On the Reference Images for Yocto Project, the connman package provides connectivity management.

Automatic (GUI)

The connections can be configured by starting the configuration program connman-properties or by starting the taskbar applet connman-applet.

Interactively

Note: On the Colibri iMX6ULL make sure to connect to the mlan0 Wi-Fi interface which may be distinguished based on their MAC addresses.

root@colibri-imx6ull:~# connmanctl 
Error getting VPN connections: The name net.connman.vpn was not provided by any
connmanctl> enable wifi
[  426.104116] IPv6: ADDRCONF(NETDEV_UP): mlan0: link is not ready
[  426.145123] IPv6: ADDRCONF(NETDEV_UP): uap0: link is not ready
Enabled wifi
connmanctl> scan wifi
[  452.706815] ieee80211 phy0: mwifiex_cfg80211_sched_scan_start : Invalid Sched_scan parameters
Scan completed for wifi
connmanctl> agent on
Agent registered
connmanctl> services
    testnet             wifi_0019885e10de_666167776c616e32_managed_psk
    testnet             wifi_0019885e11de_666167776c616e32_managed_psk
connmanctl> connect wifi_0019885e10de_666167776c616e32_managed_psk
Agent RequestInput wifi_0019885e10de_666167776c616e32_managed_psk
  Passphrase = [ Type=psk, Requirement=mandatory ]
Passphrase? testpw
connmanctl> [  637.111283] mwifiex_sdio mmc1:0001:1: info: trying to associate to 'testnet' bssid 44:d9:e7:fa:cf:d5
[  637.137213] mwifiex_sdio mmc1:0001:1: info: associated to bssid 44:d9:e7:fa:cf:d5 successfully
[  637.194021] IPv6: ADDRCONF(NETDEV_CHANGE): mlan0: link becomes ready
[  676.632838] ieee80211 phy0: mwifiex_cfg80211_sched_scan_start : Invalid Sched_scan parameters
Connected wifi_0019885e10de_666167776c616e32_managed_psk
connmanctl> quit

Manual

Our latest V2.x images also include a command-line configuration tool called connmanctl:

https://gist.github.com/kylemanna/6930087

As follows how to connect to a WPA PSK enabled Wi-Fi using an LM006 USB stick, or the Colibri iMX6ULL 512MB WB on-module Wi2Wi WM828CC6 adapter.

First plug in the Wi-Fi USB stick (LM006 only):

[   55.779953] usb 3-1: new high speed USB device number 3 using tegra-ehci
[   55.971825] usb 3-1: New USB device found, idVendor=0bda, idProduct=8176
[   55.978538] usb 3-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[   55.985743] usb 3-1: Product: 802.11n WLAN Adapter
[   55.990587] usb 3-1: Manufacturer: Realtek
[   55.994688] usb 3-1: SerialNumber: 00e04c000001
[   56.151090] rtl8192cu: MAC address: 5c:f3:70:24:97:e5
[   56.156167] rtl8192cu: Board Type 0
[   56.171585] rtlwifi: rx_max_size 15360, rx_urb_num 8, in_ep 1

Then enable the Wi-Fi technology layer:

root@colibri-t30:~# connmanctl enable wifi
[  531.793311] rtl8192cu: MAC auto ON okay!
[  531.857315] rtl8192cu: Tx queue select: 0x05
[  531.863386] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cufw.bin
[  532.376983] ADDRCONF(NETDEV_UP): wlan0: link is not ready
Enabled wifi

And scan for available networks:

root@colibri-t30:~# connmanctl scan wifi
Scan completed for wifi

Now show what the above actually found:

root@colibri-t30:~# connmanctl services
*AR Wired                { ethernet_00142d486cef_cable }
<SSID>               { wifi_<HASH>_managed_psk }

Finally, adjust the security aka WPA PSK configuration:

root@colibri_t30:~# vi /var/lib/connman/<SSID>-psk.config
[service_wifi_<HASH>_managed_psk]
Type = wifi
Name = <SSID>
Passphrase = <PASSPHRASE>

Last but not least attempt to connect:

root@colibri_t30:~# connmanctl connect wifi_<HASH>_managed_psk
[ 1165.219739] ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
Connected

If you still have wired Ethernet connected make sure to disconnect the cable in order for Wi-Fi to take over:

root@colibri-t30:~# [  653.968178] eth0: ax88772b - Link status is: 0
[  654.026020] ADDRCONF(NETDEV_UP): eth0: link is not ready

Configuring Wi-Fi with static IP address

Configuring Wi-Fi with a static IP address can be done using the connman-applet with a graphical user interface. If one does not have a GUI, the process must be done via the command-line interface.

When a WPA PSK configuration file is created, connman automatically configures Wi-Fi to use DHCP and does not allow manual changes to the IP address as it would for an Ethernet connection using connmanctl.

If the following file was created before, it needs to be deleted, as it conflicts with a new file that will be created:

/var/lib/connman/<SSID>-psk.config

First, create the following directory (where <HASH> is the hash identifier assigned to the device by connman):

mkdir /var/lib/connman/wifi_<HASH>_managed_psk

Inside the directory, create a file named “settings”:

vi /var/lib/connman/wifi_<HASH>_managed_psk/settings

The file should contain the following:

[wifi_<HASH>_managed_psk]
Name=<SSID>                        ← Name of your network
SSID=544f52414445585f4252          ← Name of your network in hexadecimal format
Favorite=true
IPv4.method=manual                 ← Method to be used (in our case manual IP)
IPv4.netmask_prefixlen=24
IPv4.local_address=192.168.0.133   ← Desired IP address
IPv4.gateway=192.168.0.1
Passphrase=<PASS>                  ← Wi-Fi network password
AutoConnect=true

In this next step, we have three options, one can use what is best suited to the application:

• reboot the module;
• disconnect and reconnect the Wi-Fi module (if it was already connected);
• restart the USB bus port with the following commands:

echo '1-1' > /sys/bus/usb/drivers/usb/unbind
echo '1-1' > /sys/bus/usb/drivers/usb/bind

Now enable the Wi-Fi technology layer:

connmanctl enable wifi

Finally, simply connect to the network:

connmanctl connect wifi_<HASH>_managed_psk

On images V1.x the following brings up the connection from the command line:

ifconfig wlan0 up
iwlist wlan0 scanning
wpa_supplicant -Dwext -iwlan0 -c/etc/wpa_supplicant.conf
#  -dd for debugging
#  -B for background daemon

To do WEP, WPA, or WPA2 just edit /etc/wpa_supplicant.conf and add the information about your wireless network infrastructure.

If you erroneously specify proto=WPA but do have a WPA2 infrastructure, wpa_supplicant returns the following error message if running with debugging (-dd) enabled:

wlan0:    skip - no WPA/RSN proto match

With all the steps concluded, the module should be connected with the chosen static IP address and it is now possible to freely change the IP address using connmanctl.