.. _examples:

ROS-Aseba: examples
===================

Setup
-----

To reproduce a multi-robot network (two Thymios with id 14031 and 21181, and two e-pucks with id 1 and 2), launch `Aseba Playground <http://wiki.thymio.org/en:asebaplayground>`_

.. code-block:: console

  asebaplayground

and open the world at ``ros-aseba/asebaros_examples/launch/simulation/multirobot.playground``

.. code-block:: xml

   <!DOCTYPE aseba-playground>
   <aseba-playground>
   	<author name="Jerome Guzzi" email="jerome at idsia dot ch" />
   	<description lang="en">A simple multi-robot playground to experiment with asebaros without physical robots.</description>
   	<color name="wall" r="0.9" g="0.9" b="0.9" />
   	<world w="100" h="100" color="wall"/>
   	<robot type="thymio2" x="45" y="15" port="33334" name="Thymio A" nodeId="1" />
   	<robot type="thymio2" x="45" y="45" port="33335" name="Thymio B" nodeId="1"/>
   	<robot type="e-puck" x="15" y="15" port="33336" name="E-Puck A" nodeId="1" />
   	<robot type="e-puck" x="15" y="45" port="33337" name="E-Puck B" nodeId="1" />
   </aseba-playground>

Use `Aseba Switch <http://wiki.thymio.org/en:asebaswitchremap>`_ to make the robots join the same network at port 33333.

.. code-block:: console

  asebaswitch "tcp:host=localhost\;port=33334\;remapLocal=21181\;remapTarget=1" "tcp:host=localhost\;port=33335\;remapLocal=14031\;remapTarget=1" "tcp:host=localhost\;port=33336\;remapLocal=1\;remapTarget=1" "tcp:host=localhost\;port=33337\;remapLocal=2\;remapTarget=1" -p 33333

With this setup ``DEVICE="tcp:host=localhost;port=33333"``.


To execute any ROS command, you have first to source the ROS setup script

.. tabs::

   .. code-tab:: bash Linux or macOS

      source <WORKSPACE>/install/setup.bash

   .. code-tab:: shell Windows

      C:<WORKSPACE>\install\setup.bat

.. note::
  The examples below works with any other Aseba network, and in particular with real robots too.
  In this case, just change the ids and add ``device:=<DEVICE>`` to the ROS launch arguments
  (e.g., ``device:="ser:name=Thymio"`` to connect a Thymio).

All nodes
----------

The following launch files configure ``asebaros`` to connect to all nodes at Dashel target ``device``.
Each node will receive a ROS namespace ``"node_{id}"``. No script will be automatically loaded into the nodes.

.. tabs::

   .. code-tab:: xml ROS1

      <launch>

        <arg name="device" default="tcp:host=localhost;port=33333"/>
        <arg name="port" value="44444"/>

        <node name="asebaros" pkg="asebaros" type="asebaros" output="screen">
          <param name="port" value="$(arg port)"/>
          <param name="shutdown_on_unconnect" value="false"/>
          <param name="highest_acceptable_protocol_version" value="20"/>
          <rosparam param="targets" subst_value="true">
            ["$(arg device)",]
          </rosparam>
          <rosparam param="nodes">
            any:
              accept: true
              prefix: node_
          </rosparam>
        </node>
      </launch>


   .. code-tab:: xml ROS2

      <launch>

        <arg name="device" default="tcp:host=localhost;port=33333"/>
        <let name="port" value="44444"/>

        <node pkg="asebaros" exec="asebaros" args="--log-level info" output="screen">
          <param name="port" value="$(var port)"/>
          <param name="shutdown_on_unconnect" value="false"/>
          <param name="highest_acceptable_protocol_version" value="20"/>
          <param name="targets" value="$(var device)" value-sep=","/>
          <param name="nodes">
            <param name="any">
              <param name="accept" value="true"/>
              <param name="prefix" value="node_"/>
            </param>
          </param>
        </node>
      </launch>


Launch it with

.. tabs::

   .. code-tab:: console ROS1

      roslaunch asebaros_examples all_nodes.launch

   .. code-tab:: console ROS2

      ros2 launch asebaros_examples all_nodes.launch

Inspect the system using services:

1. Get the list of nodes

.. tabs::

   .. code-tab:: console ROS1

      rosservice call /aseba/get_nodes asebaros_msgs/GetNodeList '{}'


   .. code-tab:: console ROS2

      ros2 service call /aseba/get_nodes asebaros_msgs/GetNodeList '{}'

2. Get the description of one of the nodes

.. tabs::

   .. code-tab:: console ROS1

      rosservice call /node_14031/aseba/get_description asebaros_msgs/GetDescription '{}'


   .. code-tab:: console ROS2

      ros2 service call /node_14031/aseba/get_description asebaros_msgs/GetDescription '{}'

3. Get the value of a variable

.. tabs::

   .. code-tab:: console ROS1

      rosservice call /node_14031/aseba/get_variable asebaros_msgs/GetVariable "{variable: prox.horizontal}"


   .. code-tab:: console ROS2

      ros2 service call /node_14031/aseba/get_variable asebaros_msgs/GetVariable "{variable: prox.horizontal}"


4. Set the value of a variable

.. tabs::

   .. code-tab:: console ROS1

      rosservice call /node_14031/aseba/set_variable asebaros_msgs/SetVariable "{variable: motor.left.target, data: [100]}"

   .. code-tab:: console ROS2

      ros2 service call /node_14031/aseba/set_variable asebaros_msgs/SetVariable "{variable: motor.left.target, data: [100]}"


A single node
-------------

The following launch files configure ``asebaros`` to connect to just the first Thymio
(i.e., the first Aseba node with ``name=="thymio-II"``)

.. tabs::

   .. code-tab:: xml ROS1

      <launch>

        <arg name="device" default="tcp:host=localhost;port=33333"/>
        <arg name="port" value="44444"/>

        <node name="asebaros" pkg="asebaros" type="asebaros" output="screen">
          <param name="port" value="$(arg port)"/>
          <param name="reload_script_on_reconnect" value="true"/>
          <param name="set_id_variable" value="false"/>
          <param name="shutdown_on_unconnect" value="false"/>
          <param name="highest_acceptable_protocol_version" value="20"/>
          <rosparam param="targets" subst_value="true">
            ["$(arg device)",]
          </rosparam>
          <rosparam param="nodes">
            others:
              accept: false
            thymio:
              name: thymio-II
              id_variable: _id
              accept: true
              include_id_in_events: false
              maximal_number: 1
          </rosparam>
          <rosparam param="script" subst_value="true">
            path: $(find asebaros_examples)/launch/single_node.aesl
            constants:
              MY_CONSTANT: 3
          </rosparam>
        </node>
      </launch>


   .. code-tab:: xml ROS2

      <launch>

        <arg name="device" default="tcp:host=localhost;port=33333"/>
        <let name="port" value="44444"/>

        <node pkg="asebaros" exec="asebaros" args="--log-level info" output="screen">
          <param name="port" value="$(var port)"/>
          <param name="reload_script_on_reconnect" value="true"/>
          <param name="set_id_variable" value="false"/>
          <param name="shutdown_on_unconnect" value="false"/>
          <param name="highest_acceptable_protocol_version" value="20"/>
          <param name="targets" value="$(var device)" value-sep=","/>
          <param name="nodes">
            <param name="others">
              <param name="accept" value="false"/>
            </param>
            <param name="thymio">
              <param name="type" value="thymio-II"/>
              <param name="id_variable" value="_id"/>
              <param name="accept" value="true"/>
              <param name="include_id_in_events" value="false"/>
              <param name="maximal_number" value="1"/>
            </param>
          </param>
          <param name="script">
            <param name="path" value="$(find-pkg-share asebaros_examples)/launch/single_node.aesl"/>
            <param name="constants">
              <param name="MY_CONSTANT" value="3"/>
            </param>
          </param>
        </node>
      </launch>

The node will receive an empty ROS namespace and a script will be automatically loaded into the node.
The script has a single constant ``MY_CONSTANT``, which the launch file sets to ``3``, and two events: ``ping`` and ``pong``.

  .. code-block:: xml

     <!DOCTYPE aesl-source>
     <network>

       <!--list of global events-->
       <event size="3" name="ping"/>
       <event size="3" name="pong"/>

       <!--list of constants-->
       <constant value="0" name="MY_CONSTANT"/>

       <!--show keywords state-->
       <keywords flag="true"/>

       <!--node thymio-II-->
       <node name="thymio-II">
         var value[3] = [MY_CONSTANT, MY_CONSTANT, MY_CONSTANT]
         emit pong value
         onevent ping
         value = event.args[0:2]
         emit pong value
       </node>

     </network>

The events are used to make the robot "pong" back the values (an array of length 3) sent with the ping.
Launch it with

.. tabs::

   .. code-tab:: console ROS1

      roslaunch asebaros_examples single_node.launch


   .. code-tab:: console ROS2

      ros2 launch asebaros_examples single_node.launch

In a new tab send a ping each second

.. tabs::

   .. code-tab:: console ROS1

      rostopic pub -r 1 /aseba/events/ping asebaros_msgs/Event '{data:  [1, 2, 3]}'


   .. code-tab:: console ROS2

      ros2 topic pub -r 1 /aseba/events/ping asebaros_msgs/Event '{data:  [1, 2, 3]}'

and in another one, listen for pongs

.. tabs::

   .. code-tab:: console ROS1

      rostopic echo /aseba/events/pong


   .. code-tab:: console ROS2

      ros2 topic echo /aseba/events/pong


Twin nodes
----------

In this case, we want to connect to *all* nodes and load the same script.
Each node will receive a namespace ``"node_{id}"``.

.. tabs::

   .. code-tab:: xml ROS1

      <launch>

        <arg name="device" default="tcp:host=localhost;port=33333"/>
        <arg name="port" value="44444"/>

        <node name="asebaros" pkg="asebaros" type="asebaros" output="screen">
          <param name="port" value="$(arg port)"/>
          <param name="reload_script_on_reconnect" value="true"/>
          <param name="set_id_variable" value="true"/>
          <param name="shutdown_on_unconnect" value="false"/>
          <param name="highest_acceptable_protocol_version" value="20"/>
          <rosparam param="targets" subst_value="true">
            ["$(arg device)",]
          </rosparam>
          <rosparam param="nodes">
            any:
              prefix: node_
              accept: true
              include_id_in_events: true
            thymio:
              name: thymio-II
              id_variable: _id
            epuck:
              name: e-puck0
              id_variable: id
          </rosparam>
          <rosparam param="script" subst_value="true">
            path: $(find asebaros_examples)/launch/twin_nodes.aesl
            constants:
              MY_CONSTANT: 3
          </rosparam>
        </node>
      </launch>

   .. code-tab:: xml ROS2

      <launch>

        <arg name="device" default="tcp:host=localhost;port=33333"/>
        <let name="port" value="44444"/>

        <node pkg="asebaros" exec="asebaros" args="--log-level info" output="screen">
          <param name="port" value="$(var port)"/>
          <param name="reload_script_on_reconnect" value="true"/>
          <param name="set_id_variable" value="true"/>
          <param name="shutdown_on_unconnect" value="false"/>
          <param name="highest_acceptable_protocol_version" value="20"/>
          <param name="targets" value="$(var device)" value-sep=","/>
          <param name="nodes">
            <param name="any">
              <param name="prefix" value="node_"/>
              <param name="accept" value="true"/>
              <param name="include_id_in_events" value="true"/>
            </param>
            <param name="thymio">
              <param name="name" value="thymio-II"/>
              <param name="id_variable" value="_id"/>
            </param>
            <param name="epuck">
              <param name="name" value="e-puck0"/>
              <param name="id_variable" value="id"/>
            </param>
          </param>
          <param name="script">
            <param name="path" value="$(find-pkg-share asebaros_examples)/launch/twin_nodes.aesl"/>
            <param name="constants">
              <param name="MY_CONSTANT" value="3"/>
            </param>
          </param>
        </node>
      </launch>

Because the id of the target node is included in the event ``ping`` (``include_id_in_events=true``),
the script can check if the event is addressed at the current node,
and *only in this case* "pong" back.

.. code-block:: xml

   <!DOCTYPE aesl-source>
   <network>

     <!--list of global events-->
     <event size="4" name="ping"/>
     <event size="3" name="pong"/>

     <!--list of constants-->
     <constant value="0" name="MY_CONSTANT"/>

     <!--show keywords state-->
     <keywords flag="true"/>

     <!--node thymio-II-->
     <node name="thymio-II">
       var value[3] = [MY_CONSTANT, MY_CONSTANT, MY_CONSTANT]
       emit pong value
       onevent ping
       if (event.args[0] == _id) then
         value = event.args[1:3]
         emit pong value
       end
     </node>

   </network>

Launch ROS with

.. tabs::

   .. code-tab:: console ROS1

      roslaunch asebaros_examples twin_nodes.launch


   .. code-tab:: console ROS2

      ros2 launch asebaros_examples twin_nodes.launch

In a new tab send pings each second to a specific robot

.. tabs::

  .. code-tab:: console ROS1

     rostopic pub -r 1 /node_14031/aseba/events/ping asebaros_msgs/Event '{data:  [1, 2, 3]}'


  .. code-tab:: console ROS2

     ros2 topic pub -r 1 /node_14031/aseba/events/ping asebaros_msgs/Event '{data:  [1, 2, 3]}'

and in another one, listen for pongs from different robots

.. tabs::

   .. code-tab:: console ROS1

      ros2 topic echo /node_14031/aseba/events/pong
      ros2 topic echo /node_21181/aseba/events/pong


   .. code-tab:: console ROS2

      ros2 topic echo /node_14031/aseba/events/pong
      ros2 topic echo /node_21181/aseba/events/pong


Two nodes
---------

In this case, we want to connect to two nodes of different types.
As the different nodes uses different [incoming] events, we don't need to include the node id in the event.

.. tabs::

   .. code-tab:: xml ROS1

      <launch>

        <arg name="device" default="tcp:host=localhost;port=33333"/>
        <arg name="port" value="44444"/>

        <node name="asebaros" pkg="asebaros" type="asebaros" output="screen">
          <param name="port" value="$(arg port)"/>
          <param name="reload_script_on_reconnect" value="true"/>
          <param name="set_id_variable" value="false"/>
          <param name="shutdown_on_unconnect" value="false"/>
          <param name="highest_acceptable_protocol_version" value="20"/>
          <rosparam param="targets" subst_value="true">
            ["$(arg device)",]
          </rosparam>
          <rosparam param="nodes">
            others:
              accept: false
            thymio:
              name: thymio-II
              id_variable: _id
              accept: true
              namespace: thymio
              include_id_in_events: false
              maximal_number: 1
            epuck:
              name: e-puck0
              id_variable: id
              accept: true
              namespace: epuck
              include_id_in_events: false
              maximal_number: 1
          </rosparam>
          <rosparam param="script" subst_value="true">
            path: $(find asebaros_examples)/launch/two_nodes.aesl
            constants:
              MY_CONSTANT_THYMIO: 3
              MY_CONSTANT_EPUCK: 333
          </rosparam>
        </node>
      </launch>

   .. code-tab:: xml ROS2

      <launch>

        <arg name="device" default="tcp:host=localhost;port=33333"/>
        <let name="port" value="44444"/>

        <node pkg="asebaros" exec="asebaros" args="--log-level info" output="screen">
          <param name="port" value="$(var port)"/>
          <param name="reload_script_on_reconnect" value="true"/>
          <param name="set_id_variable" value="false"/>
          <param name="shutdown_on_unconnect" value="false"/>
          <param name="highest_acceptable_protocol_version" value="20"/>
          <param name="targets" value="$(var device)" value-sep=","/>
          <param name="nodes">
            <param name="thymio">
              <param name="name" value="thymio-II"/>
              <param name="namespace" value="thymio"/>
              <param name="accept" value="true"/>
              <param name="id_variable" value="_id"/>
              <param name="maximal_number" value="1"/>
              <param name="include_id_in_events" value="false"/>
            </param>
            <param name="epuck">
              <param name="name" value="e-puck0"/>
              <param name="namespace" value="epuck"/>
              <param name="accept" value="true"/>
              <param name="id_variable" value="id"/>
              <param name="maximal_number" value="1"/>
              <param name="include_id_in_events" value="false"/>
            </param>
          </param>
          <param name="script">
            <param name="path" value="$(find-pkg-share asebaros_examples)/launch/two_nodes.aesl"/>
            <param name="constants">
              <param name="MY_CONSTANT_THYMIO" value="3"/>
              <param name="MY_CONSTANT_EPUCK" value="333"/>
            </param>
          </param>
        </node>
      </launch>


.. code-block:: xml

   <!DOCTYPE aesl-source>
   <network>

     <!--list of global events-->
     <event size="3" name="ping_thymio"/>
     <event size="3" name="ping_epuck"/>
     <event size="3" name="pong"/>

     <!--list of constants-->
     <constant value="0" name="MY_CONSTANT_THYMIO"/>
     <constant value="0" name="MY_CONSTANT_EPUCK"/>

     <!--show keywords state-->
     <keywords flag="true"/>

     <!--node thymio-II-->
     <node name="thymio-II">
       var value[3] = [MY_CONSTANT_THYMIO, MY_CONSTANT_THYMIO, MY_CONSTANT_THYMIO]
       emit pong value
       onevent ping_thymio
       value = event.args[0:2]
       emit pong value
     </node>

     <!--node e-puck0-->
     <node name="e-puck0">
       var value[3] = [MY_CONSTANT_EPUCK, MY_CONSTANT_EPUCK, MY_CONSTANT_EPUCK]
       emit pong value
       onevent ping_epuck
       value = args[0:2]
       emit pong value
     </node>

   </network>

Launch ROS with

.. tabs::

   .. code-tab:: console ROS1

      roslaunch asebaros_examples two_nodes.launch


   .. code-tab:: console ROS2

      ros2 launch asebaros_examples two_nodes.launch

In a new tab send pings each second to a specific robot

.. tabs::

  .. code-tab:: console ROS1

     rostopic pub -r 1 /epuck/aseba/events/ping_epuck asebaros_msgs/Event '{data:  [1, 2, 3]}'


  .. code-tab:: console ROS2

     ros2 topic pub -r 1 /epuck/aseba/events/ping_epuck asebaros_msgs/Event '{data:  [1, 2, 3]}'

and in another one, listen for pongs

.. tabs::

   .. code-tab:: console ROS1

      rostopic echo /epuck/aseba/events/pong


   .. code-tab:: console ROS2

      ros2 topic echo /epuck/aseba/events/pong



A single Thymio
---------------

The following launch files configure asebaros to connect to just the first Thymio
(i.e., the first Aseba node with ``name=="thymio-II"``), and a script will be automatically loaded into the node.

.. tabs::

   .. code-tab:: xml ROS1

      <launch>

        <arg name="device" default="tcp:host=localhost;port=33333"/>
        <arg name="port" value="44444"/>

        <node name="asebaros" pkg="asebaros" type="asebaros" output="screen">
          <param name="port" value="$(arg port)"/>
          <param name="reload_script_on_reconnect" value="true"/>
          <param name="set_id_variable" value="false"/>
          <param name="shutdown_on_unconnect" value="false"/>
          <param name="highest_acceptable_protocol_version" value="20"/>
          <rosparam param="targets" subst_value="true">
            ["$(arg device)",]
          </rosparam>
          <rosparam param="nodes">
            others:
              accept: false
            thymio:
              type: thymio-II
              id_variable: _id
              accept: true
              name: thymio
              include_id_in_events: false
              maximal_number: 1
          </rosparam>
          <rosparam param="script" subst_value="true">
            path: $(find asebaros_examples)/launch/single_thymio.aesl
            constants:
              OBSTACLE_THRESHOLD: 2500
          </rosparam>
        </node>
      </launch>


   .. code-tab:: xml ROS2

      <launch>

        <arg name="device" default="tcp:host=localhost;port=33333"/>
        <let name="port" value="44444"/>

        <node pkg="asebaros" exec="asebaros" args="--log-level info" output="screen">
          <param name="port" value="$(var port)"/>
          <param name="reload_script_on_reconnect" value="true"/>
          <param name="set_id_variable" value="false"/>
          <param name="shutdown_on_unconnect" value="false"/>
          <param name="highest_acceptable_protocol_version" value="20"/>
          <param name="targets" value="$(var device)" value-sep=","/>
          <param name="nodes">
            <param name="thymio">
              <param name="type" value="thymio-II"/>
              <param name="id_variable" value="_id"/>
              <param name="accept" value="true"/>
              <param name="name" value="thymio"/>
              <param name="include_id_in_events" value="false"/>
              <param name="maximal_number" value="1"/>
            </param>
            <param name="others">
              <param name="accept" value="false"/>
            </param>
          </param>
          <param name="script">
            <param name="path" value="$(find-pkg-share asebaros_examples)/launch/single_thymio.aesl"/>
            <param name="constants">
              <param name="OBSTACLE_THRESHOLD" value="2500"/>
            </param>
          </param>
        </node>
      </launch>

This time, the node will receive a ROS namespace ``thymio`` and the script is specific for the Thymio.

  .. code-block:: xml

     <!DOCTYPE aesl-source>
     <network>

       <!--list of global events-->
       <event size="3" name="set_color"/>
       <event size="0" name="obstacle"/>

       <!--list of constants-->
       <constant value="2000" name="OBSTACLE_THRESHOLD"/>

       <!--show keywords state-->
       <keywords flag="true"/>

       <!--node thymio-II-->
       <node name="thymio-II">
         onevent prox
         if (prox.horizontal[2] > OBSTACLE_THRESHOLD) then
           call leds.buttons(32, 32, 32, 32)
           emit obstacle
         else
           call leds.buttons(0, 0, 0, 0)
         end
         onevent set_color
         call leds.top(event.args[0], event.args[1], event.args[2])
       </node>

     </network>

The constant ``OBSTACLE_THRESHOLD``  controls the onboard behavior that makes the Thymio turn on the button LED
to signal a close object. The ``obstacle`` event is used to notify ROS of an obstacle while the ``set_color`` event
is used by ROS to change the Thymio body color.

Launch ROS with

.. tabs::

   .. code-tab:: console ROS1

      roslaunch asebaros_examples single_thymio.launch


   .. code-tab:: console ROS2

      ros2 launch asebaros_examples single_thymio.launch


In a new tab set the body LED of the Thymio to cyan

.. tabs::

   .. code-tab:: console ROS1

      rostopic pub --once /thymio/aseba/events/set_color asebaros_msgs/Event '{data:  [0, 32, 32]}'


   .. code-tab:: console ROS2

      ros2 topic pub --once /thymio/aseba/events/set_color asebaros_msgs/Event '{data:  [0, 32, 32]}'

and in another one, listen for obstacles (move around the cyan robot)

.. tabs::

   .. code-tab:: console ROS1

      rostopic echo /thymio/aseba/events/obstacle


   .. code-tab:: console ROS2

      ros2 topic echo /thymio/aseba/events/obstacle


Twin Thymios
---------------

We want to connect to any Thymio in the network and load the same script. Each of them will get the namespace ``"thymio_{id}"``.

.. tabs::

   .. code-tab:: xml ROS1

      <launch>

        <arg name="device" default="tcp:host=localhost;port=33333"/>
        <arg name="port" value="44444"/>

        <node name="asebaros" pkg="asebaros" type="asebaros" output="screen">
          <param name="port" value="$(arg port)"/>
          <param name="reload_script_on_reconnect" value="true"/>
          <param name="set_id_variable" value="true"/>
          <param name="shutdown_on_unconnect" value="false"/>
          <param name="highest_acceptable_protocol_version" value="20"/>
          <rosparam param="targets" subst_value="true">
            ["$(arg device)",]
          </rosparam>
          <rosparam param="nodes">
            others:
              accept: false
            thymio:
              name: thymio-II
              id_variable: _id
              accept: true
              prefix: thymio_
              include_id_in_events: true
          </rosparam>
          <rosparam param="script" subst_value="true">
            path: $(find asebaros_examples)/launch/twin_thymios.aesl
            constants:
              OBSTACLE_THRESHOLD: 2500
          </rosparam>
        </node>
      </launch>



   .. code-tab:: xml ROS2

      <launch>

        <arg name="device" default="tcp:host=localhost;port=33333"/>
        <let name="port" value="44444"/>

        <node pkg="asebaros" exec="asebaros" args="--log-level info" output="screen">
          <param name="port" value="$(var port)"/>
          <param name="reload_script_on_reconnect" value="true"/>
          <param name="set_id_variable" value="true"/>
          <param name="shutdown_on_unconnect" value="false"/>
          <param name="highest_acceptable_protocol_version" value="20"/>
          <param name="targets" value="$(var device)" value-sep=","/>
          <param name="nodes">
            <param name="thymio">
              <param name="name" value="thymio-II"/>
              <param name="id_variable" value="_id"/>
              <param name="prefix" value="thymio_"/>
              <param name="accept" value="true"/>
              <param name="include_id_in_events" value="true"/>
            </param>
            <param name="others">
              <param name="accept" value="false"/>
            </param>
          </param>
          <param name="script">
            <param name="path" value="$(find-pkg-share asebaros_examples)/launch/twin_thymios.aesl"/>
            <param name="constants">
              <param name="OBSTACLE_THRESHOLD" value="2500"/>
            </param>
          </param>
        </node>
      </launch>

Because the paramer ``include_id_in_events`` is set to ``true``, ``asebaros`` will include the [target] robot id in the event ``set_color``.
The script checks that the command targets the current robot, else it ignores it.

  .. code-block:: xml

     <!DOCTYPE aesl-source>
     <network>

     <!--list of global events-->
     <event size="4" name="set_color"/>
     <event size="0" name="obstacle"/>

     <!--list of constants-->
     <constant value="2000" name="OBSTACLE_THRESHOLD"/>

     <!--show keywords state-->
     <keywords flag="true"/>

     <!--node thymio-II-->
     <node name="thymio-II">
       onevent prox
         if (prox.horizontal[2] > OBSTACLE_THRESHOLD) then
           call leds.buttons(32, 32, 32, 32)
           emit obstacle
         else
           call leds.buttons(0, 0, 0, 0)
         end
       onevent set_color
         if (event.args[0] == _id) then
           call leds.top(event.args[1], event.args[2], event.args[3])
         end
     </node>

     </network>

Launch ROS with

.. tabs::

   .. code-tab:: console ROS1

      roslaunch asebaros_examples twin_thymios.launch


   .. code-tab:: console ROS2

      ros2 launch asebaros_examples twin_thymios.launch


In a new tab set the body LED of Thymio to cyan and of the other to yellow

.. tabs::

   .. code-tab:: console ROS1

      rostopic pub --once /thymio_14031/aseba/events/set_color asebaros_msgs/Event '{data:  [32, 32, 0]}'
      rostopic pub --once /thymio_21181/aseba/events/set_color asebaros_msgs/Event '{data:  [0, 32, 32]}'


   .. code-tab:: console ROS2

      ros2 topic pub --once /thymio_14031/aseba/events/set_color asebaros_msgs/Event '{data:  [0, 32, 32]}'
      ros2 topic pub --once /thymio_21181/aseba/events/set_color asebaros_msgs/Event '{data:  [32, 32, 0]}'


Two Thymios
-----------

In this example, we want connect to two specific Thymio identified by id, assign them to predefined namespaces (Thymio 21181 to ``"red"`` and Thymio 14031 to ``"green"``), and automatically set their body LED color coherently.

.. tabs::

   .. code-tab:: xml ROS1

      <launch>

        <arg name="device" default="tcp:host=localhost;port=33333"/>
        <arg name="port" value="44444"/>

        <node name="asebaros" pkg="asebaros" type="asebaros" output="screen">
          <param name="port" value="$(arg port)"/>
          <param name="reload_script_on_reconnect" value="true"/>
          <param name="set_id_variable" value="true"/>
          <param name="shutdown_on_unconnect" value="false"/>
          <param name="highest_acceptable_protocol_version" value="20"/>
          <rosparam param="targets" subst_value="true">
            ["$(arg device)",]
          </rosparam>
          <rosparam param="nodes">
            others:
              accept: false
            thymio:
              name: thymio-II
              id_variable: _id
              accept: false
              include_id_in_events: false
            thymio_21181:
              id: 21181
              name: thymio-II
              accept: true
              namespace: red
            thymio_14031:
              id: 14031
              name: thymio-II
              accept: true
              namespace: green
          </rosparam>
          <rosparam param="script" subst_value="true">
            path: $(find asebaros_examples)/launch/two_thymios.aesl
          </rosparam>
        </node>
      </launch>

   .. code-tab:: xml ROS2

      <launch>

        <arg name="device" default="tcp:host=localhost;port=33333"/>
        <let name="port" value="44444"/>

        <node pkg="asebaros" exec="asebaros" args="--log-level info" output="screen">
          <param name="port" value="$(var port)"/>
          <param name="reload_script_on_reconnect" value="true"/>
          <param name="set_id_variable" value="true"/>
          <param name="shutdown_on_unconnect" value="false"/>
          <param name="highest_acceptable_protocol_version" value="20"/>
          <param name="targets" value="$(var device)" value-sep=","/>
          <param name="nodes">
            <param name="thymio">
              <param name="name" value="thymio-II"/>
              <param name="id_variable" value="_id"/>
              <param name="accept" value="false"/>
              <param name="include_id_in_events" value="false"/>
            </param>
            <param name="thymio_21181">
              <param name="name" value="thymio-II"/>
              <param name="accept" value="true"/>
              <param name="id" value="21181"/>
              <param name="namespace" value="red"/>
            </param>
            <param name="thymio_14031">
              <param name="name" value="thymio-II"/>
              <param name="accept" value="true"/>
              <param name="id" value="14031"/>
              <param name="namespace" value="green"/>
            </param>
            <param name="others">
              <param name="accept" value="false"/>
            </param>
          </param>
          <param name="script">
            <param name="path" value="$(find-pkg-share asebaros_examples)/launch/two_thymios.aesl"/>
          </param>
        </node>
      </launch>


Different code get uploaded to each of them: one will turn red, while the other green.

  .. code-block:: xml

     <!DOCTYPE aesl-source>
     <network>

     <!--list of global events-->

     <!--list of constants-->

     <!--show keywords state-->
     <keywords flag="true"/>

     <!--node thymio-II-->
     <node nodeId="21181" name="thymio-II">
       call leds.top(32, 0, 0)
     </node>
     <node nodeId="14031" name="thymio-II">
       call leds.top(0, 32, 0)
     </node>

     </network>


Launch ROS with

.. tabs::

   .. code-tab:: console ROS1

      roslaunch asebaros_examples two_thymios.launch


   .. code-tab:: console ROS2

      ros2 launch asebaros_examples two_thymios.launch


Check that the correct namespaces are being used

.. tabs::

   .. code-tab:: console ROS1

      rostopic list

   .. code-tab:: console ROS2

      ros2 topic list