ROS2 foxy 学习2 : 话题topic通讯

Topics are one of the communication types that connects nodes.\话题是通讯方式

ros2 模块化设计，有很多节点 node,节点之间通讯通过topic进行。

• topic的作用相当于物理总线， 传输的内容就是message.
• 通讯模式： 可以同时 1对1 ； 1对多； 多对1

启动环境：
ros2 run turtlesim turtlesim_node

ros2 run turtlesim turtle_teleop_key

#打开ros graphic\
#rqt_graph is a graphical introspection tool. 
rqt_graph

The graph is depicting how the /turtlesim node and the /teleop_turtle node are communicating with each other over a topic. The