Copter: add EKFCHECK_COMPASS parameter

ArduCopter/Parameters.h

@@ -115,8 +115,9 @@ public:
         k_param_serial0_baud,
         k_param_serial1_baud,
         k_param_serial2_baud,
-        k_param_land_repositioning,     // 52
+        k_param_land_repositioning,
         k_param_sonar, // sonar object
+        k_param_ekfcheck_compass_thresh,// 54
 
         // 65: AP_Limits Library
         k_param_limits = 65,            // deprecated - remove
@@ -383,6 +384,7 @@ public:
     AP_Int8         arming_check;
 
     AP_Int8         land_repositioning;
+    AP_Float        ekfcheck_compass_thresh;
 
 #if FRAME_CONFIG ==     HELI_FRAME
     // Heli

ArduCopter/Parameters.pde

@@ -435,6 +435,13 @@ const AP_Param::Info var_info[] PROGMEM = {
     // @User: Advanced
     GSCALAR(land_repositioning, "LAND_REPOSITION",     LAND_REPOSITION_DEFAULT),
 
+    // @Param: EKFCHECK_COMPASS
+    // @DisplayName: EKF checker compass variance threshold
+    // @Description: Allows setting the maximum acceptable compass/magnetometer variance (0 to disable check)
+    // @Values: 0:Disabled, 0.6:Default, 1.0:Relaxed
+    // @User: Advanced
+    GSCALAR(ekfcheck_compass_thresh, "EKFCHECK_COMPASS", EKFCHECK_COMPASS_THRESHOLD_DEFAULT),
+
 #if FRAME_CONFIG ==     HELI_FRAME
     // @Group: HS1_
     // @Path: ../libraries/RC_Channel/RC_Channel.cpp

ArduCopter/config.h

@@ -337,6 +337,12 @@
  # define PREARM_MAX_VELOCITY_CMS           50.0f   // vehicle must be travelling under 50cm/s before arming
 #endif
 
+//////////////////////////////////////////////////////////////////////////////
+//  EKF Checker
+#ifndef EKFCHECK_COMPASS_THRESHOLD_DEFAULT
+ # define EKFCHECK_COMPASS_THRESHOLD_DEFAULT    0.6f    // EKF checker's default compass variance above which the EKF's horizontal position will be considered bad
+#endif
+
 //////////////////////////////////////////////////////////////////////////////
 //  MAGNETOMETER
 #ifndef MAGNETOMETER