calibration params: avoid using NaN as default

- NaN is not supported by JSON, and leads to parsing failure in QGC.
 - fixes https://github.com/PX4/PX4-Autopilot/issues/18095

src/lib/sensor_calibration/Accelerometer.cpp

@@ -210,7 +210,14 @@ void Accelerometer::ParametersUpdate()
 		}
 
 		// CAL_ACCx_TEMP
-		set_temperature(GetCalibrationParamFloat(SensorString(), "TEMP", _calibration_index));
+		float cal_temp = GetCalibrationParamFloat(SensorString(), "TEMP", _calibration_index);
+
+		if (cal_temp > TEMPERATURE_INVALID) {
+			set_temperature(cal_temp);
+
+		} else {
+			set_temperature(NAN);
+		}
 
 		// CAL_ACCx_OFF{X,Y,Z}
 		set_offset(GetCalibrationParamsVector3f(SensorString(), "OFF", _calibration_index));
@@ -263,7 +270,12 @@ bool Accelerometer::ParametersSave()
 			success &= SetCalibrationParam(SensorString(), "ROT", _calibration_index, -1);
 		}
 
-		success &= SetCalibrationParam(SensorString(), "TEMP", _calibration_index, _temperature);
+		if (PX4_ISFINITE(_temperature)) {
+			success &= SetCalibrationParam(SensorString(), "TEMP", _calibration_index, _temperature);
+
+		} else {
+			success &= SetCalibrationParam(SensorString(), "TEMP", _calibration_index, TEMPERATURE_INVALID);
+		}
 
 		return success;
 	}

src/lib/sensor_calibration/Accelerometer.hpp

@@ -92,6 +92,8 @@ public:
 	void SensorCorrectionsUpdate(bool force = false);
 
 private:
+	static constexpr float TEMPERATURE_INVALID = -1000.f;
+
 	uORB::Subscription _sensor_correction_sub{ORB_ID(sensor_correction)};
 
 	Rotation _rotation_enum{ROTATION_NONE};

src/lib/sensor_calibration/Gyroscope.cpp

@@ -195,7 +195,14 @@ void Gyroscope::ParametersUpdate()
 		}
 
 		// CAL_GYROx_TEMP
-		set_temperature(GetCalibrationParamFloat(SensorString(), "TEMP", _calibration_index));
+		float cal_temp = GetCalibrationParamFloat(SensorString(), "TEMP", _calibration_index);
+
+		if (cal_temp > TEMPERATURE_INVALID) {
+			set_temperature(cal_temp);
+
+		} else {
+			set_temperature(NAN);
+		}
 
 		// CAL_GYROx_OFF{X,Y,Z}
 		set_offset(GetCalibrationParamsVector3f(SensorString(), "OFF", _calibration_index));
@@ -243,7 +250,12 @@ bool Gyroscope::ParametersSave()
 			success &= SetCalibrationParam(SensorString(), "ROT", _calibration_index, -1);
 		}
 
-		success &= SetCalibrationParam(SensorString(), "TEMP", _calibration_index, _temperature);
+		if (PX4_ISFINITE(_temperature)) {
+			success &= SetCalibrationParam(SensorString(), "TEMP", _calibration_index, _temperature);
+
+		} else {
+			success &= SetCalibrationParam(SensorString(), "TEMP", _calibration_index, TEMPERATURE_INVALID);
+		}
 
 		return success;
 	}

src/lib/sensor_calibration/Gyroscope.hpp

@@ -96,6 +96,8 @@ public:
 	void SensorCorrectionsUpdate(bool force = false);
 
 private:
+	static constexpr float TEMPERATURE_INVALID = -1000.f;
+
 	uORB::Subscription _sensor_correction_sub{ORB_ID(sensor_correction)};
 
 	Rotation _rotation_enum{ROTATION_NONE};

src/lib/sensor_calibration/Magnetometer.cpp

@@ -195,7 +195,14 @@ void Magnetometer::ParametersUpdate()
 		}
 
 		// CAL_MAGx_TEMP
-		set_temperature(GetCalibrationParamFloat(SensorString(), "TEMP", _calibration_index));
+		float cal_temp = GetCalibrationParamFloat(SensorString(), "TEMP", _calibration_index);
+
+		if (cal_temp > TEMPERATURE_INVALID) {
+			set_temperature(cal_temp);
+
+		} else {
+			set_temperature(NAN);
+		}
 
 		// CAL_MAGx_OFF{X,Y,Z}
 		set_offset(GetCalibrationParamsVector3f(SensorString(), "OFF", _calibration_index));
@@ -263,7 +270,12 @@ bool Magnetometer::ParametersSave()
 			success &= SetCalibrationParam(SensorString(), "ROT", _calibration_index, -1);
 		}
 
-		success &= SetCalibrationParam(SensorString(), "TEMP", _calibration_index, _temperature);
+		if (PX4_ISFINITE(_temperature)) {
+			success &= SetCalibrationParam(SensorString(), "TEMP", _calibration_index, _temperature);
+
+		} else {
+			success &= SetCalibrationParam(SensorString(), "TEMP", _calibration_index, TEMPERATURE_INVALID);
+		}
 
 		return success;
 	}

src/lib/sensor_calibration/Magnetometer.hpp

@@ -100,6 +100,8 @@ public:
 	void UpdatePower(float power) { _power = power; }
 
 private:
+	static constexpr float TEMPERATURE_INVALID = -1000.f;
+
 	Rotation _rotation_enum{ROTATION_NONE};
 
 	matrix::Dcmf _rotation;

src/modules/sensors/sensor_params_acc0.c

@@ -172,8 +172,9 @@ PARAM_DEFINE_FLOAT(CAL_ACC0_ZSCALE, 1.0f);
  *
  * Temperature during last calibration.
  *
+ * @unit celcius
  * @category system
  * @group Sensor Calibration
  * @volatile
  */
-PARAM_DEFINE_FLOAT(CAL_ACC0_TEMP, NAN);
+PARAM_DEFINE_FLOAT(CAL_ACC0_TEMP, -1000.f);

src/modules/sensors/sensor_params_acc1.c

@@ -172,8 +172,9 @@ PARAM_DEFINE_FLOAT(CAL_ACC1_ZSCALE, 1.0f);
  *
  * Temperature during last calibration.
  *
+ * @unit celcius
  * @category system
  * @group Sensor Calibration
  * @volatile
  */
-PARAM_DEFINE_FLOAT(CAL_ACC1_TEMP, NAN);
+PARAM_DEFINE_FLOAT(CAL_ACC1_TEMP, -1000.f);

src/modules/sensors/sensor_params_acc2.c

@@ -172,8 +172,9 @@ PARAM_DEFINE_FLOAT(CAL_ACC2_ZSCALE, 1.0f);
  *
  * Temperature during last calibration.
  *
+ * @unit celcius
  * @category system
  * @group Sensor Calibration
  * @volatile
  */
-PARAM_DEFINE_FLOAT(CAL_ACC2_TEMP, NAN);
+PARAM_DEFINE_FLOAT(CAL_ACC2_TEMP, -1000.f);

src/modules/sensors/sensor_params_acc3.c

@@ -172,8 +172,9 @@ PARAM_DEFINE_FLOAT(CAL_ACC3_ZSCALE, 1.0f);
  *
  * Temperature during last calibration.
  *
+ * @unit celcius
  * @category system
  * @group Sensor Calibration
  * @volatile
  */
-PARAM_DEFINE_FLOAT(CAL_ACC3_TEMP, NAN);
+PARAM_DEFINE_FLOAT(CAL_ACC3_TEMP, -1000.f);

src/modules/sensors/sensor_params_gyro0.c

@@ -145,8 +145,9 @@ PARAM_DEFINE_FLOAT(CAL_GYRO0_ZOFF, 0.0f);
  *
  * Temperature during last calibration.
  *
+ * @unit celcius
  * @category system
  * @group Sensor Calibration
  * @volatile
  */
-PARAM_DEFINE_FLOAT(CAL_GYRO0_TEMP, NAN);
+PARAM_DEFINE_FLOAT(CAL_GYRO0_TEMP, -1000.f);

src/modules/sensors/sensor_params_gyro1.c

@@ -145,8 +145,9 @@ PARAM_DEFINE_FLOAT(CAL_GYRO1_ZOFF, 0.0f);
  *
  * Temperature during last calibration.
  *
+ * @unit celcius
  * @category system
  * @group Sensor Calibration
  * @volatile
  */
-PARAM_DEFINE_FLOAT(CAL_GYRO1_TEMP, NAN);
+PARAM_DEFINE_FLOAT(CAL_GYRO1_TEMP, -1000.f);

src/modules/sensors/sensor_params_gyro2.c

@@ -145,8 +145,9 @@ PARAM_DEFINE_FLOAT(CAL_GYRO2_ZOFF, 0.0f);
  *
  * Temperature during last calibration.
  *
+ * @unit celcius
  * @category system
  * @group Sensor Calibration
  * @volatile
  */
-PARAM_DEFINE_FLOAT(CAL_GYRO2_TEMP, NAN);
+PARAM_DEFINE_FLOAT(CAL_GYRO2_TEMP, -1000.f);

src/modules/sensors/sensor_params_gyro3.c

@@ -145,8 +145,9 @@ PARAM_DEFINE_FLOAT(CAL_GYRO3_ZOFF, 0.0f);
  *
  * Temperature during last calibration.
  *
+ * @unit celcius
  * @category system
  * @group Sensor Calibration
  * @volatile
  */
-PARAM_DEFINE_FLOAT(CAL_GYRO3_TEMP, NAN);
+PARAM_DEFINE_FLOAT(CAL_GYRO3_TEMP, -1000.f);

src/modules/sensors/sensor_params_mag0.c

@@ -241,8 +241,9 @@ PARAM_DEFINE_FLOAT(CAL_MAG0_ZCOMP, 0.0f);
  *
  * Temperature during last calibration.
  *
+ * @unit celcius
  * @category system
  * @group Sensor Calibration
  * @volatile
  */
-PARAM_DEFINE_FLOAT(CAL_MAG0_TEMP, NAN);
+PARAM_DEFINE_FLOAT(CAL_MAG0_TEMP, -1000.f);

src/modules/sensors/sensor_params_mag1.c

@@ -241,8 +241,9 @@ PARAM_DEFINE_FLOAT(CAL_MAG1_ZCOMP, 0.0f);
  *
  * Temperature during last calibration.
  *
+ * @unit celcius
  * @category system
  * @group Sensor Calibration
  * @volatile
  */
-PARAM_DEFINE_FLOAT(CAL_MAG1_TEMP, NAN);
+PARAM_DEFINE_FLOAT(CAL_MAG1_TEMP, -1000.f);

src/modules/sensors/sensor_params_mag2.c

@@ -241,8 +241,9 @@ PARAM_DEFINE_FLOAT(CAL_MAG2_ZCOMP, 0.0f);
  *
  * Temperature during last calibration.
  *
+ * @unit celcius
  * @category system
  * @group Sensor Calibration
  * @volatile
  */
-PARAM_DEFINE_FLOAT(CAL_MAG2_TEMP, NAN);
+PARAM_DEFINE_FLOAT(CAL_MAG2_TEMP, -1000.f);

src/modules/sensors/sensor_params_mag3.c

@@ -241,8 +241,9 @@ PARAM_DEFINE_FLOAT(CAL_MAG3_ZCOMP, 0.0f);
  *
  * Temperature during last calibration.
  *
+ * @unit celcius
  * @category system
  * @group Sensor Calibration
  * @volatile
  */
-PARAM_DEFINE_FLOAT(CAL_MAG3_TEMP, NAN);
+PARAM_DEFINE_FLOAT(CAL_MAG3_TEMP, -1000.f);