Closed Shiyu-Liu closed 3 years ago
vooon
commented
3 years ago That is weird. But maybe something else also different? Possibly some of the base messages are different (at compile time) so you got that.
Anyway that problem is lower level to mavros - somewhere at ros messaging. I suggest that if you update both sides it will start working.
Shiyu-Liu
commented
3 years ago That is weird. But maybe something else also different? Possibly some of the base messages are different (at compile time) so you got that.
Anyway that problem is lower level to mavros - somewhere at ros messaging. I suggest that if you update both sides it will start working.
Hi vooon, thanks for your reply. Actually I've updated the mavros on both sides, and they are already of the latest version. I tried to install a previous version(mavros 1.1.0) though on the Raspberry Pi, via source installation method. It seemed to start working, cause I don't have the error about data type and version stuff anymore. However, I got a lot of errors on plugin loading exception. An example of that is given here: Plugin landing_target load exception: Could not find library corresponding to plugin landing_target. Make sure the plugin description XML file has the correct name of the library and that the library actually exists. I've gotten dozen plugins failed to load while the others are successfully loaded.
I saw a similar topic about that plugin error. Gonna keep on doing my investigation on this issue.
vooon
commented
3 years ago Ensure that you sourced setup.bash file from your environment (workspace or install directory).
Then check that you have libmavros_extras.so. Error tells me that pluginlib sees extras plugin xml file, but could not find shared library.
Shiyu-Liu
commented
3 years ago Ensure that you sourced setup.bash file from your environment (workspace or install directory). Then check that you have
libmavros_extras.so. Error tells me that pluginlib sees extras plugin xml file, but could not find shared library.
Yes, you are right. I forgot to also compile the mavros_extras from source. After that, it's working.
However, I found an interesting thing about the mavros_msgs/State message. I checked the version of this msg by $ rosmsg md5 mavros_msgs/State. Then I found that the version associated with mavros_msgs 1.0.0 is ce783f756cab1193cb71ba9e90fece50, while the current version under mavros_msgs 1.5.0 is 65cd0a9fff993b062b91e354554ec7e9.
Compared to the error inside the first question I published, I understood that I got that problem before because my mavros_msg must have been on 1.0.0, (even though I checked that it was the latest version). So I removed everything about mavros and mavros_extras on my PC, and reinstalled them from binary, via the command: $ sudo apt-get install ros-melodic-mavros ros-melodic-mavros-extras. And the problem was solved. Now I have same version of mavros and mavros_msgs running on both sides without conflits.
Thanks for your kind replies anyway.
KhuongDiep911
commented
1 year ago 
Hello Shiyu-Liu,
Can you give me some advice on how to solve this problem? I am facing the problem that has some similarity with you and I don't know how to solve it. I have tried to replace the line "65cd0a9fff993b062b91e354554ec7e9" by the line "9e3d873fae342c8f48a8bd64c53d991e" in "/opt/ros/noetic/mavros_msgs/State.h" file but it didn't work. I also tried to uninstall and reinstall the mavros and mavlink too. Do you know how to solve it? I really need help!
Thank you in advance for your help!
MAVROS: 1.14.0 Mavros_msgs: 1.14.0 Mavlink: 2022.8.8 ROS: Noetic Ubuntu: 20.04
[ ] ArduPilot [ x ] PX4
Issue details
Hello Shiyu-Liu,
Can you give me some advice on how to solve this problem? I am facing the problem that has some similarity with you and I don't know how to solve it. I have tried to replace the line "65cd0a9fff993b062b91e354554ec7e9" by the line "9e3d873fae342c8f48a8bd64c53d991e" in "/opt/ros/noetic/mavros_msgs/State.h" file but it didn't work. I also tried to uninstall and reinstall the mavros and mavlink too. Do you know how to solve it? I really need help!
Thank you in advance for your help!
Platform
MAVROS: 1.14.0 Mavros_msgs: 1.14.0 Mavlink: 2022.8.8 ROS: Noetic Ubuntu: 20.04
Autopilot type
[ ] ArduPilot [ x ] PX4
Hello, I don't remember what exactly was the issue, but after reading my own answers to that issue almost two years ago, your problem might be solved by reinstalling on both sides (running your subscriber and publisher) the mavros and mavros_msg from binary: $ sudo apt-get install ros-noetic-mavros ros-noetic-mavros-extras.
KhuongDiep911
commented
1 year ago Hi,
I have tried this solution but it hasn't worked. In addition, I haven't run my code on a real drone yet. I am now doing my study on sitl and gazebo simulator. Unluckily, I am stuck with this problem.
Shiyu-Liu
commented
1 year ago Hi,
I have tried this solution but it hasn't worked. In addition, I haven't run my code on a real drone yet. I am now doing my study on sitl and gazebo simulator. Unluckily, I am stuck with this problem.
In this case, as you're running nodes on the same PC, there shouldn't be any issue related to the different versions. Maybe check your gazebo simulation environment (for simulating the mavros) and probably it is using mavros_msgs in an incompatible way. I cannot provide any more helps since I have totally moved to ros2 without using mavros any more. I hope you can find out the solution.
KhuongDiep911
commented
1 year ago Okay, I will try your suggestion. Thank you so much for your help!
Issue details
Hello guys, I am trying to run controller from my PC to control a Pixhawk-based quadrotor, with Ubuntu 18.04 OS installed both on my PC and Raspberry Pi. Everything was well configured but when I run the node, it shows an error on the Mavros node of the drone:
[ERROR] [1608214083.907738946]: Client [/autopilot_drone] wants topic /crazy2fly5/mavros/state to have datatype/md5sum [mavros_msgs/State/ce783f756cab1193cb71ba9e90fece50], but our version has [mavros_msgs/State/65cd0a9fff993b062b91e354554ec7e9]. Dropping connection.
After searching on line, I found that it might be a mavros version problem. However, I run the same operating system on both two sides with Ros Melodic installed. And the Mavros was installed also by the same procedure, the binary installation. So I am wondering if anyone has an idea about this?
I checked the mavros version, and provide the detailed information below.
MAVROS version and platform
Mavros: 1.5.0 ROS: Melodic Ubuntu: 18.04
The results when I checked both sides about the mavros version:
Raspberry Pi: $ rosversion mavros -> 1.5.0 $ rosversion mavros_msgs -> 1.5.0 $ rosversion mavlink -> 2020.11.11 $ apt list ros-melodic-mavros Listing... Done ros-melodic-mavros/bionic,now 1.5.0-1bionic.20201113.223737 arm64 [installed]
PC: $ rosversion mavros -> 1.5.0 $ rosversion mavros_msgs -> 1.5.0 $ rosversion mavlink -> 2020.11.11 $ apt list ros-melodic-mavros Listing... Done ros-melodic-mavros/bionic,now 1.5.0-1bionic.20201113.182456 amd64 [installed]
I am thinking now if this is because the mavros I installed on the Raspberry Pi has a more recent version ? (1.5.0-1bionic.20201113.223737 compared to xxxxxx.182456) I tried to upgrade that of my PC, but it said that it is already the latest version.
I will appreciate it if anyone has the similar experience and could share their ideas. Thanks !