diff --git a/ArduPlane/ArduPlane.pde b/ArduPlane/ArduPlane.pde
index 51129c1a40..7fce1772d7 100644
--- a/ArduPlane/ArduPlane.pde
+++ b/ArduPlane/ArduPlane.pde
@@ -136,95 +136,88 @@ static GPS         *g_gps;
 // flight modes convenience array
 static AP_Int8          *flight_modes = &g.flight_mode1;
 
-#if HIL_MODE == HIL_MODE_DISABLED
-
-// real sensors
- #if CONFIG_ADC == ENABLED
+#if CONFIG_ADC == ENABLED
 static AP_ADC_ADS7844 adc;
- #endif
-
- # if CONFIG_HAL_BOARD == HAL_BOARD_AVR_SITL
-AP_Baro_BMP085_HIL barometer;
-AP_Compass_HIL compass;
-AP_InertialSensor_Stub ins;
-SITL sitl;
- #else
+#endif
 
-  #if CONFIG_BARO == AP_BARO_BMP085
+#if CONFIG_BARO == AP_BARO_BMP085
 static AP_Baro_BMP085 barometer;
-  #elif CONFIG_BARO == AP_BARO_PX4
+#elif CONFIG_BARO == AP_BARO_PX4
 static AP_Baro_PX4 barometer;
-  #elif CONFIG_BARO == AP_BARO_MS5611
-   #if CONFIG_MS5611_SERIAL == AP_BARO_MS5611_SPI
-static AP_Baro_MS5611 barometer(&AP_Baro_MS5611::spi);
-   #elif CONFIG_MS5611_SERIAL == AP_BARO_MS5611_I2C
-static AP_Baro_MS5611 barometer(&AP_Baro_MS5611::i2c);
-   #else
-    #error Unrecognized CONFIG_MS5611_SERIAL setting.
-   #endif
-  #endif
-
-#if CONFIG_HAL_BOARD == HAL_BOARD_PX4
-static AP_Compass_PX4 compass;
+#elif CONFIG_BARO == AP_BARO_HIL
+static AP_Baro_BMP085_HIL barometer;
+#elif CONFIG_BARO == AP_BARO_MS5611
+ #if CONFIG_MS5611_SERIAL == AP_BARO_MS5611_SPI
+ static AP_Baro_MS5611 barometer(&AP_Baro_MS5611::spi);
+ #elif CONFIG_MS5611_SERIAL == AP_BARO_MS5611_I2C
+ static AP_Baro_MS5611 barometer(&AP_Baro_MS5611::i2c);
+ #else
+ #error Unrecognized CONFIG_MS5611_SERIAL setting.
+ #endif
 #else
+ #error Unrecognized CONFIG_BARO setting
+#endif
+
+#if CONFIG_COMPASS == AP_COMPASS_PX4
+static AP_Compass_PX4 compass;
+#elif CONFIG_COMPASS == AP_COMPASS_HMC5843
 static AP_Compass_HMC5843 compass;
+#elif CONFIG_COMPASS == AP_COMPASS_HIL
+static AP_Compass_HIL compass;
+#else
+ #error Unrecognized CONFIG_COMPASS setting
 #endif
- #endif
 
-// real GPS selection
- #if   GPS_PROTOCOL == GPS_PROTOCOL_AUTO
+// GPS selection
+#if   GPS_PROTOCOL == GPS_PROTOCOL_AUTO
 AP_GPS_Auto     g_gps_driver(&g_gps);
 
- #elif GPS_PROTOCOL == GPS_PROTOCOL_NMEA
-AP_GPS_NMEA     g_gps_driver();
+#elif GPS_PROTOCOL == GPS_PROTOCOL_NMEA
+AP_GPS_NMEA     g_gps_driver;
 
- #elif GPS_PROTOCOL == GPS_PROTOCOL_SIRF
-AP_GPS_SIRF     g_gps_driver();
+#elif GPS_PROTOCOL == GPS_PROTOCOL_SIRF
+AP_GPS_SIRF     g_gps_driver;
 
- #elif GPS_PROTOCOL == GPS_PROTOCOL_UBLOX
-AP_GPS_UBLOX    g_gps_driver();
+#elif GPS_PROTOCOL == GPS_PROTOCOL_UBLOX
+AP_GPS_UBLOX    g_gps_driver;
 
- #elif GPS_PROTOCOL == GPS_PROTOCOL_MTK
-AP_GPS_MTK      g_gps_driver();
+#elif GPS_PROTOCOL == GPS_PROTOCOL_MTK
+AP_GPS_MTK      g_gps_driver;
 
- #elif GPS_PROTOCOL == GPS_PROTOCOL_MTK19
-AP_GPS_MTK19    g_gps_driver();
+#elif GPS_PROTOCOL == GPS_PROTOCOL_MTK19
+AP_GPS_MTK19    g_gps_driver;
 
- #elif GPS_PROTOCOL == GPS_PROTOCOL_NONE
-AP_GPS_None     g_gps_driver();
+#elif GPS_PROTOCOL == GPS_PROTOCOL_NONE
+AP_GPS_None     g_gps_driver;
 
- #else
+#elif GPS_PROTOCOL == GPS_PROTOCOL_HIL
+AP_GPS_HIL      g_gps_driver;
+
+#else
   #error Unrecognised GPS_PROTOCOL setting.
- #endif // GPS PROTOCOL
+#endif // GPS PROTOCOL
 
- # if CONFIG_INS_TYPE == CONFIG_INS_MPU6000
+#if CONFIG_INS_TYPE == CONFIG_INS_MPU6000
 AP_InertialSensor_MPU6000 ins;
- # elif CONFIG_INS_TYPE == CONFIG_INS_PX4
+#elif CONFIG_INS_TYPE == CONFIG_INS_PX4
 AP_InertialSensor_PX4 ins;
- # elif CONFIG_HAL_BOARD != HAL_BOARD_AVR_SITL
+#elif CONFIG_INS_TYPE == CONFIG_INS_STUB
+AP_InertialSensor_Stub ins;
+#elif CONFIG_INS_TYPE == CONFIG_INS_OILPAN
 AP_InertialSensor_Oilpan ins( &adc );
- #endif // CONFIG_INS_TYPE
+#else
+  #error Unrecognised CONFIG_INS_TYPE setting.
+#endif // CONFIG_INS_TYPE
 
+#if HIL_MODE == HIL_MODE_ATTITUDE
+AP_AHRS_HIL ahrs(&ins, g_gps);
+#else
 AP_AHRS_DCM ahrs(&ins, g_gps);
+#endif
 
-#elif HIL_MODE == HIL_MODE_SENSORS
-// sensor emulators
-AP_Baro_BMP085_HIL barometer;
-AP_Compass_HIL compass;
-AP_GPS_HIL              g_gps_driver;
-AP_InertialSensor_Stub ins;
-AP_AHRS_DCM  ahrs(&ins, g_gps);
-
-#elif HIL_MODE == HIL_MODE_ATTITUDE
-AP_Baro_BMP085_HIL barometer;
-AP_Compass_HIL compass;
-AP_GPS_HIL              g_gps_driver;
-AP_InertialSensor_Stub ins;
-AP_AHRS_HIL   ahrs(&ins, g_gps);
-
-#else
- #error Unrecognised HIL_MODE setting.
-#endif // HIL MODE
+#if CONFIG_HAL_BOARD == HAL_BOARD_AVR_SITL
+SITL sitl;
+#endif
 
 // Training mode
 static bool training_manual_roll;  // user has manual roll control
diff --git a/ArduPlane/config.h b/ArduPlane/config.h
index be3d4bc703..251c52dd45 100644
--- a/ArduPlane/config.h
+++ b/ArduPlane/config.h
@@ -101,6 +101,7 @@
  # define CONFIG_PITOT_SOURCE PITOT_SOURCE_ADC
  # define CONFIG_PITOT_SOURCE_ADC_CHANNEL 7
  # define CONFIG_BARO     AP_BARO_BMP085
+ # define CONFIG_COMPASS  AP_COMPASS_HMC5843
 #elif CONFIG_HAL_BOARD == HAL_BOARD_APM2
  # define A_LED_PIN        27
  # define B_LED_PIN        26
@@ -126,6 +127,7 @@
  #  define CONFIG_BARO          AP_BARO_MS5611
  #  define CONFIG_MS5611_SERIAL AP_BARO_MS5611_SPI
  # endif
+ # define CONFIG_COMPASS  AP_COMPASS_HMC5843
 #elif CONFIG_HAL_BOARD == HAL_BOARD_AVR_SITL
  # define A_LED_PIN        27
  # define B_LED_PIN        26
@@ -139,6 +141,8 @@
  # define CONFIG_PITOT_SOURCE_ANALOG_PIN 0
  # define CONFIG_PITOT_SCALING 4.0
  # define MAGNETOMETER ENABLED
+ # define CONFIG_BARO     AP_BARO_HIL
+ # define CONFIG_COMPASS  AP_COMPASS_HIL
 #elif CONFIG_HAL_BOARD == HAL_BOARD_PX4
  # define A_LED_PIN        27
  # define B_LED_PIN        26
@@ -154,6 +158,7 @@
  # define MAGNETOMETER ENABLED
  # define MAG_ORIENTATION   ROTATION_NONE
  # define CONFIG_BARO AP_BARO_PX4
+ # define CONFIG_COMPASS  AP_COMPASS_PX4
  # define SERIAL0_BAUD 57600
 #endif
 
@@ -173,6 +178,10 @@
  # error "CONFIG_BARO not set"
 #endif
 
+#ifndef CONFIG_COMPASS
+ # error "CONFIG_COMPASS not set"
+#endif
+
 #ifndef CONFIG_PITOT_SOURCE
  # error "CONFIG_PITOT_SOURCE not set"
 #endif
@@ -185,14 +194,20 @@
 #endif
 
 #if HIL_MODE != HIL_MODE_DISABLED       // we are in HIL mode
- # undef GPS_PROTOCOL
- # define GPS_PROTOCOL GPS_PROTOCOL_NONE
+ #undef GPS_PROTOCOL
+ #define GPS_PROTOCOL GPS_PROTOCOL_HIL
+ #undef CONFIG_BARO
+ #define CONFIG_BARO AP_BARO_HIL
+ #undef CONFIG_INS_TYPE
+ #define CONFIG_INS_TYPE CONFIG_INS_STUB
  #undef CONFIG_ADC
  #define CONFIG_ADC DISABLED
  #undef CONFIG_PITOT_SOURCE
  #define CONFIG_PITOT_SOURCE PITOT_SOURCE_ANALOG_PIN
  #undef CONFIG_PITOT_SOURCE_ANALOG_PIN
  #define CONFIG_PITOT_SOURCE_ANALOG_PIN -1
+ #undef CONFIG_PITOT_SCALING
+ #define CONFIG_PITOT_SCALING 4.0
 #endif
 
 //////////////////////////////////////////////////////////////////////////////
diff --git a/ArduPlane/defines.h b/ArduPlane/defines.h
index 3dbb5a5668..44ae460a7b 100644
--- a/ArduPlane/defines.h
+++ b/ArduPlane/defines.h
@@ -224,13 +224,22 @@ enum log_messages {
 // mark a function as not to be inlined
 #define NOINLINE __attribute__((noinline))
 
-#define CONFIG_INS_OILPAN 1
+// InertialSensor driver types
+#define CONFIG_INS_OILPAN  1
 #define CONFIG_INS_MPU6000 2
-#define CONFIG_INS_STUB 3
+#define CONFIG_INS_STUB    3
+#define CONFIG_INS_PX4     4
 
+// barometer driver types
 #define AP_BARO_BMP085   1
 #define AP_BARO_MS5611   2
 #define AP_BARO_PX4      3
+#define AP_BARO_HIL      4
+
+// compass driver types
+#define AP_COMPASS_HMC5843   1
+#define AP_COMPASS_PX4       2
+#define AP_COMPASS_HIL       3
 
 // altitude control algorithms
 enum {