>
 
 #include <px4_platform_common/events.h>
 
@@ -521,6 +522,7 @@ class MavlinkStreamHighLatency2 : public MavlinkStream
 		update_gps();
 		update_vehicle_status();
 		update_wind();
+		update_vehicle_air_data();
 	}
 
 	void update_airspeed()
@@ -529,7 +531,6 @@ class MavlinkStreamHighLatency2 : public MavlinkStream
 
 		if (_airspeed_sub.update(&airspeed)) {
 			_airspeed.add_value(airspeed.indicated_airspeed_m_s, _update_rate_filtered);
-			_temperature.add_value(airspeed.air_temperature_celsius, _update_rate_filtered);
 		}
 	}
 
@@ -610,6 +611,15 @@ class MavlinkStreamHighLatency2 : public MavlinkStream
 		}
 	}
 
+	void update_vehicle_air_data()
+	{
+		vehicle_air_data_s air_data;
+
+		if (_vehicle_air_data_sub.update(&air_data)) {
+			_temperature.add_value(air_data.ambient_temperature, _update_rate_filtered);
+		}
+	}
+
 	void set_default_values(mavlink_high_latency2_t &msg) const
 	{
 		msg.airspeed = 0;
@@ -659,6 +669,7 @@ class MavlinkStreamHighLatency2 : public MavlinkStream
 	uORB::Subscription _tecs_status_sub{ORB_ID(tecs_status)};
 	uORB::Subscription _wind_sub{ORB_ID(wind)};
 	uORB::Subscription _health_report_sub{ORB_ID(health_report)};
+	uORB::Subscription _vehicle_air_data_sub{ORB_ID(vehicle_air_data)};
 
 	SimpleAnalyzer _airspeed;
 	SimpleAnalyzer _airspeed_sp;

src/modules/sensors/sensors.cpp

@@ -286,14 +286,11 @@ void Sensors::diff_pres_poll()
 
 			air_temperature_celsius = diff_pres.temperature;
 
-		} else {
+		} else if ((air_data.timestamp != 0) && PX4_ISFINITE(air_data.ambient_temperature)
+			   && (air_data.ambient_temperature >= -40.f) && (air_data.ambient_temperature <= 125.f)) {
 			// differential pressure temperature invalid, check barometer
-			if ((air_data.timestamp != 0) && PX4_ISFINITE(air_data.baro_temp_celcius)
-			    && (air_data.baro_temp_celcius >= -40.f) && (air_data.baro_temp_celcius <= 125.f)) {
-
-				// TODO: review PCB_TEMP_ESTIMATE_DEG, ignore for external baro
-				air_temperature_celsius = air_data.baro_temp_celcius - PCB_TEMP_ESTIMATE_DEG;
-			}
+			// TODO: review PCB_TEMP_ESTIMATE_DEG, ignore for external baro
+			air_temperature_celsius = air_data.ambient_temperature - PCB_TEMP_ESTIMATE_DEG;
 		}
 
 		// push raw data into validator
@@ -354,7 +351,6 @@ void Sensors::diff_pres_poll()
 				airspeed.timestamp_sample = timestamp_sample;
 				airspeed.indicated_airspeed_m_s = indicated_airspeed_m_s;
 				airspeed.true_airspeed_m_s = true_airspeed_m_s;
-				airspeed.air_temperature_celsius = temperature;
 				airspeed.confidence = _airspeed_validator.confidence(hrt_absolute_time());
 				airspeed.timestamp = hrt_absolute_time();
 				_airspeed_pub.publish(airspeed);

src/modules/sensors/vehicle_air_data/VehicleAirData.cpp

@@ -77,20 +77,23 @@ void VehicleAirData::Stop()
 	}
 }
 
-void VehicleAirData::AirTemperatureUpdate()
+void VehicleAirData::AirTemperatureUpdate(float &temperature)
 {
+	// use the temperature from the differential pressure sensor if available
+	// otherwise use the temperature from the selected barometer
 	differential_pressure_s differential_pressure;
-
-	static constexpr float temperature_min_celsius = -20.f;
-	static constexpr float temperature_max_celsius = 35.f;
+	static constexpr float temperature_min_celsius = -40.f;
+	static constexpr float temperature_max_celsius = 125.f;
 
 	// update air temperature if data from differential pressure sensor is finite and not exactly 0
 	// limit the range to max 35°C to limt the error due to heated up airspeed sensors prior flight
-	if (_differential_pressure_sub.update(&differential_pressure) && PX4_ISFINITE(differential_pressure.temperature)
-	    && fabsf(differential_pressure.temperature) > FLT_EPSILON) {
+	if (_differential_pressure_sub.copy(&differential_pressure)
+	    && hrt_absolute_time() - differential_pressure.timestamp_sample < 1_s
+	    && PX4_ISFINITE(differential_pressure.temperature)
+	) {
 
-		_air_temperature_celsius = math::constrain(differential_pressure.temperature, temperature_min_celsius,
-					   temperature_max_celsius);
+		temperature = math::constrain(differential_pressure.temperature, temperature_min_celsius,
+					      temperature_max_celsius);
 	}
 }
 
@@ -139,8 +142,6 @@ void VehicleAirData::Run()
 
 	const bool parameter_update = ParametersUpdate();
 
-	AirTemperatureUpdate();
-
 	bool updated[MAX_SENSOR_COUNT] {};
 
 	for (int uorb_index = 0; uorb_index < MAX_SENSOR_COUNT; uorb_index++) {
@@ -260,7 +261,8 @@ void VehicleAirData::Run()
 
 					if (publish) {
 						const float pressure_pa = _data_sum[instance] / _data_sum_count[instance];
-						const float temperature = _temperature_sum[instance] / _data_sum_count[instance];
+						float temperature = _temperature_sum[instance] / _data_sum_count[instance];
+						AirTemperatureUpdate(temperature);
 
 						const float pressure_sealevel_pa = _param_sens_baro_qnh.get() * 100.f;
 						const float altitude = getAltitudeFromPressure(pressure_pa, pressure_sealevel_pa);
@@ -273,10 +275,9 @@ void VehicleAirData::Run()
 						out.timestamp_sample = timestamp_sample;
 						out.baro_device_id = _calibration[instance].device_id();
 						out.baro_alt_meter = altitude;
-						out.baro_temp_celcius = temperature;
+						out.ambient_temperature = temperature;
 						out.baro_pressure_pa = pressure_pa;
 						out.rho = air_density;
-						out.eas2tas = sqrtf(kAirDensitySeaLevelStandardAtmos / math::max(air_density, FLT_EPSILON));
 						out.calibration_count = _calibration[instance].calibration_count();
 						out.timestamp = hrt_absolute_time();
 

src/modules/sensors/vehicle_air_data/VehicleAirData.hpp

@@ -74,7 +74,7 @@ class VehicleAirData : public ModuleParams, public px4::ScheduledWorkItem
 private:
 	void Run() override;
 
-	void AirTemperatureUpdate();
+	void AirTemperatureUpdate(float &temperature);
 	void CheckFailover(const hrt_abstime &time_now_us);
 	bool ParametersUpdate(bool force = false);
 	void UpdateStatus();
@@ -121,8 +121,6 @@ class VehicleAirData : public ModuleParams, public px4::ScheduledWorkItem
 
 	int8_t _selected_sensor_sub_index{-1};
 
-	float _air_temperature_celsius{20.f}; // initialize with typical 20degC ambient temperature
-
 	DEFINE_PARAMETERS(
 		(ParamFloat<px4::params::SENS_BARO_QNH>) _param_sens_baro_qnh,
 		(ParamFloat<px4::params::SENS_BARO_RATE>) _param_sens_baro_rate

src/modules/simulation/simulator_sih/sih.cpp

@@ -556,7 +556,6 @@ void Sih::send_airspeed(const hrt_abstime &time_now_us)
 	// regardless of vehicle type, body frame, etc this holds as long as wind=0
 	airspeed.true_airspeed_m_s = fmaxf(0.1f, _v_E.norm() + generate_wgn() * 0.2f);
 	airspeed.indicated_airspeed_m_s = airspeed.true_airspeed_m_s * sqrtf(_wing_l.get_rho() / RHO);
-	airspeed.air_temperature_celsius = NAN;
 	airspeed.confidence = 0.7f;
 	airspeed.timestamp = hrt_absolute_time();
 	_airspeed_pub.publish(airspeed);