AC_PrecLand: added BUS parameter for precision landing

allow selection of i2c bus for irlock

libraries/AC_PrecLand/AC_PrecLand.cpp

@@ -83,6 +83,13 @@ const AP_Param::GroupInfo AC_PrecLand::var_info[] = {
     // @User: Advanced
     AP_GROUPINFO("CAM_POS", 7, AC_PrecLand, _cam_offset, 0.0f),
 
+    // @Param: BUS
+    // @DisplayName: Sensor Bus
+    // @Description: Precland sensor bus for I2C sensors.
+    // @Values: -1:DefaultBus,0:InternalI2C,1:ExternalI2C
+    // @User: Advanced
+    AP_GROUPINFO("BUS",    8, AC_PrecLand, _bus, -1),
+    
     AP_GROUPEND
 };
 

libraries/AC_PrecLand/AC_PrecLand.h

@@ -107,6 +107,7 @@ private:
     // parameters
     AP_Int8                     _enabled;           // enabled/disabled and behaviour
     AP_Int8                     _type;              // precision landing sensor type
+    AP_Int8                     _bus;               // which sensor bus
     AP_Int8                     _estimator_type;    // precision landing estimator type
     AP_Float                    _yaw_align;         // Yaw angle from body x-axis to sensor x-axis.
     AP_Float                    _land_ofs_cm_x;     // Desired landing position of the camera forward of the target in vehicle body frame

libraries/AC_PrecLand/AC_PrecLand_Backend.h

@@ -39,6 +39,9 @@ public:
     // parses a mavlink message from the companion computer
     virtual void handle_msg(mavlink_message_t* msg) {};
 
+    // get bus parameter
+    int8_t get_bus(void) const { return _frontend._bus.get(); }
+    
 protected:
     const AC_PrecLand&  _frontend;          // reference to precision landing front end
     AC_PrecLand::precland_state &_state;    // reference to this instances state

libraries/AC_PrecLand/AC_PrecLand_IRLock.cpp

@@ -15,7 +15,7 @@ AC_PrecLand_IRLock::AC_PrecLand_IRLock(const AC_PrecLand& frontend, AC_PrecLand:
 // init - perform initialisation of this backend
 void AC_PrecLand_IRLock::init()
 {
-    irlock.init();
+    irlock.init(get_bus());
 }
 
 // update - give chance to driver to get updates from sensor

libraries/AC_PrecLand/AC_PrecLand_SITL_Gazebo.cpp

@@ -15,7 +15,7 @@ AC_PrecLand_SITL_Gazebo::AC_PrecLand_SITL_Gazebo(const AC_PrecLand& frontend, AC
 // init - perform initialisation of this backend
 void AC_PrecLand_SITL_Gazebo::init()
 {
-    irlock.init();
+    irlock.init(get_bus());
 }
 
 // update - give chance to driver to get updates from sensor