AP_Mount: allow users to disable yaw on 3-axis gimbals

Also fixes 3-axis gimbal support for SToRM32 serial and MAVLink gimbals

libraries/AP_Mount/AP_Mount_Alexmos.cpp

@@ -99,7 +99,7 @@ void AP_Mount_Alexmos::update()
 // has_pan_control - returns true if this mount can control it's pan (required for multicopters)
 bool AP_Mount_Alexmos::has_pan_control() const
 {
-    return _gimbal_3axis;
+    return _gimbal_3axis && yaw_range_valid();
 }
 
 // get attitude as a quaternion.  returns true on success

libraries/AP_Mount/AP_Mount_Backend.h

@@ -46,7 +46,7 @@ public:
     // return true if healthy
     virtual bool healthy() const { return true; }
 
-    // has_pan_control - returns true if this mount can control it's pan (required for multicopters)
+    // returns true if this mount can control its pan (required for multicopters)
     virtual bool has_pan_control() const = 0;
 
     // get mount's mode
@@ -115,6 +115,10 @@ protected:
         bool yaw_is_ef;
     };
 
+    // returns true if user has configured a valid yaw angle range
+    // allows user to disable yaw even on 3-axis gimbal
+    bool yaw_range_valid() const { return (_state._pan_angle_min < _state._pan_angle_max); }
+
     // returns true if mavlink heartbeat should be suppressed for this gimbal (only used by Solo gimbal)
     virtual bool suppress_heartbeat() const { return false; }
 

libraries/AP_Mount/AP_Mount_Gremsy.h

@@ -34,7 +34,7 @@ public:
     bool healthy() const override;
 
     // has_pan_control
-    bool has_pan_control() const override { return true; }
+    bool has_pan_control() const override { return yaw_range_valid(); }
 
     // handle GIMBAL_DEVICE_INFORMATION message
     void handle_gimbal_device_information(const mavlink_message_t &msg) override;

libraries/AP_Mount/AP_Mount_SToRM32.cpp

@@ -104,13 +104,6 @@ void AP_Mount_SToRM32::update()
     }
 }
 
-// has_pan_control - returns true if this mount can control it's pan (required for multicopters)
-bool AP_Mount_SToRM32::has_pan_control() const
-{
-    // we do not have yaw control
-    return false;
-}
-
 // set_mode - sets mount's mode
 void AP_Mount_SToRM32::set_mode(enum MAV_MOUNT_MODE mode)
 {

libraries/AP_Mount/AP_Mount_SToRM32.h

@@ -30,7 +30,7 @@ public:
     void update() override;
 
     // has_pan_control - returns true if this mount can control it's pan (required for multicopters)
-    bool has_pan_control() const override;
+    bool has_pan_control() const override { return yaw_range_valid(); }
 
     // set_mode - sets mount's mode
     void set_mode(enum MAV_MOUNT_MODE mode) override;

libraries/AP_Mount/AP_Mount_SToRM32_serial.cpp

@@ -133,13 +133,6 @@ void AP_Mount_SToRM32_serial::update()
     }
 }
 
-// has_pan_control - returns true if this mount can control it's pan (required for multicopters)
-bool AP_Mount_SToRM32_serial::has_pan_control() const
-{
-    // we do not have yaw control
-    return false;
-}
-
 // set_mode - sets mount's mode
 void AP_Mount_SToRM32_serial::set_mode(enum MAV_MOUNT_MODE mode)
 {

libraries/AP_Mount/AP_Mount_SToRM32_serial.h

@@ -33,7 +33,7 @@ public:
     void update() override;
 
     // has_pan_control - returns true if this mount can control it's pan (required for multicopters)
-    bool has_pan_control() const override;
+    bool has_pan_control() const override { return yaw_range_valid(); };
 
     // set_mode - sets mount's mode
     void set_mode(enum MAV_MOUNT_MODE mode) override;

libraries/AP_Mount/AP_Mount_Servo.cpp

@@ -117,7 +117,7 @@ void AP_Mount_Servo::update()
 // returns true if this mount can control its pan (required for multicopters)
 bool AP_Mount_Servo::has_pan_control() const
 {
-    return SRV_Channels::function_assigned(_pan_idx);
+    return SRV_Channels::function_assigned(_pan_idx) && yaw_range_valid();
 }
 
 // get attitude as a quaternion.  returns true on success