Network

Default Network configuration

In the Ubuntu 14.04 installation delivered with the Odroid computer, a default network configuration has been defined for the car, as shown in the table below.

Ethernet IP address               [192.168.1.199]  
Ethernet netmask                  [255.255.255.0]
Ethernet broadcast                [192.168.1.255]
Ethernet gateway                  [192.168.1.1]
Wireless network name(SSID)       [ROS]
Wireless password                 [elfmeter]
Encryption (wep, wpa)             [wpa]
Wireless IP(enter dhcp for DHCP)  [192.168.43.102]
Wireless netmask                  [255.255.255.0]
Wireless broadcast                [192.168.43.255]
Wireless gateway                  [192.168.43.1] 

You can check the network configuration with the command:

$ ifconfig

How to change the Network Configuration

The network configuration is contained in the files:“/etc/network/interfaces” and “etc/wpa_supplicant.conf” files. To define a new configuration modify those files. For example, the wireless IP address is contained in the first file, which can be opened in the Odroid with:

 $ vim /etc/network/interfaces

If you want to change the default wireless IP address from 192.168.43.102 to the new address (192.168.43.103) the new line should read:

iface wlan0 inet static
   address 192.168.43.103

And change the ROS_HOSTNAME and ROS_MASTER_URI in .bashrc and autostart.sh files:

export ROS_HOSTNAME=192.168.43.103
export ROS_MASTER_URI=http://192.168.43.103:11311

Save the file and reset the Odroid. From now on you can connect to the car using the Android APP and the new wireless IP address.

Save the file and reset the Odroid. From now on you can connect to the car using the Android APP and the new wireless IP address. To change the wireless hotspot name, open the second file.

  $ vim /etc/wpa_supplicant.conf

and change the network settings. The current settings are:

  network={
    ssid="ROS"
    key_mgmt=WPA-PSK
    psk="elfmeter"
  }

Share wireless Internet connection through Ethernet

The preferred mode of transferring files from the Internet to the Odroid should be by downloading them in your own computer and then copying to the Odroid. That saves effort. However, if for some reason you want to connect the Odroid to the Internet, you can share your laptop’s Internet wireless access using the Ubuntu preferred method, as explained in the Ubuntu Wiki.Here we just mention the basics.

You can share the WiFi Internet access of your computer with the Odroid (which we assume is connected with an Ethernet cable to your computer). You need to redefine the eth0 configuration contained in the “/etc/network/interfaces” file.

 $vim /etc/network/interfaces

In the following example your computer will become the gateway and it gets assigned the address 10.42.0.1 and the Odroid gets assigned the address 10.42.0.10:

 auto eth0
    iface eth0 inet static
    address 10.42.0.10
    netmask 255.255.255.0
    broadcast 10.42.0.255
    gateway 10.42.0.1 

Reset the Odroid and connect from your computer with the new Ethernet IP address:

   $ ssh root@10.42.0.10
   $ Password: elfmeter

Then reset the dhclient eth0 in the Odroid

 $ dhclient -r eth0
 $ dhclient  eth0

Check the internet connection with a ping from the Odroid:

 $ ping google.com

Be aware than once you redefine the network address of the Odroid, the default addresses contained will have changed.