add parameter wrapper macros for ros

src/examples/subscriber/subscriber.cpp

@@ -74,6 +74,14 @@ PX4_MAIN_FUNCTION(subscriber) {
 	 */
 	px4::NodeHandle n;
 
+	/* Define a parameter */
+	PX4_PARAM_INIT("SUB_INTERV", 100);
+
+	/* Read the parameter back for testing */
+	int32_t sub_interval;
+	PX4_PARAM_GET("SUB_INTERV", &sub_interval);
+	PX4_INFO("Param SUB_INTERV = %d", sub_interval);
+
 	/**
 	 * The subscribe() call is how you tell ROS that you want to receive messages
 	 * on a given topic.  This invokes a call to the ROS

src/platforms/px4_defines.h

@@ -51,6 +51,8 @@
 #define PX4_TOPIC_T(_name) _name
 #define PX4_SUBSCRIBE_CBMETH(_nodehandle, _name, _cbf, _obj, _interval) _nodehandle.subscribe(PX4_TOPIC(_name), &_cbf, &_obj);
 #define PX4_SUBSCRIBE_CBFUNC(_nodehandle, _name, _cbf, _interval) _nodehandle.subscribe(PX4_TOPIC(_name), _cbf);
+#define PX4_PARAM_INIT(_name, _default) ros::param::set(_name, _default);
+#define PX4_PARAM_GET(_name, _destpt) ros::param::get(_name, *_destpt)
 #else
 /*
  * Building for NuttX