[fixewing][modules] convert nav_spiral to module

conf/airframes/examples/Twinstar_energyadaptive.xml

@@ -164,7 +164,6 @@ twog_1.0 + aspirin + ETS baro + ETS speed
     <define name="NO_XBEE_API_INIT" value="TRUE"/>
     <define name="TRIGGER_DELAY" value="1."/>
     <define name="DEFAULT_CIRCLE_RADIUS" value="70."/>
-    <define name="MIN_CIRCLE_RADIUS" value="35.0"/>
   </section>
 
   <section name="GLS_APPROACH" prefix="APP_">

conf/airframes/flixr_discovery.xml

@@ -227,9 +227,6 @@
 
     <define name="DEFAULT_CIRCLE_RADIUS" value="50.0"/>
 
-    <!-- only for spiral -->
-    <define name="MIN_CIRCLE_RADIUS" value="35.0"/>
-
     <!-- The Glide definitions are used for calculating the touch down point during auto landing -->
     <!--
     -->

conf/firmwares/subsystems/fixedwing/navigation_extra.makefile

@@ -14,7 +14,6 @@ $(TARGET).srcs += $(SRC_SUBSYSTEMS)/navigation/nav_survey_rectangle.c $(SRC_SUBS
 $(TARGET).srcs += $(SRC_SUBSYSTEMS)/navigation/discsurvey.c
 $(TARGET).srcs += $(SRC_SUBSYSTEMS)/navigation/OSAMNav.c
 $(TARGET).srcs += $(SRC_SUBSYSTEMS)/navigation/snav.c
-$(TARGET).srcs += $(SRC_SUBSYSTEMS)/navigation/spiral.c
 $(TARGET).srcs += $(SRC_SUBSYSTEMS)/navigation/poly_survey_adv.c
 $(TARGET).srcs += $(SRC_SUBSYSTEMS)/navigation/gls.c
 $(TARGET).srcs += $(SRC_SUBSYSTEMS)/navigation/border_line.c

conf/modules/nav_spiral.xml

@@ -0,0 +1,20 @@
+<!DOCTYPE module SYSTEM "module.dtd">
+
+<module name="nav_spiral" dir="nav">
+  <doc>
+    <description>
+      Fixedwing navigation in a spiral/helix.
+      creating a helix:
+      - start radius to end radius, increasing after reaching alphamax
+      - Alphamax is calculated from given segments
+      - IMPORTANT: numer of segments has to be larger than 2!
+    </description>
+    <define name="NAV_SPIRAL_MIN_CIRCLE_RADIUS" value="120" description="minium circle radius in meters"/>
+  </doc>
+  <header>
+    <file name="nav_spiral.h"/>
+  </header>
+  <makefile>
+    <file name="nav_spiral.c"/>
+  </makefile>
+</module>