Compass Ordering Improvement

ArduCopter/AP_Arming.cpp

@@ -91,8 +91,9 @@ bool AP_Arming_Copter::compass_checks(bool display_failure)
     if ((checks_to_perform == ARMING_CHECK_ALL) || (checks_to_perform & ARMING_CHECK_COMPASS)) {
         // check compass offsets have been set.  AP_Arming only checks
         // this if learning is off; Copter *always* checks.
-        if (!AP::compass().configured()) {
-            check_failed(ARMING_CHECK_COMPASS, display_failure, "Compass not calibrated");
+        char failure_msg[50] = {};
+        if (!AP::compass().configured(failure_msg, ARRAY_SIZE(failure_msg))) {
+            check_failed(ARMING_CHECK_COMPASS, display_failure, "%s", failure_msg);
             ret = false;
         }
     }

ArduCopter/compassmot.cpp

@@ -221,10 +221,10 @@ MAV_RESULT Copter::mavlink_compassmot(const GCS_MAVLINK &gcs_chan)
             mavlink_msg_compassmot_status_send(gcs_chan.get_chan(),
                                                channel_throttle->get_control_in(),
                                                current,
-                                               interference_pct[compass.get_primary()],
-                                               motor_compensation[compass.get_primary()].x,
-                                               motor_compensation[compass.get_primary()].y,
-                                               motor_compensation[compass.get_primary()].z);
+                                               interference_pct[0],
+                                               motor_compensation[0].x,
+                                               motor_compensation[0].y,
+                                               motor_compensation[0].z);
         }
     }
 

libraries/AP_Arming/AP_Arming.cpp

@@ -384,7 +384,7 @@ bool AP_Arming::compass_checks(bool report)
 
         // avoid Compass::use_for_yaw(void) as it implicitly calls healthy() which can
         // incorrectly skip the remaining checks, pass the primary instance directly
-        if (!_compass.use_for_yaw(_compass.get_primary())) {
+        if (!_compass.use_for_yaw(0)) {
             // compass use is disabled
             return true;
         }
@@ -394,9 +394,12 @@ bool AP_Arming::compass_checks(bool report)
             return false;
         }
         // check compass learning is on or offsets have been set
-        if (!_compass.learn_offsets_enabled() && !_compass.configured()) {
-            check_failed(ARMING_CHECK_COMPASS, report, "Compass not calibrated");
-            return false;
+        if (!_compass.learn_offsets_enabled()) {
+            char failure_msg[50] = {};
+            if (!_compass.configured(failure_msg, ARRAY_SIZE(failure_msg))) {
+                check_failed(ARMING_CHECK_COMPASS, report, "%s", failure_msg);
+                return false;
+            }
         }
 
         // check for unreasonable compass offsets