# pacman -yS tiacx # modprobe acx
Firmware gets installed automatically, as the tiacx-firmware package is a dependency for the tiacx package. The module will automatically be loaded on boot.
Now you need to edit your /etc/rc.conf file to add the new device.. My rc.conf file looks like this: <pre> wlan0="dhcp" wlan_wlan0="wlan0 ap 00:90:D0:F3:FC:52 key 21533b6820317a7e635d797e5b channel 11" WLAN_INTERFACES=(wlan0) INTERFACES=(lo wlan0) </pre> Officially the wlan_wlan0 and WLAN_INTERFACES options should be placed in /etc/conf.d/wireless, but since that file sources our rc.conf, we can also place it in there..
Basically the wlan_wlan0 line is executed using iwconfig, so you can execute
# man iwconfig
if you need more info about that. the wlan0="dhcp" line is standard archlinux, and will be executed using ifconfig, more info about it on the ArchWiki