Barometer: fixed airstart for APM

we need to re-load the ground pressure and temperature from eeprom on
and airstart

ArduPlane/GCS_Mavlink.pde

@@ -465,7 +465,7 @@ static void NOINLINE send_raw_imu2(mavlink_channel_t chan)
         chan,
         micros(),
         pressure/100.0,
-        (pressure - g.ground_pressure)/100.0,
+        (pressure - barometer.get_ground_pressure())/100.0,
         barometer.get_temperature());
 }
 

ArduPlane/Parameters.h

@@ -91,9 +91,12 @@ public:
         k_param_imu = 130,  // sensor calibration
         k_param_altitude_mix,
         k_param_airspeed_ratio,
-        k_param_ground_temperature,
-        k_param_ground_pressure,
-		k_param_compass_enabled,
+
+        // ground_pressure and ground_temperature removed
+        // do not re-use 133 and 134 unless format_version
+        // is changed
+
+		k_param_compass_enabled = 135,
 		k_param_compass,
 		k_param_battery_monitoring,
 		k_param_volt_div_ratio,
@@ -105,6 +108,7 @@ public:
 		k_param_airspeed_enabled,
         k_param_ahrs,  // AHRS group
 		k_param_airspeed_use,
+        k_param_barometer,   // barometer ground calibration
 
         //
         // 150: Navigation parameters
@@ -333,8 +337,6 @@ public:
     AP_Int16    min_gndspeed;
     AP_Int16    pitch_trim;
     AP_Int16    RTL_altitude;
-    AP_Int16    ground_temperature;
-    AP_Int32    ground_pressure;
     AP_Int8		compass_enabled;
     AP_Int16    angle_of_attack;
     AP_Int8		battery_monitoring;	// 0=disabled, 3=voltage only, 4=voltage and current
@@ -454,8 +456,6 @@ public:
         pitch_trim              (0),
         RTL_altitude            (ALT_HOLD_HOME_CM),
         FBWB_min_altitude       (ALT_HOLD_FBW_CM),
-        ground_temperature      (0),
-        ground_pressure         (0),
         compass_enabled			(MAGNETOMETER),
         flap_1_percent			(FLAP_1_PERCENT),
         flap_1_speed			(FLAP_1_SPEED),

ArduPlane/Parameters.pde

@@ -234,8 +234,6 @@ static const AP_Param::Info var_info[] PROGMEM = {
 	GSCALAR(pitch_trim,             "TRIM_PITCH_CD"),
 	GSCALAR(RTL_altitude,           "ALT_HOLD_RTL"),
 	GSCALAR(FBWB_min_altitude,      "ALT_HOLD_FBWCM"),
-	GSCALAR(ground_temperature,     "GND_TEMP"),
-	GSCALAR(ground_pressure,        "GND_ABS_PRESS"),
 
     // @Param: MAG_ENABLE
 	// @DisplayName: Enable Compass
@@ -277,6 +275,10 @@ static const AP_Param::Info var_info[] PROGMEM = {
 	// @User: Advanced
 	GSCALAR(airspeed_use,       	"ARSPD_USE"),
 
+	// barometer ground calibration. The GND_ prefix is chosen for
+	// compatibility with previous releases of ArduPlane
+	GOBJECT(barometer, "GND_", AP_Baro),
+
 #if CAMERA == ENABLED
 	// @Group: CAM_
 	// @Path: ../libraries/AP_Camera/AP_Camera.cpp

ArduPlane/sensors.pde

@@ -8,8 +8,6 @@ void ReadSCP1000(void) {}
 static void init_barometer(void)
 {
     barometer.calibrate(mavlink_delay);
-	g.ground_pressure.set_and_save(barometer.get_ground_pressure());
-	g.ground_temperature.set_and_save(barometer.get_ground_temperature() / 10.0f);
     ahrs.set_barometer(&barometer);
     gcs_send_text_P(SEVERITY_LOW, PSTR("barometer calibration complete"));
 }

libraries/AP_Baro/AP_Baro.cpp

@@ -12,6 +12,22 @@
 #include <AP_Common.h>
 #include <AP_Baro.h>
 
+// table of user settable parameters
+const AP_Param::GroupInfo AP_Baro::var_info[] PROGMEM = {
+	// @Param: ABS_PRESS
+	// @DisplayName: Absolute Pressure
+	// @Description: calibrated ground pressure
+	// @Increment: 1
+    AP_GROUPINFO("ABS_PRESS", 0, AP_Baro, _ground_pressure),
+
+	// @Param: ABS_PRESS
+	// @DisplayName: ground temperature
+	// @Description: calibrated ground temperature
+	// @Increment: 1
+    AP_GROUPINFO("TEMP", 1, AP_Baro, _ground_temperature),
+    AP_GROUPEND
+};
+
 // calibrate the barometer. This must be called at least once before
 // the altitude() or climb_rate() interfaces can be used
 void AP_Baro::calibrate(void (*callback)(unsigned long t))

libraries/AP_Baro/AP_Baro.h

@@ -38,6 +38,8 @@ class AP_Baro
     int16_t get_ground_temperature(void) { return _ground_temperature.get(); }
     int32_t get_ground_pressure(void) { return _ground_pressure.get(); }
 
+	static const struct AP_Param::GroupInfo var_info[];
+
 protected:
     uint32_t _last_update;