Lab1 (4%)

Prelab (1%)

Before coming to the first lab, you are required to:

Form your team of 5
Install Ubuntu 18.04 on your computer

Readings

Notes on Ubuntu Installation

What You Will Need

Your computer with ubuntu installed

Learning Outcomes

By the end of Lab 1, you will have learnt:

Basic Linux bash commands
Ubuntu’s package manager (apt)
Understand system variables (.bashrc)
Install ROS Melodic
Familiarize with your limo

Installing ROS Melodic

Setup sources.list
To install ROS, we will have to prepare your computer to accept software from packages.ros.org. To do that we have to add the ROS apt repository to our system’s apt repository source index.
```
 sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list'
```
Command breakdown:
- sudo - This command temporarily gives you administrator privileges to run certain commands.
Setup apt key
To get any software from a apt server, we have to get the key to that apt server.
```
sudo apt install curl # if you haven't already installed curl
curl -s https://raw.githubusercontent.com/ros/rosdistro/master/ros.asc | sudo apt-key add -
```
Command breakdown:
- apt - apt is ubuntu’s package manager used to get/remove software from apt servers.
Installing ros
```
 sudo apt update
 sudo apt install ros-melodic-desktop-full
```
Command breakdown:
- apt update - This fetches any available updates from all apt servers. This does not install any updates, but rather just informs our system that a update is available.
- apt install - This attempts to install a specified package, this installs latest package version available (ROS melodic in this case).
Environment setup
In order to use our newly installed ROS, we have to somehow inform our terminal where to find this new package. In linux, we use something called environment variables to do this.
```
 echo "source /opt/ros/melodic/setup.bash" >> ~/.bashrc
 source ~/.bashrc
```
Command breakdown:
- echo - This makes bash repeat whatever you tell it to (“source /opt/ros/melodic/setup.bash” in this case)
- >> - This tells bash to place the text into a file (~/.bashrc in this case).
- source - This essentially runs a file containing bash commands.
- ~/.bashrc - This is a special file presnet in the home directory that contains bash commands that is runned once every time you open a new terminal.
ROS dependencies
There are certain dependencies packages that ROS needs, that we have to apt install. These packages are…
- python-rosdep
- python-rosinstall
- python-rosinstall-generator
- python-wstool
- build-essential Using the information from step 3, install these dependencies. After installing these pacakges, run
```
 sudo rosdep init
 rosdep update
```
Verify installation
Now we can proceed with verifying our new ROS installation, by running
```
roscore
```
If there are no errors, congratulations on installing ROS successfully.

Getting to know your LIMO

LIMO User manual and start guide