ROS2 之 自定义消息

包目录下建立目录
mkdir  pkg/{msg,srv,action}
在对应目录下制定 .msg  .srv  .action文件的消息格式.

数据类型的定义参考

## 修改 CMakeLists.txt

find_package(rosidl_default_generators REQUIRED)

rosidl_generate_interfaces(${PROJECT_NAME}
  "msg/Num.msg"
  "srv/AddThreeInts.srv"
 )
ament_export_dependencies(rosidl_default_runtime)

还有一种写法, 就是CMakefile设置变量
set(msg_files "msg/AddressBook.msg" )
rosidl_generate_interfaces(${PROJECT_NAME} ${msg_files} )

<build_depend>rosidl_default_generators</build_depend>

<exec_depend>rosidl_default_runtime</exec_depend>

<member_of_group>rosidl_interface_packages</member_of_group>

编译
colcon build --packages-select tutorial_interfaces
. install/setup.bash

ros2 interface show tutorial_interfaces/msg/Num
ros2 interface show tutorial_interfaces/srv/AddThreeInts

被引用的方法
代码
#include "tutorial_interfaces/msg/num.hpp" // CHANGE

CMakeLists.txt:
find_package(tutorial_interfaces REQUIRED) # CHANGE
ament_target_dependencies(talker rclcpp tutorial_interfaces) # CHANGE
ament_target_dependencies(listener rclcpp tutorial_interfaces) # CHANGE

package.xml
<depend>tutorial_interfaces</depend> --CPP
<exec_depend>tutorial_interfaces</exec_depend> -- python

------------------------------------------------
Srv文件加入
代码
#include "tutorial_interfaces/srv/add_three_ints.hpp" // CHANGE
from tutorial_interfaces.srv import AddThreeInts     # CHANGE

CMakeLists.txt修改
find_package(tutorial_interfaces REQUIRED) # CHANGE
ament_target_dependencies(server
  rclcpp tutorial_interfaces) #CHANGE

package.xml 修改
<depend>tutorial_interfaces</depend> -- CPP
<exec_depend>tutorial_interfaces</exec_depend> -- python

----------------------------------------------------------------------------------------------------------------------

.action 文件的编译

修改 CMakeLists.txt
find_package(rosidl_default_generators REQUIRED)

rosidl_generate_interfaces(${PROJECT_NAME}
  "action/Fibonacci.action"
)

修改 package.xml
<buildtool_depend>rosidl_default_generators</buildtool_depend>

<depend>action_msgs</depend>

<member_of_group>rosidl_interface_packages</member_of_group>


编译后查询是否ok, 例如
ros2 interface show action_tutorials/action/Fibonacci

使用 action