Overo Wifi
Overo Air, Fire, FE, AirSTORM, FireSTORM and IronSTORM COMs have a 802.11(g) wireless module "on board". This page gives some details about the hardware and software configuration for the wifi module on these COMs.
Contents
Hardware
This section gives some infos about various hardware related topics regarding Overo and Overo STORM Wifi.
Module
The wifi solution is based on an Wi2Wi chip based on Marvell's industry leading 88W8686 which brings 802.11(b/g) wifi.
MMC
Overo's WiFi port connected to MMC port 2 in 4 bit configuration.
Connector and Antenna
For 802.11b/g (Wifi) to work on an Overo Air COM or Overo Fire COM, a u.fl antenna must be connected to J2 on Overo Air or Fire COMs. The location of J2 is shown here.
Note: J3 is the antenna location when using BlueTooth. J3 also takes a u.fl antenna.
Note that two (2) u.fl antennae come with each Overo Fire COM and with each Overo Air COM.
Software
Official Overo pre-built Linux images or developer images contain already support for Overo Wifi. However, wifi configuration depending on your local wifi environment still has to be done.
There is also a thin-firmware driver and firmware that permit you to utilize the mac80211 drives in the Linux kernel. This is useful if you want to experiment with running an AP, 802.11s mesh, or other types of experiments on your Overo.
Boot messages
At Overo boot, you should get something like
... libertas_sdio: Libertas SDIO driver libertas_sdio: Copyright Pierre Ossman libertas_sdio mmc1:0001:1: firmware: requesting sd8686_helper.bin libertas_sdio mmc1:0001:1: firmware: requesting sd8686.bin libertas: 00:19:88:05:b5:31, fw 9.70.3p24, cap 0x00000303 libertas: PREP_CMD: command 0x00a3 failed: 2 libertas: PREP_CMD: command 0x00a3 failed: 2 libertas: eth0: Marvell WLAN 802.11 adapter ...
Note: The two “command 0×00a3 failed” messages are harmless, and have to do with features that are not supported.
Test
For test of basic functionality, do the following at command line (after log in as root / no password):
root@overo:~# iwconfig wlan0 essid any root@overo:~# ifconfig wlan0 up root@overo:~# iwlist wlan0 scan
what should list the wifi's visible, then.
Unencypted wifi
Some default builds do not enable any Wifi. You may need to edit /etc/network/interfaces to include a section which looks like:
allow-hotplug wlan0
auto wlan0
iface wlan0 inet dhcp
pre-up /sbin/iwconfig wlan0 essid any
wireless_mode managed
The problem is this setup is not reliable! we're waiting for a solution.
WEP encryption
- Edit /etc/network/interfaces to have only for wlan0 (don't touch the other entries):
iwconfig wlan0 essid "My Wireless Network" iwconfig wlan0 key my-hex-key ifdown wlan0 ifup wlan0
WPA encryption
- Edit /etc/network/interfaces to have only for wlan0 (don't touch the other entries):
allow-hotplug wlan0
iface wlan0 inet dhcp
pre-up wpa_supplicant -Dwext -iwlan0 -c/etc/wpa_supplicant.conf -B
down killall wpa_supplicant
There is an error in the current /etc/network/interfaces as of 2011-09-25. The pre-up line reads:
pre-up wpa_supplicant -Dmarvell -iwlan0 -c/etc/wpa_supplicant.conf -Bw
The "-Bw" causes a usage message to be dumpted to the screen. Make sure it is just "-B". The -Dmarvell option will yield the message "Unsupported driver 'marvell'. Change it to "-Dwext" as shown above.
My /etc/network/interfaces came this way from the factory, and was also that way in my build from the latest git.
- Create /etc/wpa_supplicant.conf containing:
ctrl_interface=/var/run/wpa_supplicant
ctrl_interface_group=0
eapol_version=1
ap_scan=1
fast_reauth=1
network={
ssid="add-your-ascii-ssid"
proto=WPA2 # try WPA RSN if you WPA2 fails
key_mgmt=WPA-PSK
pairwise=CCMP TKIP
group=CCMP TKIP
scan_ssid=1
psk="add-your-ascii-passphrase"
priority=10
}
Connect to network
To connect to the wireless network when the configuration is done, do the following:
- Take down the wireless network (it might already be down, but try to be sure):
# ifdown wlan0
- Then, bring it up again:
# ifup wlan0
Issues
Many users have reported issues with wifi data throughput being limited to about 100kB/second. It is theorized this is due to lack of SDIO IRQ support in the OMAP3 MMC driver. A patch is being investigated which reportedly achieves 13Mbps.
Additionally, the driver does not support power management at present. The use of iwconfig power commands such as the following will fail:
iwconfig wlan0 power on
Therefore, the wifi module always consumes close to 1 Watt of power when turned on.
NetworkManager
If NetworkManager is installed, this would probably not work. Check if it is installed by:
# opkg list_installed | grep networkmanager
If it is installed, remove it:
# opkg remove networkmanager
This if NetworkManager is not needed. NetworkManager uses a different configuration.
