WiFi Network

We use the following network architecture:

Robot Wifi AP <- 1 -> Groundstation Bullet <- 2 -> Groundstation Laptop

Robot wifi AP

We use WiFi in AP mode in the robot. This makes the connection more stable from the robot point of view. By using the robot in AP mode, the WiFi connection is always available (it doesn't drop if the robot goes out of range).

We decide to run the ROS Master in this connection.

The configuration can be made using NetworkManager GUI or TUI.

sudo nmtui

Select Edit a connection > Add > Wi-Fi. Then:

• Use Hotspot as profile name.
• Be sure that the device you are using is the right one. For the NUC, it looks like wlp0s20f0.
• The SSID has to be falcon-dcist-robotName. For instance falcon-dcist-titan.
• The mode has to be Access Point.
• Set the Channel to Automatic
• Configure the Security to WPA & WPA2 Personal
• Use the classic MRSL password.
• IPv4 configuration has to be Shared.
• IPv6 configuration has to be Ignore.
• Check Automatically connect and Available to all users

After you finish the configuration, you should be able to connect to the robot using your computer's Wi-Fi connection. The IP of the robot is usually 10.42.0.1, but you may check this with the ip addr command. For instance:

dcist@rhea:~$ sudo ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eno1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 1c:69:7a:6d:2d:4a brd ff:ff:ff:ff:ff:ff
    inet 192.168.100.1/24 brd 192.168.100.255 scope global noprefixroute eno1
       valid_lft forever preferred_lft forever
    inet6 fe80::1e69:7aff:fe6d:2d4a/64 scope link
       valid_lft forever preferred_lft forever
3: wlp0s20f3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether f8:ac:65:d8:d2:0e brd ff:ff:ff:ff:ff:ff
    inet 10.42.0.1/24 brd 10.42.0.255 scope global noprefixroute wlp0s20f3
       valid_lft forever preferred_lft forever
    inet6 fe80::faac:65ff:fed8:d20e/64 scope link
       valid_lft forever preferred_lft forever

Groundstation receiver

Bullet configuration

The groundstation Bullet receiver will communicate with the robot AP. We will connect to the Bullet using an Ethernet cable. This solution works better than using your laptop's Wi-Fi to connect directly to the robot, specially outdoors.

1. Reset the Bullet to factory default (BulletM2 Manual).
2. Connect it to your computer. Configure a static IP for your computer in the 192.168.1.0/24 network.
3. You can now connect to the Bullet using a web browser. The default IP is 192.168.1.20.
4. Connect to the robot:
   1. Go to the Wireless tab and choose Station.
   2. Select the SSID to the robot SSID. Lock to AP.
   3. Set the robot network password (classic MRSL password).
   4. Apply the changes.
5. Once the bullet connects to the robot, it's IP will change. Remove the static IP you set on step 2, and request a new IP with DHCP. You should receive an IP in the range 10.42.0.0/24.
6. Check that you can connect to the robot.