A small bit of code to allow Ouster OS1 data to be exported from ROS to an external C++ program using rosbridge. It should be modifiable to fit any ROS topic you want to make available to some external (potentially remote) process, though I don't claim that this is the most efficient way of doing so.*

These instructions are for Ubuntu 18.04, or 20.04 as noted. Melodic is the release name for 18.04, and Noetic is the release for 20.04. Anywhere melodic is used in a command substitute noetic or whatever the appropriate name is which corresponds to your distribution.

This repo includes modified code from easywsclient, which was published under the MIT license. A copy of the copyright notice and license is available in the easyws directory.

These instructions are directly from the ROS wiki

sudo sh -c 'echo "deb https://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list'

sudo apt-key adv --keyserver 'hkp:https://keyserver.ubuntu.com:80' --recv-key C1CF6E31E6BADE8868B172B4F42ED6FBAB17C654

sudo apt update

sudo apt install ros-melodic-desktop-full

You shouldn't need the full install but I didn't test it with the bare bones package

Also install rosbridge

sudo apt install ros-melodic-rosbridge-suite

echo "source /opt/ros/melodic/setup.bash" >> ~/.bashrc
source ~/.bashrc

For Ubuntu 18.04:

sudo apt install python-rosdep python-rosinstall python-rosinstall-generator python-wstool build-essential

For Ubuntu 20.04:

sudo apt install python3-rosdep python3-rosinstall python3-rosinstall-generator python3-wstool build-essential

sudo rosdep init
rosdep update

You need to build the Ouster PacketMsg and make it available to ROS.* One way to accomplish this is building Ouster's sample node.

source /opt/ros/melodic/setup.bash
git clone https://github.com/ouster-lidar/ouster_example.git
export CMAKE_PREFIX_PATH=path/to/ouster_example

Note that path/to/ouster_example is where you cloned the repo

mkdir -p myworkspace/src && cd myworkspace && ln -s /absolute/path/to/ouster_example ./src/ && catkin_make -DCMAKE_BUILD_TYPE=Release

echo "source path/to/myworkspace/devel/setup.bash" >> ~/.bashrc
source devel/setup.bash

This project uses Make

make

There are several steps to launching the rosbridge server and demo program, which require multiple terminals.

In the first terminal launch roscore

roscore

In a second terminal, begin the playback of the rosbag

rosbag play path/to/some/rosbag.bag --pause -r 0.1

Including --pause prevents the bag from playing immediately. Press space to unpause and begin playing.

The -r 0.1 limits the bag playback to 1/10th of real-time. This may be necessary to prevent packets from being dropped.

In a third terminal you can check that the topics are available

rostopic list

You should see the topics from your bag

user@VirtualBox:~$ rostopic list
/clock
/os1_node/imu_packets
/os1_node/lidar_packets
/rosout
/rosout_agg

Now you can launch the rosbridge server

roslaunch rosbridge_server rosbridge_websocket.launch

The default configuration opens the websocket on port 9090, which is precofigured in the client source code.

Finally, you can launch the client app

./bagman.elf

If something fails it's probably due to the setup files not being sourced; try re-opening the shell, or source them manually:

source /opt/ros/melodic/setup.bash
source path/to/myworkspace/devel/setup.bash

*I didn't try to understand how ROS works, I just needed to do this thing, so some steps may be unnecessary or inefficient