First example
#############

.. contents:: Table of Contents
   :depth: 2
   :local:

This tutorial teaches you how to run the first QRB ROS application.
It is intended for users who want to quickly run the camera on the board 
and get ready to use Rviz on an Ubuntu PC on the same LAN to see the real-time 
output of the camera.

Prerequisites
-------------

- Set up your environment. See :doc:`/getting_started/environment_setup`.

- Set up QIRP SDK.

Running camera
--------------

Download Code
^^^^^^^^^^^^^

1. Create a path to store the code on the Host PC.

2. Run the following commands to clone the code repository in this path.

.. code-block:: bash

    git clone https://github.com/quic-qrb-ros/lib_mem_dmabuf.git
    git clone https://github.com/quic-qrb-ros/qrb_ros_transport.git
    git clone https://github.com/quic-qrb-ros/qrb_ros_camera.git
    git clone https://github.com/quic-qrb-ros/qrb_ros_colorspace_convert.git

Build
^^^^^

Ensure that you have set up the QIRP SDK environment before building the code.

Then, you can use the following commands to build the code in QIRP SDK.

.. code-block:: bash

    export AMENT_PREFIX_PATH="${OECORE_TARGET_SYSROOT}/usr;${OECORE_NATIVE_SYSROOT}/usr"
    export PYTHONPATH=${PYTHONPATH}:${OECORE_TARGET_SYSROOT}/usr/lib/python3.10/site-packages

    colcon build --merge-install --cmake-args \
      -DPython3_ROOT_DIR=${OECORE_TARGET_SYSROOT}/usr \
      -DPython3_NumPy_INCLUDE_DIR=${OECORE_TARGET_SYSROOT}/usr/lib/python3.10/site-packages/numpy/core/include \
      -DSYSROOT_LIBDIR=${OECORE_TARGET_SYSROOT}/usr/lib \
      -DSYSROOT_INCDIR=${OECORE_TARGET_SYSROOT}/usr/include \
      -DPYTHON_SOABI=cpython-310-aarch64-linux-gnu -DCMAKE_STAGING_PREFIX=$(pwd)/install \
      -DCMAKE_PREFIX_PATH=$(pwd)/install/share \
      -DBUILD_TESTING=OFF

Push and install
^^^^^^^^^^^^^^^^

Run these commands to push and install the output SDK on the device.

.. code-block:: bash

    cd install
    tar czvf qrb_ros_example.tar.gz lib share
    scp qrb_ros_example.tar.gz root@[ip-addr]:/opt/
    ssh root@[ip-addr]
    (ssh) tar -zxf /opt/qrb_ros_example.tar.gz -C /opt/qcom/qirp-sdk/usr/

Run
^^^

Firstly, we need to create ``launch.py`` file that looks like:

.. code-block:: python

    import launch
    import os
    from ament_index_python.packages import get_package_share_directory
    from launch_ros.actions import ComposableNodeContainer
    from launch_ros.actions import Node
    from launch_ros.descriptions import ComposableNode

    def generate_launch_description():
        camera_info_config_file_path = os.path.join(
            get_package_share_directory('qrb_ros_camera'),
            'config', 'camera_info_imx577.yaml'
        )
        camera_info_path = camera_info_config_file_path
        print(camera_info_path)
        """Generate launch description with multiple components."""
        container = ComposableNodeContainer(
            name='my_container',
            namespace='',
            package='rclcpp_components',
            executable='component_container',
            composable_node_descriptions=[
                ComposableNode(
                    package='qrb_ros_camera',
                    plugin='qrb_ros::camera::CameraNode',
                    name='camera_node',
                    remappings=[('/image', '/image_raw')],
                    parameters=[{
                        'camera_info_path': camera_info_path,
                        'fps': 30,
                        'width': 1920,
                        'height': 1080,
                        'cameraId': 0,
                        'publish_latency_type': 1,
                    }]
                ),
                ComposableNode(
                    package='qrb_ros_colorspace_convert',
                    plugin='qrb_ros::colorspace_convert::ColorspaceConvertNode',
                    parameters=[{
                        'conversion_type': "nv12_to_rgb8",
                        'latency_fps_test': False,
                    }],
                    extra_arguments=[{'use_intra_process_comms': True, 'log_level': 'INFO'}],
                )
            ],
            output='screen',
        )

        return launch.LaunchDescription([container,
            Node(
                package='image_transport',
                executable='republish',
                output='screen',
                name='republish_node',
                arguments=[
                    'raw',  # Input
                    'compressed',  # Output
                ], 
                remappings=[
                    ('in', '/image'),
                    ('out/compressed', '/image_compressed'),
                ]
            ),
        ])


Secondly, we need to push this file to device.

.. code-block:: bash

    scp launch.py root@[ip-addr]:/opt/

Thirdly, we will use these cmd to run it on the device.

.. code-block:: bash

    ssh root@[ip-addr]
    (ssh) export XDG_RUNTIME_DIR=/dev/socket/weston/
    (ssh) export WAYLAND_DISPLAY=wayland-1
    (ssh) export HOME=/opt
    (ssh) source /opt/qcom/qirp-sdk/qirp-setup.sh
    (ssh) export ROS_DOMAIN_ID=1
    (ssh) source /usr/bin/ros_setup.bash
    (ssh) ros2 launch /opt/launch.py

Get the realtime image in Ubuntu PC
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

**Prerequisites**

- Set up an Ubuntu PC to be on the same LAN as the device.
- Install ROS2 Desktop on the Ubuntu PC following steps in `Install ROS <https://docs.ros.org/en/rolling/Installation/Ubuntu-Install-Debians.html>`_.

1. Use these commands in the first terminal to decompress the image.

    .. code-block:: bash

        source /opt/ros/<ros-version>/setup.sh
        export ROS_DOMAIN_ID=1
        ros2 run image_transport republish compressed raw --ros-args -r in/compressed:=/image_compressed -r out:=/image_repub

2. You can obtain real-time images from the ``image_repub`` topic in Rviz2.