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How to subscribe to a topic?

So I have used Map_server to get an occupancy grid of the map. So, this publishes two topics - /map and /map_metadata.

I have another node where I need to subscribe to these topics but I'm a bit confused with what to write. Here's what I have done till now.

    ros::init(argc, argv, "driver");
    ros::NodeHandle n("~");
    ros::Subscriber sub = n.subscribe("/map", 1000, ???);
    ???

I am confused with what to write where I've put '???'.

Asked by Parth2851 on 2019-12-12 08:28:55 UTC

Comments

In your '???' you must write a callback function. A callback function is function that activates when your subscriber reads data from the topic ( /map for your situation). In this tutorial it has the chatterCallback that only prints the data.

Asked by MichaelDUEE on 2019-12-12 09:14:39 UTC

Answers

Try this tutorial on for size: http://wiki.ros.org/ROS/Tutorials/WritingPublisherSubscriber%28c%2B%2B%29#roscpp_tutorials.2BAC8-Tutorials.2BAC8-WritingPublisherSubscriber.Writing_the_Subscriber_Node

Asked by stevemacenski on 2019-12-12 13:35:06 UTC

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