This is roughly what it looks like to adapt the roscpp talker to use a diagnosed updater and diagnosed publisher.
I haven't tested that this compiles, but it should be pretty close.
#include <ros/ros.h>
#include <std_msgs/String.h>
#include <diagnostic_updater/diagnostic_updater.h>
#include <diagnostic_updater/publisher.h>
#include <sstream>
int main(int argc, char **argv)
{
ros::init(argc, argv, "talker");
ros::NodeHandle n;
// The Updater class advertises to /diagnostics, and has a
// ~diagnostic_period parameter that says how often the diagnostics
// should be published.
diagnostic_updater::Updater updater;
double desired_freq = 10.0; // desired publish frequency
double min_freq = 9.0; // minimum frequency before error
double max_freq = 11.0; // maximum frequency before error
double freq_tolerance = 0.1; // Tolerance before stating error on publish frequency, fractional percent of desired frequencies.
int window_size = 100; // Number of samples to consider in frequency
double min_acceptable = 0.05; // The minimum publishing delay (in seconds) before publish times.
double max_acceptable = 0.15; // Maximum delay between message publish times
diagnostic_updater::DiagnosedPublisher<std_msgs::String> chatter_pub(n.advertise<std_msgs::String>("chatter", 1000),
updater,
diagnostic_updater::FrequencyStatusParam(&min_freq_, &max_freq_, freq_tolerance, window_size),
diagnostic_updater::TimeStampStatusParam(min_acceptable, max_acceptable)));
ros::Rate loop_rate(desired_freq);
int count = 0;
while (ros::ok())
{
std_msgs::String msg;
std::stringstream ss;
ss << "hello world " << count;
msg.data = ss.str();
ROS_INFO("%s", msg.data.c_str());
chatter_pub.publish(msg);
ros::spinOnce();
loop_rate.sleep();
++count;
}
return 0;
}
The CMakeLists.txt to build this node in the beginner_tutorials package should be:
cmake_minimum_required(VERSION 2.8.3)
project(beginner_tutorials)
## Find catkin and any catkin packages
find_package(catkin REQUIRED COMPONENTS roscpp diagnostic_updater std_msgs)
## Declare a catkin package
catkin_package()
add_executable(talker src/talker.cpp)
target_link_libraries(talker ${catkin_LIBRARIES})
