Tutorial: Teleoperate the Robot with a Joystick
===============================================

This demo will enable you to remote control the robot with a joystick.
Additionally, you will be able to visualize the outputs of the various sensors on
the robot with Foxglove.

For this tutorial, it is assumed that you have successfully setup your Nova Carter
robot using the setup instructions :doc:`here </robots/nova_carter/getting_started>` and
you are familiar with the Isaac ROS development environment.

Instructions
------------

1. SSH into the robot (:ref:`instructions<nova-carter-ssh-setup>`).

2. Make sure you have successfully connected the PS5 joystick to the robot
   (:ref:`instructions<nova-carter-joystick-setup>`).

3. Build/install the required packages:

.. run_ros_app::
    :repo_setup: <nova-carter-dev-setup>
    :repo: nova_carter
    :image: isaac/nova_carter_bringup:release_3.1-aarch64
    :package: nova_carter_bringup
    :app: teleop.launch.py
    :skip_packages: isaac_ros_ess_models_install:isaac_ros_peoplesemseg_models_install

4. You are now able to remote control the robot with the gamepad. You can use
   the left joystick to control the linear velocity and the right joystick to
   control the angular velocity of the robot. Please note that you have to press
   ``L1`` to enable the remote control. You can enable turbo mode by pressing
   ``R1``.

   Follow the next steps to additionally visualize the sensor outputs in Foxglove.

.. figure::
    :ir_lfs:`<resources/isaac_ros_docs/robots/nova_carter/joystick_controls.png>`
    :width: 800px
    :alt: Foxglove viz with joystick controls
    :align: center


Visualizing the Outputs
-----------------------

1. Make sure you complete :ref:`visualization-setup-carter`.

2. Open the Foxglove studio on your remote machine. In Foxglove,
   open the ``nova_carter_teleop.json`` layout file downloaded in the previous step.

3. Validate that you can see a visualization of the `Nova Carter` robot, an
   image of the front stereo camera and the scan lines of the front and back 2D
   lidar scanners. You should expect a visualization similar to the following:

.. figure::
    :ir_lfs:`<resources/isaac_ros_docs/robots/nova_carter/foxglove_teleop.png>`
    :width: 800px
    :alt: Foxglove visualization of the teleop outputs.
    :align: center

You can also visualize different sensors by enabling them in the left-hand panel.

.. note::

    This example will stream the camera images in their full resolution to
    Foxglove. This requires a substantial amount of bandwidth and is only done
    here for exemplary purposes. Most likely the image stream will be fairly
    choppy due to the large bandwidth. For a better visualization experience, we
    recommend only visualizing resized images or h264 streams.

.. note::

    Streaming higher bandwidth data to Foxglove causes higher latency. You can
    choose an appropriate value for the
    `send_buffer_limit <https://github.com/foxglove/ros-foxglove-bridge#configuration>`__
    parameter in Foxglove bridge to control latency vs. high bandwidth data visualization.

.. note::

    The fisheye cameras use the ``equidistant`` distortion model which is not
    yet supported in Foxglove. For this reason, it is not possible to visualize a
    fisheye camera in the 3D panel in Foxglove. You can however add an
    additional `Image` panel and use this to visualize the fisheye camera. In
    the `Image` panel's settings set `Topic` to the fisheye camera's image
    topic and set `Calibration` to ``None``.


Enabling Different Sensors
--------------------------

Per default, the launch file ``teleop.launch.py`` will enable the Segway
base, the front, left and right stereo cameras, the front and back 2D lidars and
the 3D lidar. You can however pass additional launch arguments to enable
different sensors.

To see all available launch arguments run

.. code:: bash

    ros2 launch nova_carter_bringup teleop.launch.py --show-args

To enable all sensors use the following launch command

.. code:: bash

    ros2 launch nova_carter_bringup teleop.launch.py \
        enable_3d_lidar:=True \
        enabled_2d_lidars:=front_2d_lidar,back_2d_lidar \
        enabled_stereo_cameras:=front_stereo_camera,back_stereo_camera,left_stereo_camera,right_stereo_camera \
        enabled_fisheye_cameras:=front_fisheye_camera,back_fisheye_camera,left_fisheye_camera,right_fisheye_camera

To disable all sensors and only run the Segway base use the following launch command

.. code:: bash

    ros2 launch nova_carter_bringup teleop.launch.py \
        enable_3d_lidar:=False \
        enabled_2d_lidars:=none \
        enabled_stereo_cameras:=none \
        enabled_fisheye_cameras:=none

You may also change the launch arguments to selectively dis-/enable sensors.