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--- getting_started:ros [2021/03/29 15:35] – [Example for Making your EEROS Application a ROS Node] ursgraf
+++ getting_started:ros [2025/03/18 10:42] (current) – [EEROS Messages] ursgraf
@@ Line 1: / Line 1: @@
 ====== Interfacing with ROS ======
-[[http://www.ros.org/|ROS]] is a flexible framework for writing robot software. It is great collection of tools, libraries, and conventions. You can make use of ROS within EEROS in the following two ways.
+[[http://www.ros.org/|ROS]] is a flexible framework for writing robot software. It is great collection of tools, libraries, and conventions. EEROS supports the use of ROS1 or ROS2.
+  * [[getting_started:ros_prep|]]
+  * [[getting_started:ros_timing|]]
+  * [[getting_started:ros_example|]]
+  * [[getting_started:ros_run|]]
+You can make use of ROS within EEROS in the following two ways.
+===== EEROS Messages =====
+EEROS defines its own ROS message types. They correspond to EEROS [[eeros_architecture:control_system:signals|]]
+  * Analog Signal → **eeros_msgs::msg::AnalogSignal**
+    - timestamp
+    - array of float64 values
+  * Digital Signal → **eeros_msgs::msg::DigitalSignal**
+    - timestamp
+    - array of boole values
+These messages are fetched and built when building EEROS with ROS supprt and will be installed into the same directory as EEROS itself.
 ===== Using Publisher and Subscriber Blocks in the Control System =====
@@ Line 15: / Line 32: @@
 It is also possible to use ROS-topics alongside real hardware. You could determine a motor position by reading an encoder and set a control value for a motor. In parallel, you could publish the same values to ROS topics to visualize the state of the robot with [[http://wiki.ros.org/rviz|rviz]] (if you have a model of your robot) or you could monitor the values with a ROS tool like [[http://wiki.ros.org/rqt|rqt]].
-===== Preparations and Building =====
-ROS needs to be installed on the developer machine as well as on the target machine.
-Before a ROS application can be started, you need to run the ''setup.bash'' script of ROS. This can be done with
-<code>
-source /path_to_ros_installation/setup.bash
-</code>
-The same applies for building the EEROS library with ROS support and for building an EEROS application with ROS support. \\
-IMPORTANT If an integrated development environment such as ''kdevelop'' or ''Qt Creator'' is used, the IDE has to be started from a terminal after the ''setup.bash'' script has run.
-=== Building the EEROS library with ROS ===
-If you build the library with cmake, make sure you use the -DUSE_ROS=TRUE switch.
-An example of a cmake call could look like this:\\
-''cmake -DCMAKE_INSTALL_PREFIX="$install_dir" -DUSE_ROS=TRUE ..''
-Our build scripts already include this switch.
-===== Example for Making your EEROS Application a ROS Node =====
-The CMAKE file for the EEROS application using ROS has to be expanded as follows:
-<code>
-cmake_minimum_required(VERSION 3.5.1)
-project(testProject)
-set(CMAKE_CXX_STANDARD 14)
-## ROS
-message(STATUS "looking for package 'ROS'")
-find_package( roslib REQUIRED )
-if (roslib_FOUND)
-	message( STATUS "-> ROS found")
-	add_definitions(-DROS_FOUND)
-	include_directories( "${roslib_INCLUDE_DIRS}" )
-	message( STATUS "roslib_INCLUDE_DIRS: " ${roslib_INCLUDE_DIRS} )
-	list(APPEND ROS_LIBRARIES "${roslib_LIBRARIES}")
-	find_package( rosconsole REQUIRED)
-	list(APPEND ROS_LIBRARIES "${rosconsole_LIBRARIES}")
-	find_package( roscpp REQUIRED )
-	list(APPEND ROS_LIBRARIES "${roscpp_LIBRARIES}")
-else()
-	message( STATUS "-> ROS NOT found")
-endif()
-find_package(EEROS REQUIRED)
-include_directories(${EEROS_INCLUDE_DIR};${EEROS_LIBUCL_INCLUDE_DIR})
-link_directories(${EEROS_LIB_DIR};${EEROS_LIBUCL_LINK_DIR})
-add_executable(testProject main.cpp)
-target_link_libraries(testProject eeros ucl ${CMAKE_DL_LIBS} ${ROS_LIBRARIES})
-</code>
-Your test program might look like
-<code cpp>
-#include <eeros/control/ros/EerosRosTools.hpp>
-#include <ros/ros.h>
-#include <signal.h>
-int main(int argc, char **argv) {
-  ...
-  eeros::control::rosTools::initNode("eerosNode"); // initialize the ROS node in your main function and give it a name.
-  ros::NodeHandle handle; // start the internal node
-  log.info() << "ROS node initialized.";
-  signal(SIGINT, ...);
-  ...
-</code>
-All ROS tools such as ''rqt'' will list your EEROS application under the name ''eerosNode''. \\
-If you want to register a signal handler, e.g. for shutting down a system (see [[getting_started:practical_problems:abort|]]), you have to register it after the ROS node is initialized.
-The ROS node will properly shut down as soon as the last node handler is destroyed when going out of scope.
-===== Running your Application =====
-An EEROS application using ROS needs to be started with super user privileges. Further,
-ROS needs some system variables, like ''ROS_MASTER_URI'', which are defined by the ''setup.bash'' script of ROS.
-To forward these variables to the super user process, the option //-E// has to be used.
-<code>
-$ sudo -E ./application
-</code>