Attention: Answers.ros.org is deprecated as of August the 11th, 2023. Please visit robotics.stackexchange.com to ask a new question. This site will remain online in read-only mode during the transition and into the foreseeable future. Selected questions and answers have been migrated, and redirects have been put in place to direct users to the corresponding questions on Robotics Stack Exchange. Additional details are available here.

ROS spin and initialize

asked 2016-08-16 17:25:50 -0600

demi H
1 ●2 ●4 ●3

Hi. I'm new to ROS and I'm working with ros cpp. I have a question.

I know that if I call ros::spin(), then it enter a loop, pumping callbacks. But there are certain function that I just want to call, only once in the whole execution time.(and probably at the beginning) Like initializing device(not ros::init), setting which device to use through stdin.

I know that i can use inifinite while loop, but I don't think that it's a good idea. Because ros::spin() is made for that purpose.

Is there any function to solve this problem?

edit retag flag offensive close merge delete

Comments

Is there anything that prevents you from doing all of your initialization before you call ros::spin()?

ahendrix ( 2016-08-16 21:03:15 -0600 )edit

add a comment

1 Answer

Sort by » oldest newest most voted

answered 2016-08-17 01:14:10 -0600

Mark Rose

1563 ●8 ●17 ●21

@ahendrix is right, you can just perform initialization in your main function, either before or after initializing the node. You only call ros::spin() if all of your functionality is handled in subscriber callbacks. Often, nodes need to do things periodically, so they use an infinite loop, but don't execute continuously. Instead, they often set up a ros::Rate variable and use a combination of ros::spinOnce() and ros::Rate.sleep(). See callbacks and spinning for more info and other threading models. The other links on that page are also worth a look.

edit flag offensive delete link

add a comment

Question Tools

1 follower

Stats

Asked: 2016-08-16 17:25:50 -0600

Seen: 914 times

Last updated: Aug 17 '16

ROS spin and initialize edit

Comments

1 Answer

Question Tools

Stats

Related questions

ROS spin and initialize