• Create a package
• Compile the new package

• What is a node?
• Code
• Run
• Check node information

• How to communicate?
• Publisher
• Subscriber

• Public
• Private

• Basic Commands - Topic

• Write a .msg file
• Use the defined msg type
• Basic Commands - Message

• Write a .srv file
• Basic Commands - Service
• Service Class
• Server
• Client

• Write a .launch file
• Launch

• Subfolder (package)
  • Node (programs)
    • Service (functions)

Under the desired directory:

• mkdir -p ~/catkin_ws/src
• cd ~/catkin_ws/
• catkin init / catkin_make
  • Complete the stack stucture
  • Note: if encounter: catkin: command not found
    • sudo apt-get install python-catkin-tools

Under ~/.bashrc:

• source ~/catkin_ws/devel/setup.bash

• source /opt/ros/melodic/setup.bash
  • Find where ROS is installed on your computer
  • Enable us to use ROS functionalities (e.g.: roscore, rosrun)
• source ~/catkin_ws/devel/setup.bash
  • Activate the catkin workspace
• Note:
  • only one catkin_ws can run at one time, running source on a second catkin_ws will automatically deactivate the first one and activate the second.
  • To switch between workspaces, either source the corresponding setup.bash file (targetWS$ source devel/setup.bash) , or modify the ~/.bashrc file.
  • Run source ~/.bashrc after modification on it.

In VSCode:

• Generate task.json under .vscode
  • Terminal > Configure Default Build Task > catkin_make: build
• Teminal > Run build task
  • Difference between catkin_make: errors will show under the "problems" tab in VSCode