msgs

$catkin_create_pkg <"packageName"> <depends..> roscpp std_msgs message_generation

$cd <"packageName">

$mkdir msg

$cd msg

$vim <"fileName">.msg

# Make a file <"messageName">.msg

time stamp
int32 data

$cd ..

$mkdir src

$cd src

$vim <"publisherName">.cpp

#include "ros/ros.h"
#include "packageName/messageName.h"

int main(int argc, char** argv)
{
	ros::init(argc, argv, "publisherNmae");
    ros::NodeHandle nh;
    
    ros::Publisher pub = nh.advertise<packageName::messagename>("topicName", "queueSize");
    
    ros::Rate loop_rate(Hz);
    packageName::messageName "variable(msg)";
    
    int cnt = 0;
    
    while(ros::ok())
    {
    	msg.stamp  = ros::Time::now();
        msg.data = cnt;
        ROS_INFO("Send msg: %d", msg.stamp.sec);
        ROS_INFO("Send msg: %d", msg.stamp.nsec);
        ROS_INFO("Send msg: %d", msg.data);
        pub.publish(msg);
        cnt++;
        loop_rate.sleep();
    }
    
	return 0;
}

// publisherName.cpp

 

$vim <"subscriberName">.cpp

#include "ros/ros.h"
#include "packageName/messageName.h"

void msgCallback(const packageName::messageName::msg::ConstPtr& msg)
{
	ROS_INFO("receive msg: %d", msg->stamp.sec);
    ROS_INFO("receive msg: %d", msg->stamp.nsecs);
    ROS_INFO("recieve msg: %d", msg->data);
}

int main(int argc, char** argv)
{
	ros::init(argc, argv, "subscriberName");
    ros::NodeHandle nh;
    ros::Subscriber sub = nh.subscribe("topicName", queueSize, msgCallback);
    
    ros::spin();

	return 0;
}

// subscriberName.cpp

 

$cd ..

$vim CMakeLists.txt

cmake_minimum_required(VERSION 3.0.2)
project(msg_tutorial)

## Find catkin macros and libraries
## if COMPONENTS list like find_package(catkin REQUIRED COMPONENTS xyz)
## is used, also find other catkin packages
find_package(catkin REQUIRED COMPONENTS
  message_generation
  roscpp
  rospy
  std_msgs
)


## Generate messages in the 'msg' folder
add_message_files(
  FILES
  Mymsg.msg
)


## Generate added messages and services with any dependencies listed here
generate_messages(
  DEPENDENCIES
  std_msgs
)

################################################
## Declare ROS dynamic reconfigure parameters ##
################################################


## CATKIN_DEPENDS: catkin_packages dependent projects also need
## DEPENDS: system dependencies of this project that dependent projects also need
catkin_package(
#  INCLUDE_DIRS include
 LIBRARIES msg_tutorial
#  CATKIN_DEPENDS message_generation roscpp rospy std_msgs
#  DEPENDS system_lib
)

###########
## Build ##
###########

## Specify additional locations of header files
## Your package locations should be listed before other locations
include_directories(
# include
  ${catkin_INCLUDE_DIRS}
)


## The recommended prefix ensures that target names across packages don't collide
add_executable(msg_publisher src/msg_publisher.cpp)
add_executable(msg_subscriber src/msg_subscriber.cpp)

## Add cmake target dependencies of the executable
## same as for the library above
add_dependencies(msg_publisher ${${PROJECT_NAME}_EXPORTED_TARGETS} ${catkin_EXPORTED_TARGETS})
add_dependencies(msg_subscriber ${${PROJECT_NAME}_EXPORTED_TARGETS} ${catkin_EXPORTED_TARGETS})


## Specify libraries to link a library or executable target against
target_link_libraries(msg_publisher
  ${catkin_LIBRARIES}
)
target_link_libraries(msg_subscriber
  ${catkin_LIBRARIES}
)