Refactor air pressure demo

ros_gz_sim_demos/CMakeLists.txt

@@ -9,6 +9,12 @@ if(BUILD_TESTING)
   ament_lint_auto_find_test_dependencies()
 endif()
 
+install(
+  DIRECTORY
+    config/
+  DESTINATION share/${PROJECT_NAME}/config
+)
+
 install(
   DIRECTORY
     launch/

ros_gz_sim_demos/README.md

@@ -14,17 +14,12 @@ There's a convenient launch file, try for example:
 
 Publishes fluid pressure readings.
 
-    ros2 launch ros_gz_sim_demos air_pressure.launch.py
+    ros2 launch ros_gz_sim_demos air_pressure.launch.xml
 
-This demo also shows the use of custom QoS parameters. The sensor data is
-published as as "best-effort", so trying to subscribe to "reliable" data won't
-work. See the difference between:
+You can subscribe to receive the data with:
 
-    ros2 topic echo /air_pressure --qos-reliability best_effort
+    ros2 topic echo /air_pressure
 
-And
-
-    ros2 topic echo /air_pressure --qos-reliability reliable
 
 ![](images/air_pressure_demo.png)
 

ros_gz_sim_demos/config/air_pressure.yaml

@@ -0,0 +1,9 @@
+# Air pressure bridge configuration.
+- ros_topic_name: "air_pressure"
+  gz_topic_name: "air_pressure"
+  ros_type_name: "sensor_msgs/msg/FluidPressure"
+  gz_type_name: "gz.msgs.FluidPressure"
+  subscriber_queue: 5
+  publisher_queue: 6
+  lazy: false
+  direction: GZ_TO_ROS

ros_gz_sim_demos/launch/air_pressure.launch.xml

@@ -0,0 +1,6 @@
+<launch>
+  <gz_server world_sdf_file="sensors.sdf" use_composition="True" create_own_container="True" />
+  <ros_gz_bridge bridge_name="ros_gz_bridge" config_file="$(find-pkg-share ros_gz_sim_demos)/config/air_pressure.yaml" use_composition="True" />
+  <node pkg="rqt_topic" exec="rqt_topic"/>
+  <executable cmd="gz sim -g"/>
+</launch>