Reference

This page contains various bits of extra material. This is mostly meant as a reference for the maintainers of the robots.

Backup and restore the SD-card

To be more flexible, we will back up the root and the boot partition separately.

1. Identify the location of the SD-card. Partition names will be PI_BOOT and PI_ROOT.

df -h

2. Backup up boot (* the name you found in step 1. e.g., mmcblk0p1 ). This should only take a short time (seconds). This will make boot.iso file in home folder. 'if' is input file, 'of' is output file, the order is NOT important.

sudo dd if=/dev/sd*1 of=~/boot.iso

3. Backup up root (* the name you found in step 1, e.g. mmcblk0p2 ). Takes up to 30min and will make root.iso in home folder. No feedback will be shown while the backup is happening, so don't interrupt it.

sudo dd if=/dev/sd*2 of=~/root.iso

4. Copy to clean SD. Small preparation in Gparted (gui for partition manager). Make a first partition on 100MB formatted to fat16. Rest is ext4. Make sure the size of your root.iso is smaller than this second partition. If this is not the case, use Gparted to shrink the original SD cart, and repeat step 3. Copying root.iso can take up to 30min.

sudo dd of=/dev/dev/sd*1 if=~boot.iso bs=4M
sudo dd of=/dev/dev/sd*2 if=~root.iso bs=4M

If your SD-card doesn't work (kernel panic), don’t use the bs=4M, but copying will be much (up to one hour).

Modifications

A number of modifications have been made to the platform to make it more accessible to students:

1. The raspberry pi functions as an access point. The previous configuration was to have a central access point or to connect the robots to the KU leuven network. Due to slow and unstable connections, students now log onto the robots themselves. The robots show up as a wireless connection (like eduroam or campusroam). Each robot has a unique name for its access point (this can be changed in the file /etc/hostapd/hostapd.conf). When connected to the robot wifi, an SSH connection can be establised on the IP address '192.168.42.1'. The computer itself will be assigned the IP address '192.168.42.4'. This was achieved by using this guide and this guide.

2. The /etc/rc.local file was edited so that on boot:

   1. The access point services are started on boot. If this does not function correctly, the following commands have to be executed manually:

      sudo ifup wlan0
      sudo service dnsmasq start

   2. A git pull is initiated for the full repository (in the root directory) and the core turtlebot3_GT (in the catkin workspace) repository

3. The turtlebot3_GT_bringup.launch file is started on boot with the robot_upstart package. Installation is easiest with package manager: sudo apt-get install ros-kinetic-robot-upstart

4. The raspberrypi boots without graphical interface by default. This can be changes with the raspi-config command. To start the graphical interface, use the command startx.

Aliases

• eb='gedit ~/.bashrc'
• nb='nano ~/.bashrc'
• sb='source ~/.bashrc'
• gs='git status'
• gp='git pull'
• cw='cd ~/catkin_ws'
• cs='cd ~/catkin_ws/src'
• cm='cd ~/catkin_ws && catkin_make'
• teleop='roslaunch turtlebot3_teleop turtlebot3_teleop_key.launch'
• bringup='roslaunch turtlebot3_bringup turtlebot3_robot.launch'

Removed packages

These were removed by the script: 'remove_packages.sh' (the user has to accept removal for each package)

• libreoffice

• minecraftpi

• scratch

• pluma

• shotwell

• thunderbird

• hexchat

• pidgin

• youtube-dl

• mate-dictionary

• atril

• sonic-pi

• brasero

• cheese

• qjackctl

• rhythmbox

• vlc*

• sense_*

Other

Complete documentation by the manufacturer

Complete assembly manual