Troubleshooting
===============

How do I Pair the Bluetooth Joystick with the Nova Carter Robot?
----------------------------------------------------------------

Refer to the :ref:`pairing the controller section<nova-carter-joystick-setup>`.

Jetson Won't Connect to the Monitor Unless Ethernet Is Connected
----------------------------------------------------------------

This is a known bug. We'd recommend that you have the Nova Carter robot
connected to Ethernet during the initial SW setup procedure in the
documentation.

Robot Does Not Move
-------------------

1. In a terminal inside the Docker container, run ``ros topic echo /cmd_vel``.

Ensure that when you press the buttons or move the joysticks, the values on the
topic change. If it does not show any data move to the next step.  2. If you can
see the expected values in the above command when pressing the joystick, check
if the horizontal indicator light next to the power button on the robot is
green. If it is not green, then the Segway ROS driver has gone into "locked
state".

You can fix this by running
`ros2 service call /reset_chassis std_srvs/srv/Empty {}`
in a new terminal that is attached to the Isaac ROS Docker container. The
Segway driver has to be running to reset the chassis. Restarting the teleop,
Nav2, or mapping launch files also resets the Segway driver.


``/cmd_vel`` Shows No Data when the Joystick Enable Button is Pressed
---------------------------------------------------------------------

1.  In a terminal inside the Docker container run ``ls /dev/input/js0``.  If the
    connection was successful it prints out ``/dev/input/js0``. If the connection
    was **not** successful the command prints out ``ls: cannot access
    '/dev/input/js0': No such file or directory``.  2. In a terminal inside the
    Docker container run ``ros topic echo /joy``. Ensure that when you press the
    buttons or move the joysticks, the values on the topic change.  3. Ensure your
    joystick is connected by following the joystick pairing steps in this document.


``ros2 topic hz`` Shows a Lower than Expected Value
----------------------------------------------------

.. note::

    ``ros2 topic hz`` is known to cause 100% CPU load for the first ~6 seconds
    after running the command. The frame rate measured during this period is
    inaccurate compared to when the command is not running. Use the ``--window``
    flag as shown below and wait for ~6 seconds to get a more accurate measurement.

.. note:: ``ros2 topic hz`` also triggers the type adaptation NITROS nodes.

1. Run the following command to get a list of all the topics:

.. code:: bash

    ros2 topic list

2. Run the ``ros2 topic hz`` command of the required topic:

.. code:: bash

    ros2 topic hz <topic_name> --window 30

``ros2 topic list`` on a remote system does not show all topics on robot
------------------------------------------------------------------------

.. note:: We use Cyclone DDS as our ROS 2 middleware interface

.. note::

    When using the below Cyclone DDS configuration file, replace
    ``your_network_interface``, ``robot_ip`` and ``remote_system_ip`` with
    appropriate values.

1. Check if your system allows multicast communication by following the steps in
   `this medium post <https://medium.com/@arshad.mehmood/setting-up-node-discovery-across-multiple-systems-in-ros2-infrastructure-a1a5c25f052f>`__

2. If it does not, disable multicast and set the peer IPs manually as shown in
   `this medium post <https://medium.com/@arshad.mehmood/setting-up-node-discovery-across-multiple-systems-in-ros2-infrastructure-a1a5c25f052f>`__.
   An example of the cyclone DDS config file is also given below:

.. code:: xml

    <CycloneDDS xmlns="https://cdds.io/config" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="https://cdds.io/config https://raw.githubusercontent.com/eclipse-cyclonedds/cyclonedds/master/etc/cyclonedds.xsd">
    <Domain id="any">
        <General>
            <Interfaces>
                <!-- Replace <your_network_interface> with the value corresponding to your setup. -->
                <NetworkInterface name="<your_network_interface_name>"  multicast="false" />
            </Interfaces>
            <AllowMulticast>false</AllowMulticast>
            <EnableMulticastLoopback>false</EnableMulticastLoopback>
        </General>

        <Discovery>
            <Peers>
                <!-- Replace <robot_ip> and <remote_system_ip> with the IP addresses corresponding to your setup. -->
                <Peer address="<robot_ip>"/>
                <Peer address="<remote_system_ip>"/>
            </Peers>
            <ParticipantIndex>auto</ParticipantIndex>
            <MaxAutoParticipantIndex>200</MaxAutoParticipantIndex>
        </Discovery>
    </Domain>
    </CycloneDDS>