Waiting for an action server to become available...

[Illyvia]

Hello, I'm having trouble sending actions to the create3. I'm using a raspberry pi 400, running Ubuntu 22.04

pi@ubuntu:~$ cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=22.04
DISTRIB_CODENAME=jammy
DISTRIB_DESCRIPTION="Ubuntu 22.04.1 LTS"
pi@ubuntu:~$ ros2 topic list
/create/battery_state
/create/cmd_audio
/create/cmd_lightring
/create/cmd_vel
/create/dock
/create/hazard_detection
/create/imu
/create/interface_buttons
/create/ir_intensity
/create/ir_opcode
/create/kidnap_status
/create/mobility_monitor/transition_event
/create/mouse
/create/odom
/create/robot_state/transition_event
/create/slip_status
/create/static_transform/transition_event
/create/stop_status
/create/tf
/create/tf_static
/create/wheel_status
/create/wheel_ticks
/create/wheel_vels
/parameter_events
/rosout
pi@ubuntu:~$ ros2 action send_goal /dock irobot_create_msgs/action/Dock "{}"
Waiting for an action server to become available...

I've also tried this on a virtual machine running Ubuntu 20.04.5 LTS

ros@ROS2-VirtualBox:~$ cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=20.04
DISTRIB_CODENAME=focal
DISTRIB_DESCRIPTION="Ubuntu 20.04.5 LTS"
ros@ROS2-VirtualBox:~$ ros2 topic list
/create/battery_state
/create/cmd_audio
/create/cmd_lightring
/create/cmd_vel
/create/dock
/create/hazard_detection
/create/imu
/create/interface_buttons
/create/ir_intensity
/create/ir_opcode
/create/kidnap_status
/create/mobility_monitor/transition_event
/create/mouse
/create/odom
/create/robot_state/transition_event
/create/slip_status
/create/static_transform/transition_event
/create/stop_status
/create/tf
/create/tf_static
/create/wheel_status
/create/wheel_ticks
/create/wheel_vels
/parameter_events
/rosout
ros@ROS2-VirtualBox:~$ ros2 action send_goal /dock irobot_create_msgs/action/Dock "{}"
Waiting for an action server to become available...

I've also tried this with a lot of other actions.

[alsora]

What does ros2 action list returns?
Which version of ROS 2 are you using on the create 3 and on the other machines?

[alsora]

The command to invoke the dock action should then be

ros2 action send_goal /create/dock irobot_create_msgs/action/DockServo "{}"

Note how the action name is /create/dock and the action type is DockServo

[Illyvia]

That returns: The passed action type is invalid

[shamlian]

Not to butt in here, but I think this most recent problem with an invalid action type is because you have Humble messages installed on the machine upon which you're typing, while your robot is running Galactic.

[alsora]

Yes, as @shamlian said.
Make sure that you are interacting with the robot from a workstation with ROS 2 Galactic installed (I assume the 20.04 you mentioned above).

Communication between different ROS 2 distributions is not guaranteed to work.

[Illyvia]

Thanks so much!!!! I tried again on the virtual machine and it worked!!!

[iansexton1]

I’m having a similar issue after installing the Ubuntu 20.04 OS onto my Machine and going through all the setup steps. I confirmed communication to the robot by running the “ros 2 topic list” and “ros 2 action list” commands and got the below results. I then entered the undocking command, ros2 action send_goal /undock irobot_create_msgs/action/Undock "{} but the robot did not respond and got stuck “Waiting for an action server…”. I’ve already confirmed that I’m using the ‘Cyclone DDS” RMW.

[alsora]

Hi @iansexton1, as the output of your ros2 action list command shows, there isn't an action named /undock on your robot, but rather it's named /Nexton/undock.

Whenever you add a ROS namespace, then you need to remember to include it when sending commands or listening to topics.

The correct way to invoke the action is as follows:

ros2 action send_goal /Nexton/undock irobot_create_msgs/action/Undock "{}"