Ros - ArchWiki

# Ros

From ArchWiki

ROS is an open-source, meta-operating system for your robot. It provides the services you would expect from an operating system, including hardware abstraction, low-level device control, implementation of commonly-used functionality, message-passing between processes, and package management.

## Installation Instructions

### Lunar

ROS Lunar is available in AUR packages and seems to be working quite nicely. The ros-lunar-desktop-fullAUR is complete and seems to have everything functional.

### Kinetic

Kinetic packages on the AUR are a work in progress. There are some issues regarding opencv3 that have not been fully resolved yet (installing ros-kinetic-opencv3AUR works, but is somewhat inefficient since it rebuilds opencv3). Currently, installing a metapackage such as ros-kinetic-ros-coreAUR or ros-kinetic-robotAUR should bring in all required dependencies (see [1] for the correct order, or use an AUR helper that fully resolves dependency trees).

Packages are being added on an as-needed basis. Please send package requests to <aur AT seangreenslade DOT com>, and post any issues with the current packages in their respective AUR comments section.

### Configure the build tool

## catkin_make

Note that catkin uses python2, and therefore catkin_make may fail unless it is explicitly pointed to the python2 install. To do so, add the following alias to your .bashrc (or equivalent):

    alias catkin_make="catkin_make -DPYTHON_EXECUTABLE=/usr/bin/python2 -DPYTHON_INCLUDE_DIR=/usr/include/python2.7 -DPYTHON_LIBRARY=/usr/lib/libpython2.7.so"

## catkin build

For configuring the systems using the `catkin build` environment, one have to configure the catkin workspace as usual and issue a

    catkin config -DPYTHON_EXECUTABLE\=/usr/bin/python2 -DPYTHON_INCLUDE_DIR=/usr/include/python2.7 -DPYTHON_LIBRARY=/usr/lib/libpython2.7.so"

Afterwards, use `catkin build` as normal. Please remember to reconfigure your catkin whenever you delete the configuration files (i.e. the `catkin_ws` directory)

## Rebuild when shared libraries are updated

When you update a library that ROS depends on (e.g. Boost), all packages that link to it must be rebuilt. Most AUR helpers will not detect this situation. The following script will generate a list of all packages that are linked to missing so files:

https://seangreenslade.com/h/snippets/ros-find-outofdate.py

(Note that the script requires pyalpm to be installed.)

## Ros 2

### Building from source

Build instructions are available at https://github.com/ros2/ros2/wiki/Linux-Development-Setup.

Install build dependencies: wget, python, python-yaml, python-setuptools, git, cmake, asio, tinyxml, tinyxml2, eigen, libxaw, glu, qt5-base, opencv, python-vcstoolAUR, python-empyAUR.

Fetch the sources:

    $ mkdir -p ~/ros2_ws/src
    $ cd ~/ros2_ws
    $ wget https://raw.githubusercontent.com/ros2/ros2/release-latest/ros2.repos
    $ vcs-import src < ros2.repos

Presently some fixes are required:

    $ cd ~/ros2_ws/src/ros2/rviz/
    $ git remote add racko https://github.com/racko/rviz.git
    $ git fetch racko added_cmake_project_type fix_fallthrough fix_wrong_yaml_cpp
    $ git cherry-pick racko/added_cmake_project_type racko/fix_fallthrough racko/fix_wrong_yaml_cpp

Now you can build the workspace:

    $ cd ~/ros2_ws
    $ src/ament/ament_tools/scripts/ament.py build --symlink-install

Read https://github.com/ros2/ros1_bridge/blob/master/README.md#build-the-bridge-from-source regarding Ros 1 / Ros 2 interoperability.

### Usage Examples

First source the workspace:

    $ . ~/ros2_ws/install/local_setup.bash

Functionality comparable to `roscore`, `rosnode`, `rostopic`, `rosmsg`, `rospack`, `rosrun` and `rosservice` is available via `ros2`:

    $ ros2 -h
    usage: ros2 [-h] Call `ros2 <command> -h` for more detailed usage. ...

    ros2 is an extensible command-line tool for ROS 2.

    optional arguments:
      -h, --help            show this help message and exit

    Commands:
      daemon    Various daemon related sub-commands
      msg       Various msg related sub-commands
      node      Various node related sub-commands
      pkg       Various package related sub-commands
      run       Run a package specific executable
      security  Various security related sub-commands
      service   Various service related sub-commands
      srv       Various srv related sub-commands
      topic     Various topic related sub-commands

      Call `ros2 <command> -h` for more detailed usage.

A typical "Hello World" example starts with running a publisher node:

    $ ros2 topic pub /chatter 'std_msgs/String' "data: 'Hello World'"

Then, in another terminal, you can run a subscriber (Don't forget to source the workspace in every new terminal):

    $ ros2 topic echo /chatter

List existing nodes:

    $ ros2 node list
    publisher_std_msgs_String

List topics:

    $ ros2 topic list
    /chatter

Ros 2's version of rviz is

    $ rviz2

Category:

- Mathematics and science