slider_publisher

This packages proposes a slider-based publisher node similar to the joint_state_publisher, but that can publish any message or service.

Known bug version 2.2.0 introduced a rate parameter to choose at which rate messages are published. The default value for the rate was erroneously set to 0.1 while it should have been 10. This version was released in the Foxy September sync. A way to avoid the issue is to set the rate parameter to 10, or use the source version until the bug fix makes it to the next release.

Several examples are given: * ros2 launch example.launch for timestamped Twist (cmd_vel) * ros2 launch example.launch file:=Twist.yaml for non-timestamped Twist * ros2 launch example.launch file:=VelPose.yaml for 2 topics (Twist + Pose) * ros2 launch example.launch file:=MultiArray.yaml for a topic with 4 floats * ros2 launch gazebo_service.launch for a service call (uses gazebo_msgs)

Only numerical types or their derivatives can be publisher (ie there is no text input to change such value on-the-fly). Array-based messages are also possible for numerical values.

The packages reduces to a single node that has to be called with an argument leading to a YAML file with the following structure (examples corresponding to the VelPose.yaml file):

topic_to_be_published:  
    type: full message or service type               (geometry_msgs/Twist or geometry_msgs/msg/Twist to specify it is a message)  
    key_as_in_gui:                        (vx)  
        to: corresponding_message_field   (linear.x)  
        min: slider minimum value         (-1)  
        max: slider maximum value         (+1)  
        default: slider default value     (if not: (min+max)/2)
    other_key:  
        ...
other_topic_to_be_published:  
    type...

Hard-coded numeric values (bounds / constant values in messages) can be defined using fractions of pi.

3D rotations (ie quaternions) can be parameterized as roll / pitch / yaw (see RPY.yaml). While these fields are of course not part of a Quaternion message, the corresponding 3D rotation will be built and published.

If the type is a service interface then the corresponding slider will call the service, after waiting for the server.

Parameters

• config (string): this parameter has the same effect as the raw file argument, that is the path to the YAML configuration file
• rate (double): publication rate (0-100 Hz)