INSTALLING LINUX AND ROS
In this article, we are going to install UBUNTU on a Virtual Machine and then install ROS melodic onto the Virtual Machine.
A virtual machine is a software that runs a second OS on your main host machine but without a hard disk partition. This way, one can run multiple VM’s with different operating systems, and even can be moved between different host machines. There are many VM software, notably Oracle’s VirtualBox, or Parallels, or VMWare. You can use any software you like, but I would prefer parallels as it is fast and stable for simulations using Gazebo which we will come across later in the blog.
Press the following for the download links:
Set up the software, they are pretty much straight forward.
Coming to the operating system, we are going to use UBUNTU 18.04, as it seems to be stable for the ROS API.
Setup the OS on the VirtualMachine Software.
Now, lets set up the main backbone for the whole publication. One could typically follow the setup instruction on ros.org, but I would prefer a different approach so that the workspace is always connected to ROS and you don’t need to define it every time you work on it. We are installing ROS MELODIC as at the moment it has the most prolonged support.
Setting up source space, so that the VM can accept software from ROS.
sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list'
Setting up the key, for your installation
sudo apt-key adv --keyserver 'hkp://keyserver.ubuntu.com:80' --recv-key C1CF6E31E6BADE8868B172B4F42ED6FBAB17C654
Now to the main installation.
sudo apt-get update
^^ To make sure the index of the operating system is up-to-date with all the software.
Now the system is ready to install ROS. There are many version of ROS MELODIC, a full desktop version install, then a version with barebones software. It will be preferred if the full desktop version is installed so it wouldn’t be a headache at the later stages.
sudo apt install ros-melodic-desktop-full
This will take time, be patient.
now the next step is to initialise rosdep, it helps you to instal other packages and dependencies for ROS.
sudo apt install python-rosdep python-rosinstall python-rosinstall-generator python-wstool build-essential
sudo apt install python-rosdep
sudo rosdep init
Now major part of the installation is done, but we still have to enable all the downloaded software.
In the bashrc file, add this specific line at the end
now save the file, and then
now ROS is enabled every time a new terminal window is opened.
Now creating a workspace where you would do the majority of your work.
in a new terminal window
mkdir -p ~/catkin_ws/src
mkdir = make directory
catkin_ws = name of you workspace
src = the folder with all the code in the workspace
now go to the root of the folder by
and create the source files for ROS by
Now the workspace is ready to develop ROBOTS!!
But wait, now every time you open the workspace to develop, you have to initialise ROS to the specific workspace, to counter that, lets define this workspace as your default workspace.
and then in the bottom most line add this
now the workspace if your default workspace.
To test that, in a terminal window type
if it leads to catkin_ws, then the whole installation is correct.
Next we will be learning about the basic elements of ROS.