diff --git a/libraries/AP_Mount/AP_Mount_SToRM32_serial.cpp b/libraries/AP_Mount/AP_Mount_SToRM32_serial.cpp
index 9dba14ea82..7e7d2d417b 100644
--- a/libraries/AP_Mount/AP_Mount_SToRM32_serial.cpp
+++ b/libraries/AP_Mount/AP_Mount_SToRM32_serial.cpp
@@ -42,59 +42,66 @@ void AP_Mount_SToRM32_serial::update()
     // update based on mount mode
     switch(get_mode()) {
         // move mount to a "retracted" position.  To-Do: remove support and replace with a relaxed mode?
-        case MAV_MOUNT_MODE_RETRACT:
-            {
+        case MAV_MOUNT_MODE_RETRACT: {
             const Vector3f &target = _state._retract_angles.get();
-            _angle_ef_target_rad.x = ToRad(target.x);
-            _angle_ef_target_rad.y = ToRad(target.y);
-            _angle_ef_target_rad.z = ToRad(target.z);
-            }
+            _angle_rad.roll = ToRad(target.x);
+            _angle_rad.pitch = ToRad(target.y);
+            _angle_rad.yaw = ToRad(target.z);
+            _angle_rad.yaw_is_ef = false;
             break;
+        }
 
         // move mount to a neutral position, typically pointing forward
-        case MAV_MOUNT_MODE_NEUTRAL:
-            {
+        case MAV_MOUNT_MODE_NEUTRAL: {
             const Vector3f &target = _state._neutral_angles.get();
-            _angle_ef_target_rad.x = ToRad(target.x);
-            _angle_ef_target_rad.y = ToRad(target.y);
-            _angle_ef_target_rad.z = ToRad(target.z);
-            }
+            _angle_rad.roll = ToRad(target.x);
+            _angle_rad.pitch = ToRad(target.y);
+            _angle_rad.yaw = ToRad(target.z);
+            _angle_rad.yaw_is_ef = false;
             break;
+        }
 
         // point to the angles given by a mavlink message
         case MAV_MOUNT_MODE_MAVLINK_TARGETING:
-            // do nothing because earth-frame angle targets (i.e. _angle_ef_target_rad) should have already been set by a MOUNT_CONTROL message from GCS
+            switch (mavt_target.target_type) {
+            case MountTargetType::ANGLE:
+                _angle_rad = mavt_target.angle_rad;
+                break;
+            case MountTargetType::RATE:
+                update_angle_target_from_rate(mavt_target.rate_rads, _angle_rad);
+                break;
+            }
             resend_now = true;
             break;
 
         // RC radio manual angle control, but with stabilization from the AHRS
-        case MAV_MOUNT_MODE_RC_TARGETING:
-            // update targets using pilot's rc inputs
-            update_targets_from_rc();
+        case MAV_MOUNT_MODE_RC_TARGETING: {
+            // update targets using pilot's RC inputs
+            MountTarget rc_target {};
+            if (get_rc_rate_target(rc_target)) {
+                update_angle_target_from_rate(rc_target, _angle_rad);
+            } else if (get_rc_angle_target(rc_target)) {
+                _angle_rad = rc_target;
+            }
             resend_now = true;
             break;
+        }
 
         // point mount to a GPS point given by the mission planner
         case MAV_MOUNT_MODE_GPS_POINT:
-            if (calc_angle_to_roi_target(_angle_ef_target_rad, true, true, true)) {
+            if (get_angle_target_to_roi(_angle_rad)) {
                 resend_now = true;
             }
             break;
 
         case MAV_MOUNT_MODE_HOME_LOCATION:
-            // constantly update the home location:
-            if (!AP::ahrs().home_is_set()) {
-                break;
-            }
-            _roi_target = AP::ahrs().get_home();
-            _roi_target_set = true;
-            if (calc_angle_to_roi_target(_angle_ef_target_rad, true, true, true)) {
+            if (get_angle_target_to_home(_angle_rad)) {
                 resend_now = true;
             }
             break;
 
         case MAV_MOUNT_MODE_SYSID_TARGET:
-            if (calc_angle_to_sysid_target(_angle_ef_target_rad, true, true, true)) {
+            if (get_angle_target_to_sysid(_angle_rad)) {
                 resend_now = true;
             }
             break;
@@ -112,7 +119,7 @@ void AP_Mount_SToRM32_serial::update()
     }
     if (can_send(resend_now)) {
         if (resend_now) {
-            send_target_angles(ToDeg(_angle_ef_target_rad.y), ToDeg(_angle_ef_target_rad.x), ToDeg(_angle_ef_target_rad.z));
+            send_target_angles(_angle_rad);
             get_angles();
             _reply_type = ReplyType_ACK;
             _reply_counter = 0;
@@ -162,7 +169,7 @@ bool AP_Mount_SToRM32_serial::can_send(bool with_control) {
 
 
 // send_target_angles
-void AP_Mount_SToRM32_serial::send_target_angles(float pitch_deg, float roll_deg, float yaw_deg)
+void AP_Mount_SToRM32_serial::send_target_angles(const MountTarget& angle_target_rad)
 {
 
     static cmd_set_angles_struct cmd_set_angles_data = {
@@ -186,14 +193,10 @@ void AP_Mount_SToRM32_serial::send_target_angles(float pitch_deg, float roll_deg
         return;
     }
 
-    // reverse pitch and yaw control
-    pitch_deg = -pitch_deg;
-    yaw_deg = -yaw_deg;
-
-    // send CMD_SETANGLE
-    cmd_set_angles_data.pitch = pitch_deg;
-    cmd_set_angles_data.roll = roll_deg;
-    cmd_set_angles_data.yaw = yaw_deg;
+    // send CMD_SETANGLE (Note: reversed pitch and yaw)
+    cmd_set_angles_data.pitch = -degrees(angle_target_rad.pitch);
+    cmd_set_angles_data.roll = degrees(angle_target_rad.roll);
+    cmd_set_angles_data.yaw = -degrees(get_bf_yaw_angle(angle_target_rad));
 
     uint8_t* buf = (uint8_t*)&cmd_set_angles_data;
 
diff --git a/libraries/AP_Mount/AP_Mount_SToRM32_serial.h b/libraries/AP_Mount/AP_Mount_SToRM32_serial.h
index 188f342637..1fb49c1cc5 100644
--- a/libraries/AP_Mount/AP_Mount_SToRM32_serial.h
+++ b/libraries/AP_Mount/AP_Mount_SToRM32_serial.h
@@ -44,7 +44,7 @@ public:
 private:
 
     // send_target_angles
-    void send_target_angles(float pitch_deg, float roll_deg, float yaw_deg);
+    void send_target_angles(const MountTarget& angle_target_rad);
 
     // send read data request
     void get_angles();
@@ -137,6 +137,7 @@ private:
     AP_HAL::UARTDriver *_port;
 
     bool _initialised;              // true once the driver has been initialised
+    MountTarget _angle_rad;         // latest angle target
     uint32_t _last_send;            // system time of last do_mount_control sent to gimbal
 
     uint8_t _reply_length;