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