Differences

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--- getting_started:tutorials:hal4 [2023/02/26 19:22] – [Using ROS1] ursgraf
+++ getting_started:tutorials:hal4 [2023/02/27 14:02] (current) – [Subscribing] ursgraf
@@ Line 18: / Line 18: @@
   * /test/state       (of type boolean)
-Use the same tools as in [[getting_started:tutorials:systemros1|]] to show nodes, topics and messages. The output on ''/test/state'' reflects what is input on ''/rosNodeTalker/state''. As long as this topic is not written to, the published state will not change, see below.
+Use the same tools as in [[getting_started:tutorials:systemros1#using_ros1|Control System Talking to ROS]] to show nodes, topics and messages. The output on ''/test/state'' reflects what is input on ''/rosNodeTalker/state''. As long as this topic is not written to, the published state will not change, see below.
 ==== Subscribing ====
@@ Line 37: / Line 37: @@
 In the EEROS library you will find a directory with examples. For this example see [[https://github.com/eeros-project/eeros-framework/blob/master/examples/ros2/RosTest2.cpp|RosTest2.cpp]].
-Open a shell and run ''roscore''. Open another shell in the build directory of your EEROS library and run
+Open a shell in the build directory of your EEROS library. This examples with ROS will only be present in your build directory if ROS2 was installed before building EEROS with ''-DUSE_ROS2=TRUE'' set, see [[getting_started:ros_prep|Preparations and Building]].
+If you work on a target make sure to setup the environment as given in [[getting_started:ros_run|]].
+Open a shell in the build directory of your EEROS library and run
 <code>
 $ sudo -E ./examples/ros/rosTest2 -c RosTest2Config.json
 </code>
+==== Publishing ====
+This example runs your EEROS application as a ROS node under the name ///eerosNode//. It publishes two topics
+  * /test/val         (of type double)
+  * /test/state       (of type boolean)
+Use the same tools as in [[getting_started:tutorials:systemros1#using_ros2|Control System Talking to ROS]] to show nodes, topics and messages. The output on ''/test/state'' reflects what is input on ''/rosNodeTalker/state''. As long as this topic is not written to, the published state will not change, see below.
+==== Subscribing ====
+Open another shell in the build directory of your EEROS library and run ''rosNodeTalker''. This is not a EEROS program but simply starts a ROS node which publishes a couple of test topics. As soon as ''rosNodeTalker'' runs, your example application will receive the two topics
+  * /rosNodeTalker/val    (of type double)
+  * /rosNodeTalker/state  (of type boolean)
+and logs its transported message values into the console. Use
+<code>
+$ rqt
+</code>
+to show a graph with all involved nodes together with their topics or to plot messages.