Wrote a simple chat application consisting of 2 nodes in :::ROS, Implementation of basic subscriber-publisher,using the concept of multithreading using AsyncSpinner in ROS.
- Ubuntu version : 20.04 / 18.04
- ROS version : Noetic / Melodic
- Editor used : Vscode
- Compiler : catkin
git clone https://github.com/jerinpeter/ChatApp
cd ..
catkin_make
rosrun ChatApp speaker
rosrun ChatApp microphone
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Uses 2 nodes Speaker and Microphone
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Both the nodes subscribe and publish to each other
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Used 2 topics
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/tomic - for publishing msg from speaker node to microphone node, [subscribed by microhone node]
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/tospeaker - for publishing msg from microphone node to speaker node, [subscribed by speaker node]
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In this package we have 2 nodes, a speaker and a microphone
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speaker is publishing msgs in the main func inside a while loop and a simple callback function is written to receive messages from the mic
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All user callbacks will be called from within the ros::spin() call. ros::spin() will not return until the node has been shutdown, either through a call to ros::shutdown() or a Ctrl-C
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Thus affecting the publishing of the messages from the speaker node in the absense of an Async spinnner
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The main problem arises in the microphone node where the publishing is executed in the callback func. which maybe delayed as it is waiting for the user i/p.
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Thus resulting in messegs not getting transmitted from the speaker node or not getting published from the microphone node.
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The standard ROSCPP spinner (ros::spin()) is single threaded, meaning it will only execute callbacks one by one.
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On the other hand Async Spinner is a threaded spinner and callbacks will have it's own thread
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It is ideal in dealing with complicated callback funtions
