AP_Compass: added parameter for compass calibration fitness threshold

libraries/AP_Compass/AP_Compass_Calibration.cpp

@@ -47,9 +47,9 @@ Compass::start_calibration(uint8_t i, bool retry, bool autosave, float delay, bo
         AP_Notify::events.initiated_compass_cal = 1;
     }
     if (i == get_primary()) {
-        _calibrator[i].set_tolerance(8);
+        _calibrator[i].set_tolerance(_calibration_threshold);
     } else {
-        _calibrator[i].set_tolerance(16);
+        _calibrator[i].set_tolerance(_calibration_threshold*2);
     }
     _calibrator[i].start(retry, autosave, delay);
     _compass_cal_autoreboot = autoreboot;

libraries/AP_Compass/Compass.cpp

@@ -365,6 +365,14 @@ const AP_Param::GroupInfo Compass::var_info[] PROGMEM = {
     AP_GROUPINFO("ODI3",    29, Compass, _state[2].offdiagonals, 0),
 #endif
 
+    // @Param: CAL_FIT
+    // @DisplayName: Compass calibration fitness
+    // @Description: This controls the fitness level required for a successful compass calibration. A lower value makes for a stricter fit (less likely to pass). This is the value used for the primary magnetometer. Other magnetometers get double the value.
+    // @Range: 4 20
+    // @Increment: 0.1
+    // @User: Advanced
+    AP_GROUPINFO("CAL_FIT", 30, Compass, _calibration_threshold, 8.0f),
+    
     AP_GROUPEND
 };
 

libraries/AP_Compass/Compass.h

@@ -406,6 +406,8 @@ private:
 
     // if we want HIL only
     bool _hil_mode:1;
+
+    AP_Float _calibration_threshold;
 };
 
 #include "AP_Compass_Backend.h"