Rover: Save compass offsets when disarmed and learning is on

APMrover2/APMrover2.cpp

@@ -79,6 +79,7 @@ const AP_Scheduler::Task Rover::scheduler_tasks[] = {
     SCHED_TASK_CLASS(AP_Notify,           &rover.notify,           update,         50,  300),
     SCHED_TASK(one_second_loop,         1,   1500),
     SCHED_TASK(compass_cal_update,     50,    200),
+    SCHED_TASK(compass_save,           0.1,   200),
     SCHED_TASK(accel_cal_update,       10,    200),
 #if LOGGING_ENABLED == ENABLED
     SCHED_TASK_CLASS(DataFlash_Class,     &rover.DataFlash,        periodic_tasks, 50,  300),
@@ -273,18 +274,6 @@ void Rover::one_second_loop(void)
     // cope with changes to mavlink system ID
     mavlink_system.sysid = g.sysid_this_mav;
 
-    static uint8_t counter;
-
-    counter++;
-
-    // save compass offsets once a minute
-    if (counter >= 60) {
-        if (g.compass_enabled) {
-            compass.save_offsets();
-        }
-        counter = 0;
-    }
-
     // update home position if not soft armed and gps position has
     // changed. Update every 1s at most
     if (!hal.util->get_soft_armed() &&

APMrover2/Rover.h

@@ -506,6 +506,7 @@ private:
     void update_visual_odom();
     void update_wheel_encoder();
     void compass_cal_update(void);
+    void compass_save(void);
     void accel_cal_update(void);
     void read_rangefinders(void);
     void init_proximity();

APMrover2/sensors.cpp

@@ -152,6 +152,15 @@ void Rover::compass_cal_update() {
     }
 }
 
+// Save compass offsets
+void Rover::compass_save() {
+    if (g.compass_enabled &&
+        compass.get_learn_type() >= Compass::LEARN_INTERNAL &&
+        !arming.is_armed()) {
+        compass.save_offsets();
+    }
+}
+
 // Accel calibration
 
 void Rover::accel_cal_update() {