Autonomous Robotics: Lab 1

Turtlebot Teleoperation

Log into the Turtlebot and bring up a wireless connection. You will need to change the Authentication setting to "Protected EAP (PEAP)". When the box appears complaining that "No Certificate Authority certificate chosen", click "Ignore".
Once the wireless connection is established, double click the launcher labeled "Init Ros Workspace". This launcher accomplishes two things: it checks out your code from the subversion server and it runs a couple of setup instructions for ROS:
```
rosdep update
rospack profile
```

Since you don't yet have a subversion repository, we are only interested in these two commands. You can just let the checkout step fail.

Make sure the Turtlebot is turned on and connected to your netbook over the USB cable.

Open a terminal and type:

roslaunch turtlebot_bringup minimal.launch

If all goes well, the terminal should fill with notification messages and the robot should make a pleasant electronic startup sound.

Open up a new tab in your terminal and type:

roslaunch turtlebot_teleop keyboard_teleop.launch

Once the instructions appear you should be able to drive your Turtlebot from the keyboard.

True Teleoperation

Kill the teleop process by pressing Ctrl-C in that terminal tab. (This is the universal off switch for ROS processes.)

Figure out the IP address of your netbook. You can do this by typing ifconfig into a terminal window. You should see something like:

eth0      Link encap:Ethernet  HWaddr b8:88:e3:46:b4:db  
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)
          Interrupt:18 

eth1      Link encap:Ethernet  HWaddr e0:06:e6:16:ed:bd  
          inet addr:134.126.83.227  Bcast:134.126.87.255  Mask:255.255.248.0
          inet6 addr: fe80::e206:e6ff:fe16:edbd/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:84410 errors:0 dropped:0 overruns:0 frame:5372523
          TX packets:5590 errors:16 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:12745516 (12.7 MB)  TX bytes:856694 (856.6 KB)
          Interrupt:17 

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:311754 errors:0 dropped:0 overruns:0 frame:0
          TX packets:311754 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:93860812 (93.8 MB)  TX bytes:93860812 (93.8 MB)

You are looking for an "inet addr" field that looks like an IP address. In this case it is 134.126.83.227. Note that IP address for later use.

Log into one of the lab machines against the wall.

Now ssh into your Turtlebot:

ssh -X robot@134.126.83.227

Relaunch teleop and drive your robot around.

ROS Nodes and Topics

Work through the ROS Tutorials on nodes and topics.

Extra

If you have extra time, test your new found knowledge of nodes and topics by switching on the Turtlebot's LED's from the command line. You will need publish an appropriate message to the appropriate topic using the rostopic command.