Abdur Rosyid's Blog
Just a few notes on mechanical engineering and robotics
The following are some differences between ROS1 and ROS2. Difference 1: Master-Slave vs Distributed Network Architecture ROS1 communication is based on TCPROS (a custom TCP communication) with master-slave network architecture, where one computer/robot should serve as ROS Master while the others serve as slaves. If ROS Master fails, the whole network fails. ROS2 is based …
Below are the steps to create a ROS2 action using Python. Notice that we are going to have two packages involved: 1) a package called “my_package” which contains the action file, and 2) a package called “action_nodes_python” which contains the action server and client nodes. Separating the package which contains the action file(s) like this, …
Below are the steps to create a ROS2 action. Notice that we are going to have two packages involved: 1) a package called “my_package” which contains the action file, and 2) a package called “action_nodes_cpp” which contains the action server and client nodes. Separating the package which contains the action file(s) like this, in general, …
In ROS1, we write a launch file in XML. In ROS2, there are three ways to write a launch file: Using Python Using XML Using YAML Since the API of ROS2 launch is written in Python, you have a lower level access to the launch features if you write your launch file in Python. This …
The following are some common ROS1 and ROS2 CLI commands: ROS1 ROS2 Function rosrun ros2 run Running a node rosnode ros2 node Information about node rostopic ros2 topic Command for ROS topic roslaunch ros2 launch Command to launch a launch file rosservice ros2 service Command for ROS servide rospack ros2 pkg Information about package
Step 1: Create the service (.srv) file, namely ServiceName.srv, inside an “srv” folder. Step 2: Modify setup.py. Step 3: Modify package.xml. Step 4: Write the service_server node in the package subfolder inside the package folder. There are two ways to write a service_server node in Python: 1) old-school approach, and 2) member-function approach. The following …
Step 1: Create the service (.srv) file, namely ServiceName.srv, inside an “srv” folder.
Step 2: Modify CMakeLists.txt.
Add the following:
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find_package(builtin_interfaces REQUIRED) find_package(rosidl_default_generators REQUIRED) # and put below before ament_package(): rosidl_generate_interfaces(ros2_exercise_cpp "srv/ServiceName.srv" DEPENDENCIES builtin_interfaces ) |
There are three ways to to write a Python publisher in ROS2, namely:
Below is an example of each approach to write a Python node listening to “Hello World” stream. The code is taken from here: https://github.com/ros2/examples/tree/foxy/rclpy/topics/minimal_subscriber/examples_rclpy_minimal_subscriber
(more…)There are three ways to to write a Python publisher in ROS2, namely:
Below is an example of each approach to write a Python node publishing “Hello World”. The code is taken from here: https://github.com/ros2/examples/tree/foxy/rclpy/topics/minimal_publisher/examples_rclpy_minimal_publisher
(more…)There are three ways to to write a C++ publisher in ROS2, namely:
Below is an example of each approach to write a C++ node listening to “Hello World” stream. The code is taken from here: https://github.com/ros2/examples/tree/foxy/rclcpp/topics/minimal_subscriber
(more…)