Started wiki page about namespaces

pps_wiki/namespace_conventions.md

+# ROS Namespace Conventions
+
+## Environment Variables
+
+### ``ROS_NAMESPACE`` Environment Variable
+
+All computers part of the ``D-FaLL-System`` should have the environment variable ``ROS_NAMESPACE`` set to the value ``dfall``.
+
+You can check this from any terminal window with the command
+```
+echo $ROS_NAMESPACE
+```
+
+This environment vairable is set in the file:
+```
+pps_ws/src/d_fall_pps/launch/Config.sh
+```
+The environemnt variable is set by the following line in that file:
+```
+export ROS_NAMESPACE='dfall'
+```
+
+### ``DEFAULT_{AGENT,COORD}_ID`` Environment Variables
+
+The ``Config.sh`` also sets the environment variables for the default agent ID and the default coordinator ID, called ``DFALL_DEFAULT_AGENT_ID`` and ``DFALL_DEFAULT_COORD_ID``. These are set by the following line in the ``Config.sh`` file:
+```
+export DFALL_DEFAULT_AGENT_ID=$(cat /etc/dfall_default_agent_id)
+export DFALL_DEFAULT_COORD_ID=$(cat /etc/dfall_default_coord_id)
+```
+This is the only place in the whole ``D-FaLL-System`` where the files ``/etc/dfall_default_{agent,coord}_id`` are referred to.
+
+NOTE:
+- These files should never be access from within any code,<br>
+- To use these default ID's within any code, they should be added as parameters when launch the respective node,<br>
+- The launch files is the only place where the default ID environment variables should be used.<br>
+
+
+
+## Launching nodes
+
+To be filled in
\ No newline at end of file

pps_ws/src/d_fall_pps/launch/Agent.launch

 <launch>
 
 	<!-- INPUT ARGUMENT OF THE AGENT's ID -->
-	<arg name="agentid" default="$(optenv DFALL_DEFAULT_ID)" />
+	<arg name="agentID" default="$(optenv DFALL_DEFAULT_AGENT_ID)" />
 
-	<!-- Example of how to use the value in agentid -->
-    <!-- <param name="param" value="$(arg agentid)"/> -->
+	<!-- Example of how to use the value in agentID -->
+    <!-- <param name="param" value="$(arg agentID)"/> -->
 
-    <group ns="agent$(arg agentid)">
+    <group ns="agent$(arg agentID)">
 
 		<!-- CRAZY RADIO -->
 		<node
@@ -26,7 +26,7 @@
 			type   = "PPSClient"
 			>
 			<rosparam command="load" file="$(find d_fall_pps)/param/ClientConfig.yaml" />
-			<param name="agentID" value="$(arg agentid)" />
+			<param name="agentID" value="$(arg agentID)" />
 		</node>
 
 		<!-- SAFE CONTROLLER -->
@@ -55,7 +55,7 @@
 			type   = "ParameterService"
 			>
 			<param name="type"     type="str"  value="agent" />
-			<param name="agentID"  type="str"  value="$(arg agentid)" />
+			<param name="agentID"  type="str"  value="$(arg agentID)" />
 			<rosparam
 				command = "load"
 				file    = "$(find d_fall_pps)/param/SafeController.yaml"

pps_ws/src/d_fall_pps/launch/Config.sh

 export ROS_MASTER_URI=http://teacher:11311
 export ROS_IP=$(hostname -I | awk '{print $1;}')
-export DFALL_DEFAULT_ID=$(cat /etc/dfall_default_id)
+export DFALL_DEFAULT_AGENT_ID=$(cat /etc/dfall_default_agent_id)
+export DFALL_DEFAULT_COORD_ID=$(cat /etc/dfall_default_coord_id)
 export ROS_NAMESPACE='dfall'