rOS | Raspberry Pi audio player

This code:

handle = dlopen("./rk4.so", RTLD_LAZY);

will succeed if and only if there is rk4.so in the current directory. In particular, it will ignore any LD_LIBRARY_PATH setting.

This is working as designed.

If you want dlopen to respect LD_LIBRARY_PATH, change it like so:

The floating of .talent is most likely the culprit. When floating elements the parent looses track of their height, so if you check the dev tools you will most likely find out the divs with the class yui-gf are actually ending there.

Remove the floating and width of the .talent and try using grid on the parent to align its childs in columns.

The reason why this does not work is that your code gets compiled and is then placed inside the catkin_ws/devel/lib/ folder (lib not include!). Then when you launch the code it will look only in paths relative to the executable. This means you would actually have to place it inside the catkin_ws/devel/lib/ folder. The problem with that is though that as soon as you clean the workspace all of these directories will be deleted and you would have to re-copy all the files to it after each catkin clean.

For this purpose the ROS C++ API has though functions that allow you to browse the folder of a given package inside the catkin_ws/src folder or display all available packages when including the header file ros/package.h:

Rerunning the command rosrun turtlebot3_bringup create_udev_rules helps. Although it sometimes also doesn't. I ran this command on the one day, it worked. The day after: it didn't. Two days after that (today) it did work again.

You can give it a try.

Update: Not for long.. after the third bringup it again doesn't work..

ROS is intended for all nodes to run continuously until shutdown. Nevertheless there are some ideas that may help you to find a workaround:

• You could use system() in your code. Use this with wisdom since there are some use cases where use this call is not recommended.
• The launch files will help you to starting and stopping nodes programmatically. Check roslauch API, more concretely the Node Arguments.
• At least for killing there is an xmlrpc shutdown call, which is what rosnode kill uses. Sending SIGINT would also be OK as ROS installs a SIGINT handler.

Just had a similar issue and for me, this fixed it. Basically, I had add the new repository key and delete the old one. Listing the commands here for convenience:

One thing that immediately jumps to my eye is that you have actually put std_msgs::String::ConstPtr as the topic type but have topics /ecu_pcl and /velodyne_points which should not be of type std_msgs::String but instead should have a different data types, point clouds I assume, so something like sensor_msgs::PointCloud2. Therefore you would have to modify the callbacks to their correct data types, e.g. sensor_msgs::PointCloud2::ConstPtr.

What surprises me as well is the message roswtf gives you:

How can I solve this issue?

The memory available for automatic objects is typically very limited. As such, you must allocate all huge objects dynamically. Otherwise your variables will likely consume all of the memory reserved for automatic objects, which results in ... stack overflow.

Having huge member variables would not be a problem if all instances of the class were allocated dynamically, but since that restriction is hard to enforce, it is usually best to simply not have huge member variables.

Your arrays vis and frontier_vis are huge. Simple solution: Use std::vector.

For msg you should use: