topic通信publisher-python

topic通信publisher

实现

1. 创建package

ros2 pkg create --build-type ament_python py_pubsub

可以修改package.xml文件如下信息

<description>C++ client server tutorial</description>
<maintainer email="you@email.com">Your Name</maintainer>
<license>Apache License 2.0</license>

2. 编写publisher节点代码

2.1 编写代码

1. 在package的py_pubsub下创建publisher.py文件,代码如下

import rclpy
from rclpy.node import Node
from std_msgs.msg import String

class PyPublisher(Node):
    def __init__(self):
        super(PyPublisher, self).__init__('py_publisher')
        self.publisher = self.create_publisher(String, 'py_topic', 10)
        timer_period = 0.5  # seconds
        self.timer = self.create_timer(timer_period, self.timer_callback)
        self.i = 0

    def timer_callback(self):
        msg = String()
        msg.data = 'Hello World: %d' % self.i
        self.publisher.publish(msg)
        self.get_logger().info('Publishing: "%s"' % msg.data)
        self.i += 1

def main():
    rclpy.init()
    node = PyPublisher()
    rclpy.spin(node)
    node.destroy_node()
    rclpy.shutdown()
if __name__ == '__main__':
    main()

2.2 添加依赖

1. 打开package.xml文件,添加下面两行

<exec_depend>rclpy</exec_depend>
<exec_depend>std_msgs</exec_depend>

1. 打开 setup.py,保证如下字段和package.xml中相同

maintainer='YourName',
maintainer_email='you@email.com',
description='Examples of minimal publisher/subscriber using rclpy',
license='Apache License 2.0',

1. setup.py中console_scripts在字段的括号内添加以下行entry_points

entry_points={
        'console_scripts': [
                'talker = py_pubsub.publisher:main',
        ],
},

注意py_pubsub是包名 publisher是py文件名 main是执行的函数

3. 回到工程目录,编译代码

colcon build

4. 使构建生效

source install/setup.bash

5. 运行发布节点

ros2 run py_pubsub talker