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ros-drivers / rosserial

A ROS client library for small, embedded devices, such as Arduino. See: http://wiki.ros.org/rosserial
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rosserial server doesn't work when used by roslaunch #458

Open PaddyCube opened 4 years ago

PaddyCube commented 4 years ago

Hello,

I'm developing a robot which uses a ESP8266. ROS runs on a virtual machine on my PC. I was able to get a simple HelloWorld example running over wifi but for some reasons, it acts different depending on how I start rosserial server.

If i call it this way rosrun rosserial_python serial_node.py tcp

it works as expected. Topics are registered correctly and I can echo messages.

However, if I use this command roslaunch rosserial_server socket.launch

it seems fine, ESP8266 device reported that it is able to connect. But there are no topics registered and also no echo.

romainreignier commented 4 years ago

Note that these two lines are calling two different nodes, the first one is this Python node and in the second, the launch calls the rosserial_server C++ node.

To keep using the Python node, you should write the launch file yourself. It should looks like:

<launch>
  <node pkg="rosserial_python" type="serial_node.py" name="rosserial_python" args="tcp">
</launch>
PaddyCube commented 4 years ago

Hello, thanks for clarification. But I'm still confused why they act different. From my understanding of ROS (I'm totally beginner), it should not matter if it is written in C++ or Python.

romainreignier commented 4 years ago

Indeed, the language itself does not matter but here, the implementation is different.

What I mean is that it is not so strange to see differences switching between both.

Make sure to use the correct settings (port and address). Also note that rosserial_server recently changed. If you are not using the latest version from git, make sure that the message_info_service.py node is also launched.

viso951 commented 3 years ago

@PaddyCube I am experiencing problems connecting my ESP to the rosserver, can you specify please the ROS, ubuntu and rosserial version you are using?

romainreignier commented 3 years ago

I am not currently using rosserial on ESP. But last time I tried was on Ubuntu 18.04, ROS Melodic and released version of rosserial.

hariharan382 commented 2 years ago

Hello,

I'm developing a robot which uses a ESP8266. ROS runs on a virtual machine on my PC. I was able to get a simple HelloWorld example running over wifi but for some reasons, it acts different depending on how I start rosserial server.

If i call it this way rosrun rosserial_python serial_node.py tcp

it works as expected. Topics are registered correctly and I can echo messages.

However, if I use this command roslaunch rosserial_server socket.launch

it seems fine, ESP8266 device reported that it is able to connect. But there are no topics registered and also no echo.

Can you please paste working code ,I am confused a lot because there is no proper documentation for this issue

Tianyuan-Wang commented 1 year ago

I got the same issue with roslaunch rosserial_server socket.launch. My setup is STM32 (FreeRTOS+LwIP) -- Melodic. Issue solved with using rosrun rosserial_python serial_node.py tcp. (Didn't know that rosserial_python also has support for ETH connection.) It seems the rosserial_server stops listening the port and causes LwIP ERR_RST and then ERR_CONN error codes. Same error codes can be replicated through a test TCP connection with server side shutdown when client keeps sending. Or maybe some other reason that hide behind.