APM: Added STICK_MIXING option

this replaces the compile time option. Disabling during long distance
flights when the transmitter may be out of range is useful.

ArduPlane/Attitude.pde

@@ -64,7 +64,7 @@ static void stabilize()
 	// Mix Stick input to allow users to override control surfaces
 	// -----------------------------------------------------------
 	if ((control_mode < FLY_BY_WIRE_A) ||
-        (ENABLE_STICK_MIXING == 1 &&
+        (g.stick_mixing &&
          geofence_stickmixing() &&
          control_mode > FLY_BY_WIRE_B &&
          failsafe == FAILSAFE_NONE)) {
@@ -98,7 +98,7 @@ static void stabilize()
 	// important for steering on the ground during landing
 	// -----------------------------------------------
 	if (control_mode <= FLY_BY_WIRE_B ||
-        (ENABLE_STICK_MIXING == 1 &&
+        (g.stick_mixing && 
          geofence_stickmixing() &&
          failsafe == FAILSAFE_NONE)) {
 		ch4_inf = (float)g.channel_rudder.radio_in - (float)g.channel_rudder.radio_trim;

ArduPlane/GCS_Mavlink.pde

@@ -70,13 +70,11 @@ static NOINLINE void send_heartbeat(mavlink_channel_t chan)
         base_mode |= MAV_MODE_FLAG_STABILIZE_ENABLED;
     }
 
-#if ENABLE_STICK_MIXING==ENABLED
-    if (control_mode != INITIALISING) {
+    if (g.stick_mixing && control_mode != INITIALISING) {
         // all modes except INITIALISING have some form of manual
         // override if stick mixing is enabled
         base_mode |= MAV_MODE_FLAG_MANUAL_INPUT_ENABLED;
     }
-#endif
 
 #if HIL_MODE != HIL_MODE_DISABLED
     base_mode |= MAV_MODE_FLAG_HIL_ENABLED;

ArduPlane/Parameters.h

@@ -69,6 +69,7 @@ public:
         k_param_manual_level,
 		k_param_land_pitch_cd,
 		k_param_ins,
+        k_param_stick_mixing,
 
 		// 110: Telemetry control
 		//
@@ -308,6 +309,7 @@ public:
 	AP_Int32	pack_capacity;		// Battery pack capacity less reserve
     AP_Int8		inverted_flight_ch; // 0=disabled, 1-8 is channel for inverted flight trigger
     AP_Int8		sonar_enabled;
+    AP_Int8		stick_mixing;
 
 	// Camera
 #if CAMERA == ENABLED

ArduPlane/Parameters.pde

@@ -65,6 +65,13 @@ const AP_Param::Info var_info[] PROGMEM = {
 	// @User: Advanced
 	GSCALAR(manual_level,           "MANUAL_LEVEL",   MANUAL_LEVEL),
 
+    // @Param: STICK_MIXING
+	// @DisplayName: Stick Mixing
+	// @Description: When enabled, this adds user stick input to the control surfaces in auto modes, allowing the user to have some degree of flight control without changing modes
+	// @Values: 0:Disabled,1:Enabled
+	// @User: Advanced
+	GSCALAR(stick_mixing,           "STICK_MIXING",   1),
+
 	// @Param: land_pitch_cd
 	// @DisplayName: Landing Pitch
 	// @Description: Used in autoland for planes without airspeed sensors in hundredths of a degree

ArduPlane/config.h

@@ -386,14 +386,6 @@
 #endif
 
 
-//////////////////////////////////////////////////////////////////////////////
-// ENABLE_STICK_MIXING
-//
-#ifndef ENABLE_STICK_MIXING
-# define ENABLE_STICK_MIXING	ENABLED
-#endif
-
-
 //////////////////////////////////////////////////////////////////////////////
 // THROTTLE_OUT
 //