Copter: allow CH6 tuning of compass declination

ArduCopter/ArduCopter.pde

@@ -2040,7 +2040,7 @@ static void update_trig(void){
     // 270 = cos_yaw:  0.00, sin_yaw: -1.00,
 }
 
-// read baro and sonar altitude at 10hz
+// read baro and sonar altitude at 20hz
 static void update_altitude()
 {
 #if HIL_MODE == HIL_MODE_ATTITUDE
@@ -2218,6 +2218,11 @@ static void tuning(){
     case CH6_THR_ACCEL_KD:
         g.pid_throttle_accel.kD(tuning_value);
         break;
+
+    case CH6_DECLINATION:
+        // set declination to +-20degrees
+        compass.set_declination(ToRad(20-g.rc_6.control_in/25), false);     // 2nd parameter is false because we do not want to save to eeprom because this would have a performance impact
+        break;
     }
 }
 

ArduCopter/Parameters.pde

@@ -368,7 +368,7 @@ const AP_Param::Info var_info[] PROGMEM = {
     // @DisplayName: Channel 6 Tuning
     // @Description: Controls which parameters (normally PID gains) are being tuned with transmitter's channel 6 knob
     // @User: Standard
-    // @Values: 0:CH6_NONE,1:CH6_STABILIZE_KP,2:CH6_STABILIZE_KI,3:CH6_YAW_KP,4:CH6_RATE_KP,5:CH6_RATE_KI,6:CH6_YAW_RATE_KP,7:CH6_THROTTLE_KP,8:CH6_TOP_BOTTOM_RATIO,9:CH6_RELAY,10:CH6_WP_SPEED,12:CH6_LOITER_KP,13:CH6_HELI_EXTERNAL_GYRO,14:CH6_THR_HOLD_KP,17:CH6_OPTFLOW_KP,18:CH6_OPTFLOW_KI,19:CH6_OPTFLOW_KD,21:CH6_RATE_KD,22:CH6_LOITER_RATE_KP,23:CH6_LOITER_RATE_KD,24:CH6_YAW_KI,25:CH6_ACRO_KP,26:CH6_YAW_RATE_KD,27:CH6_LOITER_KI,28:CH6_LOITER_RATE_KI,29:CH6_STABILIZE_KD,30:CH6_AHRS_YAW_KP,31:CH6_AHRS_KP,32:CH6_INAV_TC,33:CH6_THROTTLE_KI,34:CH6_THR_ACCEL_KP,35:CH6_THR_ACCEL_KI,36:CH6_THR_ACCEL_KD
+    // @Values: 0:CH6_NONE,1:CH6_STABILIZE_KP,2:CH6_STABILIZE_KI,3:CH6_YAW_KP,4:CH6_RATE_KP,5:CH6_RATE_KI,6:CH6_YAW_RATE_KP,7:CH6_THROTTLE_KP,8:CH6_TOP_BOTTOM_RATIO,9:CH6_RELAY,10:CH6_WP_SPEED,12:CH6_LOITER_KP,13:CH6_HELI_EXTERNAL_GYRO,14:CH6_THR_HOLD_KP,17:CH6_OPTFLOW_KP,18:CH6_OPTFLOW_KI,19:CH6_OPTFLOW_KD,21:CH6_RATE_KD,22:CH6_LOITER_RATE_KP,23:CH6_LOITER_RATE_KD,24:CH6_YAW_KI,25:CH6_ACRO_KP,26:CH6_YAW_RATE_KD,27:CH6_LOITER_KI,28:CH6_LOITER_RATE_KI,29:CH6_STABILIZE_KD,30:CH6_AHRS_YAW_KP,31:CH6_AHRS_KP,32:CH6_INAV_TC,33:CH6_THROTTLE_KI,34:CH6_THR_ACCEL_KP,35:CH6_THR_ACCEL_KI,36:CH6_THR_ACCEL_KD,38:CH6_DECLINATION
     GSCALAR(radio_tuning, "TUNE",                   0),
 
     // @Param: TUNE_LOW

ArduCopter/defines.h

@@ -174,6 +174,7 @@
 #define CH6_AHRS_YAW_KP     30          // ahrs's compass effect on yaw angle (0 = very low, 1 = very high)
 #define CH6_AHRS_KP         31          // accelerometer effect on roll/pitch angle (0=low)
 #define CH6_INAV_TC         32          // inertial navigation baro/accel and gps/accel time constant (1.5 = strong baro/gps correction on accel estimatehas very strong does not correct accel estimate, 7 = very weak correction)
+#define CH6_DECLINATION     38          // compass declination in radians
 
 
 // Commands - Note that APM now uses a subset of the MAVLink protocol
@@ -286,6 +287,7 @@ enum gcs_severity {
 #define LOG_DATA_INT32_MSG              0x16
 #define LOG_DATA_UINT32_MSG             0x17
 #define LOG_DATA_FLOAT_MSG              0x18
+#define LOG_WPNAV_MSG                   0x19
 #define LOG_INDEX_MSG                   0xF0
 #define MAX_NUM_LOGS                    50
 

ArduCopter/radio.pde

@@ -16,6 +16,7 @@ static void default_dead_zones()
     g.rc_3.set_dead_zone(60);
     g.rc_4.set_dead_zone(80);
 #endif
+    g.rc_6.set_dead_zone(0);
 }
 
 static void init_rc_in()

libraries/AP_Compass/Compass.cpp

@@ -159,9 +159,13 @@ Compass::set_initial_location(int32_t latitude, int32_t longitude)
 }
 
 void
-Compass::set_declination(float radians)
+Compass::set_declination(float radians, bool save_to_eeprom)
 {
+    if (save_to_eeprom) {
         _declination.set_and_save(radians);
+    }else{
+        _declination.set(radians);
+    }
 }
 
 float

libraries/AP_Compass/Compass.h

@@ -122,8 +122,9 @@ public:
     /// Sets the local magnetic field declination.
     ///
     /// @param  radians             Local field declination.
+    /// @param save_to_eeprom       true to save to eeprom (false saves only to memory)
     ///
-    void set_declination(float radians);
+    void set_declination(float radians, bool save_to_eeprom = true);
     float get_declination();
 
     // set overall board orientation