Embedded Motion Control 2012/Installation
This manual describes how to the install the necessary and sufficient software to start programming the Jazz robot.
Go to The official Ubuntu site and download and install Ubuntu 12.04, which is the latest Long Term Support release. Make sure that you download the appropriate architecture i.e., 32- or 64-bit. Of course you can also bring your notebook to the ICT servicedesk and ask them to install Ubuntu. If you want to keep using Windows next to Ubuntu the most easy way is to have a dual-boot system, i.e., during startup you can choose to boot either Ubuntu or Windows.
Most of your interaction with Ubuntu will be done through the terminal, the number-one way of interacting with Ubuntu using your keyboard. A terminal can be started as follows: Application -> Accessories -> Terminal, or by pressing ctrl-alt-t. It might be a good idea to drag the terminal icon in the menu to the Ubuntu panel, as you will be using it a lot.
Although the terminal commands may seem somewhat puzzling at first, you'll soon find out that the terminal is a nifty tool and allows for faster and more powerful access to all of Ubuntu's possibilities than the graphical interface and mouse. If you don't know your way around the terminal, have a look at this page.
A convenient tool to avoid having a large amount of terminals is Terminator, so you can have multiple terminals in one window. To make Terminator start up with some screen setup:
- 1. Open “Terminator”
- 2. Make the set-up to be saved: some split ups
- a. Right click
- b. Choose “split horizontally” or “split vertically”
- c. Continue the previous step, until you are happy
- 3. Right click
- 4. Choose “preferences”
- 5. Pick tab “layout”
- 6. Click "add"
- 7. Enter a name (= <your chosen name>)
- 8. Press "enter"
- 9. Click "close"
- 10. Right click the button to open “Terminator”
- 11. Choose “properties”
- 12. Enter in “command” : “terminator -l <your chosen name>”
- 13. Click close
- 14. To test: open “Terminator”
In this project we will use the Robotic Operating System (ROS) which aids the testing and development of robot software. ROS provides a nice open-source framework for dealing with the communication between and management of different modules, and comes with a large amount of software that can be used out of the box, including device drivers, libraries, low- and high-level software, visualizers and more. More information about ROS and its goals can be found here. The ROS tutorial can be found here.
To install ROS Fuerte under Ubuntu 12.04, do the following:
- Add the ROS Debian source to your sources.list such that Ubuntu knows where to download ROS from. Open a terminal (Applications -> Accessories -> Terminal) and enter:
sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu precise main" > /etc/apt/sources.list.d/ros-latest.list'
- To be able to connect with the server, you need to add its public key to your keys:
wget http://packages.ros.org/ros.key -O - | sudo apt-key add -
- Make sure you have re-indexed the ROS.org server such that you get the latest changes:
sudo apt-get update
- Then, install a ROS desktop:
sudo apt-get install ros-fuerte-desktop
If you ran into problems, be sure to check the installation guide on the ROS website.
In this project, an SVN will be used for sharing and versioning the software within your group. Every group has its own space on the SVN, and an account which has only permissions for that particular part.
To set up the directory to where the code is checked out from the SVN, open a terminal and do the following:
- First, create a directory in your home directory in which you will put all ROS-related code, files and data:
- Then, go to that folder
cd ~/rosand check out your group folder from the SVN. For example, for group 1:
svn co http://svn2.wtb.tue.nl/repos/emc2012/groups/emc01You will be prompted for your account name and password.
- Furthermore, check out the general folder, which contains the robot simulator:
svn co http://svn2.wtb.tue.nl/repos/emc2012/general
You now have the latest version of all the code that is available on your computer. If you make any changes or improvements, you can save these changes on your disk without interacting with the SVN.
Once you are done with your work, or if you want to save intermediate results on the SVN, you can commit your changes by going to the folder where you have made the changes and then typing:
svn ci -m 'a description of the changes you made' file_I_want_to_commit.cpp
Please note that this will only upload the changes of files that are already on the SVN. If you want to add new files to the SVN you first have to add them by typing:
svn add file_I_want_to_add.cpp
You can add a folder recursively (with all files included in the folder) by typing:
svn add folder_I_want_to_add
Note that after adding you still have to commit your changes in order to store them on the SVN. You can delete files on the same way by typing delete rather then add.
Note: make sure you do not add auto-generated files, such as executables, to your SVN.
So far we've installed ROS and created a local copy of the SVN. However, before you can start working, you need to do some additional set-ups to make sure Ubuntu knows where to find all ROS-related packages, scripts, etc. More specifically, every time you start up a terminal, the correct environment variables need to be set. The file .bashrc in your home directory is your friend: it's a script which runs every time a a new terminal is opened. We basically need to add some lines to this file, so open the file with a text editor:
Append the following text to the end of the file:
This will set-up all ROS-related scripts etc. every time you open a terminal. Furthermore, ROS needs to known where your software is located. Therefore, also add the following command to ~/.bashrc:
That's it. Next time you open a terminal, .bashrc is executed, which will in turn execute the script and set the path specified above. Since the script only runs when a new terminal is opened, the changes are not active in your current terminal. If you want to see it working directly without starting a new terminal, explicitly source .bashrc from the terminal:
To see whether it worked, try one of commands that are now at your disposal. For example, change your directory to the roscpp package:
To keep the code in your packages clear and manageable, it is advised to use the editor Eclipse, an Integrated Development Environment (IDE) which is widely used for Java, C, C++ and many more languages. This section explains how it can be configured to be easily used with ROS packages.
To install Eclipse, do the following:
- Go to the Eclipse download site
- Find Eclipse IDE for C/C++ Developers and select the appropriate version on the right (32-Bit or 64-Bit Linux).
- Extract Eclipse into a folder of your choice
- You can create a launcher to Eclipse to your panel by alt + right clicking the panel, choosing 'Add to panel' and selecting 'Custom Application Launcher'. Then browse to the Eclipse executable, and enter a name. If you want you can add the Eclipse icon by clicking the image on the left and browsing to the icon in the Eclipse folder.
Now, to make sure your package can be viewed properly in Eclipse, do the following:
- Create a custom package in your ~/ros directory with optional dependencies:
roscreate-pkg <package-name> [dependencies...]
- Enter in a terminal:
roscd <package name>
- Open Eclipse
- You will be prompted to select a path for the workspace. The default (/home/YOUR_NAME/workspace) is fine here. This folder will not contain the software (that is stored in ~/ros), but simply pointers to the software and some administration files for Eclipse.
- Go to “file” → “Import”
- Click “General”
- Then “Existing Projects into Workspace”
- Click “next”
- Browse for the package
All environment settings should be set automatically. You can build the package using ctrl-b. Note that you have to remake the eclipse-project in your package every time you change the manifest or if you switch to a new version of ROS. If you're having trouble or want to know more about the possibilities of using eclipse with ROS, check the ROS wiki.