ROS节点通信Demo

news2024/11/26 15:35:21

0 开始之前

确保你已经安装了ROS (Robot Operating System)。

1 第一步：创建一个ROS包

在开始编程前，我们首先创建一个新的ROS包(package)。移动到你的catkin workspace的 'src' 文件夹下，然后运行以下命令：

cd ~/catkin_ws/src
catkin_create_pkg my_package std_msgs rospy roscpp

其中 my_package 是你的包名， std_msgs rospy roscpp 是该包依赖的包。

第二步：创建节点源代码文件

接下来，在你的包中创建一个新的C++ 源文件：catkin_ws/src/my_package/src

pub.cpp

#include <ros/ros.h>
#include <std_msgs/String.h>

int main(int argc, char **argv)
{
  ros::init(argc, argv, "talker");
  ros::NodeHandle nh;

  ros::Publisher chatter_pub = nh.advertise<std_msgs::String>("chatter", 1000);

  ros::Rate loop_rate(10);

  int count = 0;
  while (ros::ok())
  {
    std_msgs::String msg;
    std::stringstream ss;
    ss << "send test msg " << count;
    msg.data = ss.str();

    ROS_INFO("%s", msg.data.c_str());

    chatter_pub.publish(msg);

    ros::spinOnce();

    loop_rate.sleep();
    ++count;
  }

  return 0;
}

sub.cpp

#include <ros/ros.h>
#include <std_msgs/String.h>

void chatterCallback(const std_msgs::String::ConstPtr& msg)
{
  ROS_INFO("subscribe receive : [%s]", msg->data.c_str());
}

int main(int argc, char **argv)
{
  ros::init(argc, argv, "listener");
  ros::NodeHandle nh;

  ros::Subscriber sub = nh.subscribe("chatter", 1000, chatterCallback);

  ros::spin();

  return 0;
}

第三步：编辑CMakeLists.txt和package.xml

在你的 my_package 目录下，编辑 CMakeLists.txt 和 package.xml 文件，增加你需要的依赖和构建规则。

package.xml

<?xml version="1.0"?>
<package format="2">
  <name>my_package</name>
  <version>0.0.0</version>
  <description>The my_package package</description>

  <!-- One maintainer tag required, multiple allowed, one person per tag -->
  <!-- Example:  -->
  <!-- <maintainer email="jane.doe@example.com">Jane Doe</maintainer> -->
  <maintainer email="renjianhong@todo.todo">renjianhong</maintainer>


  <!-- One license tag required, multiple allowed, one license per tag -->
  <!-- Commonly used license strings: -->
  <!--   BSD, MIT, Boost Software License, GPLv2, GPLv3, LGPLv2.1, LGPLv3 -->
  <license>TODO</license>


  <!-- Url tags are optional, but multiple are allowed, one per tag -->
  <!-- Optional attribute type can be: website, bugtracker, or repository -->
  <!-- Example: -->
  <!-- <url type="website">http://wiki.ros.org/my_package</url> -->


  <!-- Author tags are optional, multiple are allowed, one per tag -->
  <!-- Authors do not have to be maintainers, but could be -->
  <!-- Example: -->
  <!-- <author email="jane.doe@example.com">Jane Doe</author> -->


  <!-- The *depend tags are used to specify dependencies -->
  <!-- Dependencies can be catkin packages or system dependencies -->
  <!-- Examples: -->
  <!-- Use depend as a shortcut for packages that are both build and exec dependencies -->
  <!--   <depend>roscpp</depend> -->
  <!--   Note that this is equivalent to the following: -->
  <!--   <build_depend>roscpp</build_depend> -->
  <!--   <exec_depend>roscpp</exec_depend> -->
  <!-- Use build_depend for packages you need at compile time: -->
  <!--   <build_depend>message_generation</build_depend> -->
  <!-- Use build_export_depend for packages you need in order to build against this package: -->
  <!--   <build_export_depend>message_generation</build_export_depend> -->
  <!-- Use buildtool_depend for build tool packages: -->
  <!--   <buildtool_depend>catkin</buildtool_depend> -->
  <!-- Use exec_depend for packages you need at runtime: -->
  <!--   <exec_depend>message_runtime</exec_depend> -->
  <!-- Use test_depend for packages you need only for testing: -->
  <!--   <test_depend>gtest</test_depend> -->
  <!-- Use doc_depend for packages you need only for building documentation: -->
  <!--   <doc_depend>doxygen</doc_depend> -->
  <buildtool_depend>catkin</buildtool_depend>
  <build_depend>roscpp</build_depend>
  <build_depend>rospy</build_depend>
  <build_depend>std_msgs</build_depend>
  <build_export_depend>roscpp</build_export_depend>
  <build_export_depend>rospy</build_export_depend>
  <build_export_depend>std_msgs</build_export_depend>
  <exec_depend>roscpp</exec_depend>
  <exec_depend>rospy</exec_depend>
  <exec_depend>std_msgs</exec_depend>


  <!-- The export tag contains other, unspecified, tags -->
  <export>
    <!-- Other tools can request additional information be placed here -->

  </export>
</package>

CMakeLists.txt

cmake_minimum_required(VERSION 2.8.3)
project(my_package)

## Find catkin and any catkin packages
find_package(catkin REQUIRED COMPONENTS roscpp rospy std_msgs genmsg)

## Declare ROS messages and services
# add_message_files(DIRECTORY msg FILES Num.msg)
# add_service_files(DIRECTORY srv FILES AddTwoInts.srv)

## Generate added messages and services
generate_messages(DEPENDENCIES std_msgs)

## Declare a catkin package
catkin_package()

## Build talker and listener
include_directories(include ${catkin_INCLUDE_DIRS})

add_executable(talker src/pub.cpp)
target_link_libraries(talker ${catkin_LIBRARIES})
add_dependencies(talker my_ros_package_generate_messages_cpp)

add_executable(listener src/sub.cpp)
target_link_libraries(listener ${catkin_LIBRARIES})
add_dependencies(listener my_ros_package_generate_messages_cpp)