jhelovuo/ros2-client

syncing time across nodes

Closed this issue · 5 comments

i-am-logger commented

Hi,

How do I sync time across nodes? is there something like ROSTime and SystemTime? any support for the /clock topic like ROS2?

jhelovuo commented

ros2-client 0.7.0 has been released. It has support for ROSTime and the /clock topic.

Is this what you were missing?

i-am-logger commented

yes, exactly! need it for time sync/realtime

btw, any examples on how to use it?

jhelovuo commented

Yes. There are example programs time_broadcaster and time_reporter.

The broadcaster just periodically sends time updates over the /clock topic, so it is a very simple simulated clock. You can make it run slower or faster than real time by changing the source code.

time_reporter periodically reports the current ROSTime. It is configured to have the ROS parameter use_sim_time = true by default, so it will report the simulated time. If there is no-one broadcasting the time, the simulated time will be stuck at zero timestamp.

The parameter use_sim_time can be changed at runtime using e.g. the rqt tool's Dynamic Reconfigure plugin. This should change the clock source between the simulated and real system clock.

i-am-logger commented

amazing, thank you...

So i guess my next step is to report my gps sensor on /clock