pcler's profile - activity

Hi everyone. Recently I met a question when I read something about "latch" in Publisher. On the Publisher wiki page, "latch" is described as:(http://wiki.ros.org/rospy/Overview/Publishers%20and%20Subscribers)

    "Enable 'latching' on the connection. When a connection is latched, the last message published is saved and sent to any future subscribers that connect. This is useful for slow-changing or static data like a map."

Now I am so confused that [when a node subscribes a message from a topic, will this message disappears? If not, than what is "latch" for? Anyhow the last message will NOT disappear.]

PS. I have done some experiments. When several nodes subscribe a same topic, they always get the same messages content from that topic. And this can also explain how qrt_plot works.(It always subscribe messages from some topics but it never affects other nodes working)

Yes, I can find the relative .py file of the message now. Now it seems that the pre-build of driver_base succeeded! Thank you so much!

I use "catkin_make --pkg driver_base" to pre-build the pkg. But it doesn't work

Thank you for your reply! I have download the driver_base source and placed it inside the ROS workspace. There has been a command "find_package(catkin REQUIRED COMPONENTS nodelet image_transport dynamic_reconfigure driver_base gazebo_plugins)" in the CMakeLists of hector_gazebo_thermal_camera

Recently I am building hector_quadrotor(http://wiki.ros.org/hector_quadrotor) package. It needs another package named hector_gazebo_thermal_camera(inside http://wiki.ros.org/hector_gazebo ).

Using catkin_make, the building is successful on X86-Ubuntu14.04-Indigo, but failed on ARMv7l-Ubuntu14.04-Indigo. The error message is showed below:

[ 13%] Generating dynamic reconfigure files from cfg/GazeboRosThermalCamera.cfg: /home/chris/ros_ws/devel/include/hector_gazebo_thermal_camera/GazeboRosThermalCameraConfig.h /home/chris/ros_ws/devel/lib/python2.7/dist-packages/hector_gazebo_thermal_camera/cfg/GazeboRosThermalCameraConfig.py
Traceback (most recent call last):
File "/home/chris/ros_ws/src/hector_gazebo/hector_gazebo_thermal_camera/cfg/GazeboRosThermalCamera.cfg", line 5, in <module>
    from driver_base.msg import SensorLevels
ImportError: No module named msg
make[2]: *** [/home/chris/ros_ws/devel/include/hector_gazebo_thermal_camera/GazeboRosThermalCameraConfig.h] Error 1
make[1]: *** [hector_gazebo/hector_gazebo_thermal_camera/CMakeFiles/hector_gazebo_thermal_camera_gencfg.dir/all] Error 2
make[1]: *** Waiting for unfinished jobs....

P.S. It is hard to install dependencies into ARM platform. Because most of them don't provide the ARM versions. I built a lot of dependencies from source. Will this error is leaded by the dependency mistaking installed?

Thank you for helping me out!

Thank you so much! After I add 2G more swap then this error disappeared. The platform already owns 2G memory. I think the linking job of the package is really heavy

Thank you so much! It does be the problem of memory limited! This error came out on different object file, so at first I was not sure whether it was the problem of compiler.

Hi, all

I am having trouble with catkin_make mavros package error recently. It kept failing and saying:

c++: internal compiler error: Killed (program cc1plus)
Please submit a full bug report,
with preprocessed source if appropriate.
See <file:///usr/share/doc/gcc-4.8/README.Bugs> for instructions.
make[3]: *** [mavros/mavros/CMakeFiles/mavros.dir/src/lib/uas_stringify.cpp.o] Error 4
make[3]: *** Waiting for unfinished jobs....
c++: internal compiler error: Killed (program cc1plus)
Please submit a full bug report,
with preprocessed source if appropriate.
See <file:///usr/share/doc/gcc-4.8/README.Bugs> for instructions.
make[3]: *** [mavros/mavros/CMakeFiles/mavros.dir/src/lib/uas_data.cpp.o] Error 4
make[2]: *** [mavros/mavros/CMakeFiles/mavros.dir/all] Error 2
make[1]: *** [mavros/mavros/CMakeFiles/mavros.dir/rule] Error 2
make: *** [mavros] Error 2
Invoking "make mavros -j4 -l4" failed

I am using an armv7l embed platform.

The mavros package is clone from https://github.com/mavlink/mavros , master branch.

Using ROS Indigo and Ubuntu 14.04

I would be really grateful if somebody can do any help. Thank you so much!