started reviving settings via remote control, to use it add <subsystem name=settings type=rc/> to your airframe file

conf/airframes/flixr_discovery.xml

@@ -32,6 +32,7 @@ http://paparazzi.enac.fr/w/index.php?title=Theory_of_Operation
     <!-- Communication -->
     <subsystem name="telemetry" type="transparent"/>
     <subsystem name="radio_control" type="ppm"/>
+    <!--subsystem name="settings" type="rc"/-->
 
     <!-- Control -->
     <subsystem name="control" type="new"/>

conf/autopilot/subsystems/fixedwing/settings_rc.makefile

@@ -0,0 +1,6 @@
+# Hey Emacs, this is a -*- makefile -*-
+
+# change settings via Remote Control, e.g. tune your aircraft
+
+$(TARGET).srcs += rc_settings.c
+$(TARGET).CFLAGS += -DRADIO_CONTROL_SETTINGS

conf/settings/tuning_ins_rc.xml

@@ -0,0 +1,18 @@
+<!--<!DOCTYPE settings SYSTEM "settings.dtd">-->
+
+<!-- A conf to use to tune an A/C using only the rc -->
+
+<settings>
+
+  <rc_settings>
+    <rc_mode NAME="AUTO1">
+      <rc_setting VAR="ins_pitch_neutral" RANGE="0.2" RC="gain_1_up"    TYPE="float"/>
+      <rc_setting VAR="ins_roll_neutral"  RANGE="-0.2" RC="gain_1_down" TYPE="float"/>
+    </rc_mode>
+    <rc_mode NAME="AUTO2">
+      <rc_setting VAR="h_ctl_course_pgain" RANGE="0.5" RC="gain_1_up" TYPE="float"/>
+      <rc_setting VAR="flight_altitude" RANGE="-100" RC="gain_1_down" TYPE="float"/>
+    </rc_mode>
+  </rc_settings>
+
+</settings>

sw/airborne/rc_settings.c

@@ -25,8 +25,8 @@
 
 
 #include <inttypes.h>
-#include "rc_settings.h"
 #include "generated/radio.h"
+#include "rc_settings.h"
 #include "autopilot.h"
 #include "subsystems/nav.h"
 #include "subsystems/sensors/infrared.h"

sw/airborne/rc_settings.h

@@ -28,11 +28,8 @@
  *
  * The 'rc_control' section of a XML flight plan allows the user to change the
  * value of an autopilot internal variable through the rc transmitter.
- * C code is generated from this XML code (var/AC/inflight_calib.h). This
+ * This module handles the control of this setting mode.
- * module handles the control of this setting mode.
  *
- * Note that this functionnality is deprecated since datalink use is a lot more
- * easier ('dl_settings' section)
  */
 
 #ifndef RC_SETTINGS_H
@@ -46,6 +43,10 @@
 #define RC_SETTINGS_MODE_DOWN      1
 #define RC_SETTINGS_MODE_UP        2
 
+extern uint8_t rc_settings_mode;
+
+void rc_settings(bool_t mode_changed);
+
 #define RcSettingsOff() (rc_settings_mode==RC_SETTINGS_MODE_NONE)
 
 #define RC_SETTINGS_MODE_OF_PULSE(pprz) (pprz < TRESHOLD1 ? RC_SETTINGS_MODE_DOWN : \
@@ -55,9 +56,6 @@
 #define RcSettingsModeUpdate(_rc_channels) \
   ModeUpdate(rc_settings_mode, RC_SETTINGS_MODE_OF_PULSE(_rc_channels[RADIO_CALIB]))
 
-extern uint8_t rc_settings_mode;
-void rc_settings(bool_t mode_changed);
-
 
 #else /*  RADIO_CALIB && defined RADIO_CONTROL_SETTINGS */