Help regarding writing a ros2 wrapper over masterboard_sdk!

Software
1

Hi! I am trying to write a ROS2 node to publish IMU messages using master board SDK. I am currently stuck with an user permission issue. To access the ethernet port sudo permission is needed , however it also changes the environment variables is such a way that, executable is not able to find ros related libraries. is there a way to access the port without using sudo ?

2

You can change the capabilities of your executable to have access to raw sockets like this

sudo setcap cap_net_admin,cap_net_raw+ep <your_executeable>

However, note that this comes with some downsides. Once you change the capabilities, your LD_LIBRARY_PATH is set to zero for security reason. This restricts what your executeable can use.

Another option is to start a session as root and source sudo again (that’s what I am doing):

sudo -s  # Note the `-s`
source /opt/ros/dashing/setup.bash # Or whatever distro you are using

# Then run your executeable here
./your_executeable
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3

Hi ! jviereck .

I tried both the approaches . But the environment path changes and thus not able to access any of the ros library files.

Yours Sincerely,
S.Shyam

4

The easiest you can do is running as root user:

  • compile your code as $USER (yourself)
  • spawn a terminal and change user to root: sudo su
  • source the different ros workspace:
    • source /opt/ros/dashing/setup.bash
    • source ~/user_workspace/instal/seutp.bash
  • run the node: ros2 run package_name node_name

Let us know if you still have trouble.

ps: if you tried the option above know that using setcap cancel the use of the LD_LIBRARY_PATH by the binary hence it won’t see ANY dependencies. You can just delete the binary and recompile it. Or look at how to cancel the setcap

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5

For book keeping here is the solution:

6

@siva_uchiha can you share more information about your use of ROS2 in the context of ODRI?

AFAIK currently there already is a ROS2 package for Bolt, but not for SOLO (12).
(Cf. General Issues Solo12 - Calibration & Driver Errors and GitHub - stack-of-tasks/ros2_control_bolt)

7

Dear @andreasBihlmaier
We splitted the hardware support for ODRI from BOLT:
stack-of-tasks / ros2_hardware_interface_odri

I juste created a new repository for SOLO here:
stack-of-tasks / ros2_control_solo

The work to be done is:
1/ Make sure that the new URDF file is using ros2_hardware_interface_odri
2/ Make some tests on the real hardware with standard ros2_controller
3/ Split the gazebo plugin from ros2_control_bolt to use it with both ros2_control_solo and ros2_control_bolt

Any feedback welcome.

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8

Hi, I am trying to get root permission of ros2 node and found that the root node cannot communicate with non-root node, but I found there is root(control-node) and non-root node(rviz) mixed in the launch file.

Did you notice that issue that non-root node cannot pub/sub with root node?

Thanks.

9

@ZhenshengLee the root cause of your problem is likely related to a quirk of DDS on localhost (see here for some background information). The workaround is to add a custom DDS config for root:

<?xml version="1.0" encoding="UTF-8" ?>
<!-- export FASTRTPS_DEFAULT_PROFILES_FILE=$HOME/fastdds_root_workaround.xml -->
<profiles xmlns="http://www.eprosima.com/XMLSchemas/fastRTPS_Profiles" >
    <transport_descriptors>
        <transport_descriptor>
            <transport_id>CustomUdpTransport</transport_id>
            <type>UDPv4</type>
        </transport_descriptor>
    </transport_descriptors>

    <participant profile_name="participant_profile" is_default_profile="true">
        <rtps>
            <userTransports>
                <transport_id>CustomUdpTransport</transport_id>
            </userTransports>

            <useBuiltinTransports>false</useBuiltinTransports>
        </rtps>
    </participant>
</profiles>

Before running the ODRI node as root, run export FASTRTPS_DEFAULT_PROFILES_FILE=$HOME/fastdds_root_workaround.xml (assuming you have placed the content above in a file at $HOME/fastdds_root_workaround.xml).

Then non-root ROS 2 nodes should be able to communicate with those run as root.

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