Add minimal_timer example for rclpy to demonstrate periodic execution using create_timer()

[yadnyeshwar]

Description

The rclcpp examples repository contains minimal timer demonstrations (e.g., examples_rclcpp_minimal_timer), which help beginners understand how to execute periodic callbacks using ROS 2 timers.

However, the rclpy examples currently include:

• minimal_publisher
• minimal_subscriber
• pointcloud_publisher

but there is no minimal example demonstrating the use of create_timer() in Python.

Since timers are a fundamental mechanism in ROS 2 for running periodic tasks (such as sensor polling, monitoring loops, or periodic logging), a minimal Python example could help beginners understand this concept more easily.

Proposed Addition

Add a simple example under:

rclpy/topics/minimal_timer/

Possible structure:

rclpy/timer/minimal_timer/
 ├── minimal_timer.py
 └── README.md

The example could demonstrate:

• Creating a ROS 2 node
• Creating a timer using create_timer()
• Executing a periodic callback
• Logging output at fixed intervals

Motivation

This would:

• Improve parity between rclcpp and rclpy examples
• Help beginners understand periodic execution in ROS 2
• Provide a simple reference implementation for timers in Python

If this addition is considered useful, I would be happy to implement the example and submit a PR.

[alsora]

The publisher examples contain a timer https://github.com/ros2/examples/blob/rolling/rclpy/topics/minimal_publisher/examples_rclpy_minimal_publisher/publisher_member_function.py

Feel free to add a dedicated timer example, but IMO it's not absolutely necessary as it would be identical to that, but without the publisher

[yadnyeshwar]

Thanks for the clarification!

I’ve added a minimal example demonstrating the use of create_timer() without publishing, so it focuses purely on timer usage.

PR: #437