Waiting for subscriber to connect to /cmd

Arunkumar

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Mar 12, 2021, 7:06:22 AM3/12/21

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Hi everyone,

When I tried to teleop my robot from my development computer using this command I am getting messages

$ rosrun teleop_twist_keyboard teleop_twist_keyboard.py

Waiting for subscriber to connect to /cmd_vel

why I am getting this error?How to solve this??

P.S:

1.) Configuration of ROS_MASTER_URI and ROS_HOSTNAME is proper

2.) My robot and development computer are connected in the same network

3. I checked the ping also it is working fine

4.) I can also able to view laser data in rviz from my development computer

Thanks in advance,

Best Regards,

Arunkumar

Screenshot from 2021-03-12 17-27-48.png

tle...@gmail.com

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Mar 12, 2021, 11:12:25 AM3/12/21

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If you running the development computer on a vm tries to bridge the connection, that solved it for me.

Arunkumar

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Mar 12, 2021, 11:59:36 PM3/12/21

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Hi ,

Thanks for your reply,

Can you tell me what is vm??

As far as I concerned I am not running it in vm .

I just configured as development computer by the instruction in linorobot wiki page and tried to teleop it is not working.

P.S: Previously I used Desktop computer (kinetic) there it worked fine now I switched to a laptop (melodic) whether it will cause any issues??

Thanks ,

regards,

Arunkumar

tle...@gmail.com

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Mar 13, 2021, 12:51:57 PM3/13/21

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Vm is a virtual machine. I would check on developer computer if the topic is posted. by doing a rostopic list/echo then see if the cmd_vel is working. If that doesn't work, you can run the rqt part of the linorobot tutorial and in rqt there is an option to move to robot with a gui. I think its call robot steering or something. I had setup the ros on both my desktop and laptop and had no problem. I just don't know.

-Tan

Mohammed Sherief

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Mar 14, 2021, 9:59:50 AM3/14/21

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Hi Arun ,

If you are using DHCP on your network, there are chances that your robot IP or development PC IP got changed and hence you may face this problem.

Sherief.

Arunkumar

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Mar 14, 2021, 11:52:14 PM3/14/21

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Hi Sherief,

Thanks for your reply,

I have configured as an Static IP for both my Robot and development computer ( 192.168.1.x) both are connected in the same network .

Regards,

Arun

Arunkumar

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Mar 14, 2021, 11:58:38 PM3/14/21

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Hi tan ,

Thanks for your reply

Yeah I checked in my development computer by doing $ rostopic list while executing this command /cmd_vel is in the list of topics that is being publishing also when I tried to echo it just waiting and nothing is showing in the terminal also I tried $ rostopic hz /cmd_vel is gave me the no new messages as an Output.