dehunt911
Posts: 3
Joined: Sun Feb 10, 2013 10:23 am

Unable to configure EDIMAX EW-7811Un to work on Channels 12

Tue Apr 16, 2013 6:00 pm

My EW-7811UN works fine on channels 1-11 on the 2.4 GHz band. It does not work on channels 12 or 13 as a wireless workstation.

I was wondering if anybody had experience of this and could help me with the configuration or installing an appropriate driver.

I am on the following update of Raspbian:
Linux raspberrypi 3.6.11+ #371 PREEMPT Thu Feb 7 16:31:35 GMT 2013 armv6l

The EW-7811UN is one I bought from Amazon UK and it says on the packaging that it is for the GB as well as a number of other European countries – Serial number is *EW7811UN2ACE11487*.

There are a few interrogations below.

When I key in iwlist wlan0 frequency then Channel 13 is listed twice with the same frequency – this is the correct frequency for Channel 13 but there is no frequency for Channel 12 – 2.467 GHz. In addition I cannot connect via Channel 13 to my router when I set my router to run on Channel 13 on the 2.4 GHz band.

Also I cannot configure the frequency using iwconfig.

My router is a ZyXEL NBG5615 which is capable of wireless operation on 2.4 GHz and 5.0 GHz bands. I only need the 2.4 GHz b/g/n band but I need it to work on all 13 channels as does my router.

I can force the router to a specific channel ( I have set it to Channel 1) but I would prefer that the EW-7811UN work as it ought to work here in Europe on all 13 Channels.

What do I need to do?

I have downloaded rtl8192cu_linux_v2.0.939.20100726.tar.gz from EDIMAX support pages and have unpacked it but there are no instructions on how to install anything contained within the file.

Here is what I get:

[email protected]:~# iwlist wlan0 frequency
wlan0 13 channels in total; available frequencies :
Channel 01 : 2.412 GHz
Channel 02 : 2.417 GHz
Channel 03 : 2.422 GHz
Channel 04 : 2.427 GHz
Channel 05 : 2.432 GHz
Channel 06 : 2.437 GHz
Channel 07 : 2.442 GHz
Channel 08 : 2.447 GHz
Channel 09 : 2.452 GHz
Channel 10 : 2.457 GHz
Channel 11 : 2.462 GHz
Channel 13 : 2.472 GHz
Channel 13 : 2.472 GHz
Current Frequency:2.412 GHz (Channel 1)

[email protected]:~# iwconfig wlan0 channel 12 freq 2.467G commit
Error for wireless request "Commit changes" (8B00) :
SET failed on device wlan0 ; Operation not supported.

[email protected]:~# iwconfig wlan0 channel 13 freq 2.472G commit
Error for wireless request "Commit changes" (8B00) :
SET failed on device wlan0 ; Operation not supported.


[email protected]:/etc/wpa_supplicant# cat wpa_supplicant.conf
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1

network={
ssid="myssid01"
psk="bbbbbbbb"
proto=WPA
key_mgmt=WPA-PSK
pairwise=TKIP
auth_alg=OPEN
}

# Added the following line – no effect
country=GB

dehunt911
Posts: 3
Joined: Sun Feb 10, 2013 10:23 am

EDIMAX EW-7811Un now works on Channels 12 & 13

Wed Apr 17, 2013 8:11 pm

SOLVED
Thanks to MrEngman
His profile is at: http://www.raspberrypi.org/phpBB3/membe ... le&u=10221

I took the following steps:

1) Logged onto RPis as pi/raspberry using Putty
2) sudo passwd root (set a root password)
3) Logged off and logged back on as root using Putty
4) Navigated to https://github.com/Hexxeh/rpi-update on my PC and performed the following steps:
4a) apt-get update
Updates wheezy to: Linux raspberrypi 3.6.11+ #408 PREEMPT Wed Apr 10 20:33:39 BST 2013 armv6l
You will need to be at close to this level or the following may not install

4b) apt-get install git-core
4c) wget http://goo.gl/1BOfJ -O /usr/bin/rpi-update && sudo chmod +x /usr/bin/rpi-update
4d) rpi-update
4e) Reboot using shutdown -r 0

According to MrEngman this installs a newer version of the rtl8192cu driver.

Results:

[email protected]:~# iwlist wlan0 frequency
wlan0 13 channels in total; available frequencies :
Channel 01 : 2.412 GHz
Channel 02 : 2.417 GHz
Channel 03 : 2.422 GHz
Channel 04 : 2.427 GHz
Channel 05 : 2.432 GHz
Channel 06 : 2.437 GHz
Channel 07 : 2.442 GHz
Channel 08 : 2.447 GHz
Channel 09 : 2.452 GHz
Channel 10 : 2.457 GHz
Channel 11 : 2.462 GHz
Channel 12 : 2.467 GHz
Channel 13 : 2.472 GHz
Current Frequency:2.472 GHz (Channel 13)

And all channels appear to work with the EW-7811Un on my Raspberry Pi.

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