Setting Up Jackal’s Network

Jackal is equipped with a combination Wifi + Bluetooth wireless module. On currently-shipping units, this is an Intel Centrino Advanced-N 6235. If this is your first unboxing, ensure that Jackal’s wireless antennas are firmly screwed on to the chassis.

First Connection

By default, Jackal’s wireless is in client mode, looking for the wireless network at the Clearpath factory. In order to set it up to connect to your own network, you’ll have to open up the chassis and connect a network cable to the PC’s STATIC port. The other end of this cable should be connected to your laptop, and you should give yourself an IP address in the 192.168.131.x space, such as 192.168.131.50. Then, make the connection to Jackal’s default static IP:

ssh administrator@192.168.131.1

The default password is clearpath. You should now be logged into Jackal as the administrator user.

Connecting to Wifi Access Point

Jackal’s standard wireless network manager is wicd. To connect to an access point in your lab, run:

wicd-curses

You should see a browsable list of networks which the robot has detected. Use arrow keys to select the one you would like to connect to, and then press the right arrow to configure it. You can enter your network’s password near the bottom of the page, and note that you must select the correct encryption scheme; most modern networks use WPA1/2 Passphrase, so if that’s you, make sure that option is selected. You also likely want to select the option to automatically reconnect to this network, so that Jackal will be there for you on your wireless automatically in the future.

When you’re finished, press F10 to save, and then C to connect.

Wicd will tell you in the footer what IP address it was given by your lab’s access point, so you can now log out, remove the network cable, and reconnect over wireless. When you’ve confirmed that all this is working as expected, close up Jackal’s chassis.

Remote ROS Connection

To use ROS desktop tools, you’ll need your computer to be able to connect to Jackal’s ROS master. This can be a tricky process, but we’ve tried to make it as simple as possible.

In order for the ROS tools on your computer to talk to Jackal, they need to know two things:

• How to find the ROS master, which is set in the ROS_MASTER_URI environment variable, and
• How processes on the other computer can find your computer, which is the ROS_IP environment variable.

The suggested pattern is to create a file in your home directory called remote-jackal.sh with the following contents:

export ROS_MASTER_URI=http://cpr-jackal-0001:11311  # Jackal's hostname
export ROS_IP=10.25.0.102                           # Your laptop's wireless IP address

If your network doesn’t already resolve Jackal’s hostname to its wireless IP address, you may need to add a corresponding line to your computer’s /etc/hosts file:

10.25.0.101 cpr-jackal-0001

Then, when you’re ready to communicate remotely with Jackal, you can source that script like so, thus defining those two key environment variables in the present context.

source remote-jackal.sh

Now, when you run commands like rostopic list, rostopic echo, rosnode list, and others, the output you see should reflect the activity on Jackal’s ROS master, rather than on your own machine. Once you’ve verified the basics (list, echo) from the prompt, try launching some of the standard visual ROS tools:

roslaunch jackal_viz view_robot.launch
rosrun rqt_robot_monitor rqt_robot_monitor
rosrun rqt_console rqt_console

If there are particular rqt widgets you find yourself using a lot, you may find it an advantage to dock them together and then export this configuration as the default RQT perspective. Then, to bring up your standard GUI, you can simply run:

rqt

Advanced: Hosting a Wifi Access Point

The default network manager (wicd) only supports joining existing networks. It does not support creating its own wireless AP. However, there is experimental support in Jackal for a modern network manager called connman, which does.

Warning

You are unlikely to damage your hardware by switching Jackal from wicd to connman, but it’s possible you could end up with a platform which will need to be reflashed back to the factory state in order to be usable. If you’re comfortable with this and have backed up your data, proceed.

Add the PPA which makes up-to-date connman releases available to Ubuntu 14.04, and install connman.

sudo add-apt-repository ppa:mikepurvis/network
sudo apt-get update
sudo apt-get install connman

Now edit the upstart job file in /etc/init/connman.conf. Suggested configuration:

description "Connection Manager"

start on started dbus
stop on stopping dbus

console log
respawn

exec connmand --nobacktrace -n -c /etc/connman/main.conf -I eth1 -I hci0

And edit connman’s general configuration in /etc/connman/main.conf. Suggested:

[General]
TetheringTechnologies = wifi
PersistentTetheringMode = true

Now, use the connmanctl command-line interface to set up an AP, which connman calls “tethering” mode:

$ connmanctl
connmanctl> enable wifi
connmanctl> tether wifi on Jackal clearpath

If you want to use connman to connect to another AP rather than host:

$ connmanctl
connmanctl> tether wifi off
connmanctl> agent on
connmanctl> scan wifi
connmanctl> services
connmanctl> connect wifi_12345_67890_managed_psk

Use as the argument to connect one of the services listed in the services output. You will be interrogated for the network’s password, which is then cached in /var/lib/connman/.