Using ROS with pycrazyswarm

[COLVERTYETY]

Hello, I am an engineering student that is currently working with pycrazyswarm and I have a couple of questions about how to use crazyswarm with ros:

How do you access private ros params in a python script when the node has been renamed from a launch file?

You cannot start a node since that clashes with the pycrazyswarm.Crazyswarm() call.
I have been solving this problem on my side by manually parsing the sys.argv to retrieve the new node name.

How do you then pass the --sim arg to the crazyswarm node ?

I had to manually inject it in the sys.argv params that I pass to pycrazyswarm.Crazyswarm().

How do you solve the ros python path issues?

I have solved this issue on my side by pip installing the local pycrazyswarm folder.
This improves quality of life for development since symbolic links are no longer required.
This doesn't break back compatibility.

Would a helper lib/functions to assist with parsing the args and retrieving the params be an interesting contribution to this repo?
Maybe the pycrazyswarm lib should be pip installed by default? ( maybe make it available on pypi?)

Please met me know if I have been missing easy answers to my questions and if my ideas make sens.
Thank you.

[JeremieLGDP]

We've got the same issues here, I'd love to know the answers, thanks!

[whoenig]

I don't fully understand the problems. There seems to be one with "ROS params", and another one with "ROS path issues". Could you provide a small example for what you did, what behavior you got, and what behavior you want instead?

[COLVERTYETY]

if I try to use a launch file like this:

<launch>
    <node name="cf1" pkg="decenter" type="exemple3.py">
        <param name="cfid" value="1"/>
    </node>
    <node name="cf2" pkg="decenter" type="exemple3.py">
        <param name="cfid" value="2"/>
    </node>
</launch>

I'd like to read the private cfid param. However rospy.get_param("~cfid") won't work because that requires a rospy.init_node("my node") and that has a conflict with pycrazyswarm.Crazyswarm().

Trying to use --sim after the launch command doesn't work by default so you have to add the following lines to the launch file.

    <arg name="sim" default="False"/>
    <param name="sim" value="$(arg sim)"/>

And then you have to evaluate rospy.get_param("/sim") before calling pycrazyswarm.Crazyswarm(args="--sim").

for me the following line that I found in the docs doesn't work: #export PYTHONPATH=$PYTHONPATH:/path/to/crazyswarm/ros_ws/src/crazyswarm/scripts

I solved it by installing the pycrazyswarm lib. This removes the need for symbolic links everywhere.

I Hope that this helps you understand my problems.