In this exercise, we will setup ROS to be used from the terminal, and start roscore
In order to start programming in ROS, you should know how to install ROS on a new machine as well and check that the installation worked properly. This module will walk you through a few simple checks of your installed ROS system. Assuming you are working from the VM, you can skip any installation instructions as ROS is already installed.
Scan-N-Plan Application: Problem Statement¶
We believe we have a good installation of ROS but let’s test it to make sure.
Scan-N-Plan Application: Guidance¶
If you are ever having problems finding or using your ROS packages make sure that you have your environment properly setup. A good way to check is to ensure that environment variables like ROS_ROOT and ROS_PACKAGE_PATH are set:
printenv | grep ROS
If they are not then you might need to ‘source’ some setup.*sh files.
In a “bare” ROS install, you will need to run this command on every new shell you open to have access to the ROS commands. One of the setup steps in a typical ROS install is to add that command to the end of your
~/.bashrcfile, which is run automatically in every new terminal window. Check that your
.bashrcfile has already been configured to source the ROS-melodic
This process allows you to install several ROS distributions (e.g. indigo, kinetic, melodic) on the same computer and switch between them by sourcing the distribution-specific
roscore is a collection of nodes and programs that are pre-requisites of a ROS-based system. You must have a roscore running in order for ROS nodes to communicate. It is launched using the roscore command.
roscore will start up:
- a ROS Master
- a ROS Parameter Server
- a rosout logging node
You will see ending with
started core service [/rosout]. If you see
roscore: command not foundthen you have not sourced your environment, please refer to section 5.1. .bashrc Setup.
To view the logging node, open a new terminal and enter:
The logging node is named /rosout
Press Ctrl+C in the first terminal window to stop roscore. Ctrl-C is the typical method used to stop most ROS commands.