Clone the repo to your colcon_ws
cd colcon_ws/src
git clone https://github.com/dasc-lab/ros2-ping
Build the workspace
cd colcon_ws
colcon build
Source the workspace
source install/setup.bash
One one terminal, start pong node
ros2 run ping pong
This node waits for messages on the /ping topic. When it receives something, it will republish the same message to the /pong topic.
On the other terminal, start the ping node
ros2 run ping ping
This node sends out a message on the ping topic every 500ms.
Whenever it receives a message on the pong topic, it alculates the time difference.
It prints the time difference to console, and also publishes it to the /round_trip topic as a builtin_interfaces::msg::Duration msg.
One a single computer, the ping should be about 1 ms.