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Setting Up Dynamic Reconfigure for a Node

Description: Setting Up Dynamic Reconfigure for a Node

Keywords: dynamic_reconfigure configure cpp

Tutorial Level: INTERMEDIATE

A simple example of a dynamically reconfigurable node can be found under dynamic_reconfigure/test

Setting Up Dynamic Reconfigure for a Node

This example shows how to setup a dynamic reconfigure node to reconfigure variables in the ROS message driver_base/SensorLevels.h. Suppose you are adding the dynamic reconfigure server node to your package which we'll refer to as your_package from now on.

1. Make your package depend on dynamic_reconfigure by adding this line to your manifest.xml,

     <depend package="dynamic_reconfigure" />

2. or if your ROS distribution is Groovy or higher use this:

     <build_depend>dynamic_reconfigure</build_depend>
     <run_depend>dynamic_reconfigure</run_depend>

The example below will also need

•   <depend package="driver_base" />

• or if your ROS distribution is Groovy or higher use this:

    <build_depend>driver_base</build_depend>
    <run_depend>driver_base</run_depend>

• Create a configuration file, saved it as your_package/cfg/MyStuff.cfg:

  # Forearm camera configuration
  
  PACKAGE='your_package'
  import roslib; roslib.load_manifest(PACKAGE)
  
  from math import pi
  
  from driver_base.msg import SensorLevels
  from dynamic_reconfigure.parameter_generator import *
  
  gen = ParameterGenerator()
  angles = gen.add_group("Angles")
  #       Name                    Type      Reconfiguration level
  #       Description
  #       Default  Min  Max
  angles.add("min_ang",           double_t, SensorLevels.RECONFIGURE_STOP,
             "The angle of the first range measurement. The unit depends on ~ang_radians.",
             -pi/2,-pi, pi)
  angles.add("max_ang",           double_t, SensorLevels.RECONFIGURE_STOP,
             "The angle of the first range measurement. The unit depends on ~ang_radians.",
              pi/2, -pi, pi)
  gen.add("intensity",            bool_t,   SensorLevels.RECONFIGURE_STOP,
          "Whether or not the hokuyo returns intensity values.",
           False)
  gen.add("cluster",              int_t,    SensorLevels.RECONFIGURE_STOP,
          "The number of adjacent range measurements to cluster into a single reading",
           1, 0, 99)
  gen.add("skip",                 int_t,    SensorLevels.RECONFIGURE_STOP,
          "The number of scans to skip between each measured scan",
           0, 0,  9)
  gen.add("port",                 str_t,    SensorLevels.RECONFIGURE_CLOSE,
          "The serial port where the hokuyo device can be found",
          "/dev/ttyACM0")
  gen.add("calibrate_time",       bool_t,   SensorLevels.RECONFIGURE_CLOSE,
          "Whether the node should calibrate the hokuyo's time offset",
           True)
  gen.add("frame_id",             str_t,    SensorLevels.RECONFIGURE_RUNNING,
          "The frame in which laser scans will be returned",
          "laser")
  gen.add("time_offset",          double_t, SensorLevels.RECONFIGURE_RUNNING,
          "An offet to add to the timestamp before publication of a scan",
           0, -0.25, 0.25)
  gen.add("allow_unsafe_settings",bool_t,   SensorLevels.RECONFIGURE_CLOSE,
          "Turn this on if you wish to use the UTM-30LX with an unsafe angular range. Turning this option on may cause occasional crashes or bad data. This option is a tempory workaround that will hopefully be removed in an upcoming driver version.",
           False)
  
  exit(gen.generate(PACKAGE, "dynamic_reconfigure_node", "MyStuff"))

  ¹

• Make the .cfg file executable

  chmod a+x your_package/cfg/MyStuff.cfg

• Create a ROS node that processes callbacks, for example, save the following file as your_package/src/dynamic_reconfigure_node.cpp:

     1 #include <dynamic_reconfigure/server.h>
     2 #include <your_package/MyStuffConfig.h>
     3 
     4 void callback(your_package::MyStuffConfig &config, uint32_t level)
     5 {
     6   ROS_INFO("Reconfigure request : %f %f %i %i %i %s %i %s %f %i",
     7            config.groups.angles.min_ang,
     8            config.groups.angles.max_ang,
     9            (int)config.intensity,
    10            config.cluster,
    11            config.skip,
    12            config.port.c_str(),
    13            (int)config.calibrate_time,
    14            config.frame_id.c_str(),
    15            config.time_offset,
    16            (int)config.allow_unsafe_settings);
    17 
    18   // do nothing for now
    19 }
    20 
    21 int main(int argc, char **argv)
    22 {
    23   ros::init(argc, argv, "dynamic_reconfigure_node");
    24   dynamic_reconfigure::Server<your_package::MyStuffConfig> srv;
    25   dynamic_reconfigure::Server<your_package::MyStuffConfig>::CallbackType f;
    26   f = boost::bind(&callback, _1, _2);
    27   srv.setCallback(f);
    28   ROS_INFO("Starting to spin...");
    29   ros::spin();
    30   return 0;
    31 }
  

• Update your CMakeLists.txt to compile above by adding these lines

  # add dynamic reconfigure api
  rosbuild_find_ros_package(dynamic_reconfigure)
  include(${dynamic_reconfigure_PACKAGE_PATH}/cmake/cfgbuild.cmake)
  gencfg()
  rosbuild_add_executable(dynamic_reconfigure_node src/dynamic_reconfigure_node.cpp)

• or if your ROS distribution is Groovy or higher use this:

   . find_package(catkin REQUIRED COMPONENTS dynamic_reconfigure ) 
   . generate_dynamic_reconfigure_options( cfg/MyStuff.cfg)  
   . include_directories(${dynamic_reconfigure_PACKAGE_PATH}/cmake/cfgbuild.cmake) 
   . add_executable(dynamic_reconfigure_node src/dynamic_reconfigure_node.cpp)
   . add_dependencies(dynamic_reconfigure_node ${PROJECT_NAME}_gencfg)
   . target_link_libraries(dynamic_reconfigure_node ${catkin_LIBRARIES})

• rosmake your package and launch the node.

  rosrun your_package dynamic_reconfigure_node