fwm
Posts: 6
Joined: Thu May 02, 2013 2:59 pm

Realtek wifi 8188CUS doesn't "just work"

Thu Aug 08, 2013 7:14 pm

I am new to linux and Raspberry Pi's, but I am good at following directions. US application, if that makes any difference.
I have an Ethernet RPi running Apache2 serving my 1.2G web files, following instructions I found on here.

I bought 4 more Pi's and 3 Realtek wifi usb dongles to play with.
I loaded the latest version of 'wheezy' 07-something-2013, configured for US 105 key board, expanded OS on SD card, rebooted, updated, upgraded, halted, powered down, installed the usb wifi and repowered.

Did an lsusb and saw that it is aware of the realtec RTL8188CUS.

Did a startx and brought up the wifi config. Nothing. It showed 'wlan0' and nothing more. Scan button does nothing.
Tried to edit interfaces and wpa-supplicant files according to several matching sets of instructions I found on the net and nothing
Now the wifi confi in the desktop doesn't even show 'wlano'.

Home wifi is a 8011b/g/n, WPA password controlled with broadcast ssid. Already running on it are 3 Windows 7 laptops, 2 iPhone's, 1 iPad, 1 HP wireless printer, 1 iMac G4, 1 Windows 7 desktop and 1 Windows 2000 desktop. From any of these I can see my home wifi as well as 6 other local wifi's.

Don't see why this doesn't 'just work'. Help.

Same problem with all three usb wifi's and 3 of the new Pi's (didn't try the other two)

MrEngman
Posts: 4114
Joined: Fri Feb 03, 2012 2:17 pm
Location: Southampton, UK

Re: Realtek wifi 8188CUS doesn't "just work"

Thu Aug 08, 2013 9:38 pm

You can try setting it up manually. Take a look at http://www.fars-robotics.net/.


MrEngman
Simplicity is a prerequisite for reliability. Edsger W. Dijkstra

Please post ALL technical questions on the forum. Please Do Not send private messages.

fwm
Posts: 6
Joined: Thu May 02, 2013 2:59 pm

Re: Realtek wifi 8188CUS doesn't "just work"

Fri Aug 09, 2013 1:37 am

That is exactly what I did, several times, proofreading all statements, that removed the 'wlan0' from my wifi config on the desktop, with no good results being made. In one place I saw a reference to 'country code'. Is that a possibility?

Apache2 and php on RPi was easy. This just doesn't work.

fwm
Posts: 6
Joined: Thu May 02, 2013 2:59 pm

Re: Realtek wifi 8188CUS doesn't "just work"

Fri Aug 09, 2013 1:46 am

Forgot to mention, lsmod shows 8192cu loaded.

MrEngman
Posts: 4114
Joined: Fri Feb 03, 2012 2:17 pm
Location: Southampton, UK

Re: Realtek wifi 8188CUS doesn't "just work"

Fri Aug 09, 2013 9:25 am

There are a number of items that could cause problems. The favourite appears to be power supply issues. Another is whether the wifi access point transmits it's name or not. Adding a line scan_ssid=1 into the network section of /etc/wpa_supplicant/wpa_supplican.conf will allow connecting to access points with a hidden ssid. If you use a wireless keyboard/mouse there could be interference issues. Many people having problems appear to have got their's working by plugging the wifi directly in to one of the Pi's USB ports rather than using a hub. Although other's have found using a hub helped. Could be the hub being used caused problems for some.

Your wifi is detected and the driver is loaded. To be able to use the GUI the /etc/network/interfaces file needs leaving as the default when installed. So the wifi section should look like

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allow-hotplug wlan0
iface wlan0 inet manual
wpa-roam /etc/wpa_supplicant/wpa_supplicant.conf
iface default inet dhcp
and the default /etc/wpa_supplicant/wpa_supplicant.conf should initially look like

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ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
If you set it up to only use /etc/network/interfaces then I would not expect the GUI to work.

I have seen a strange problem when I had a wifi adaptor plugged into a hub. It was originally seen but then disappeared. Changing the wifi adaptor to a different port on the hub and it started working fine - really odd. But even stranger I moved it back to the original port it had been in and it continued to work. Never have figured out why.

Country code must be to do with the wireless channels used in different places round the world. You can check the channels used by the wifi with the command iwlist wlan0 channel and compare it with the ones your access point uses. How you configure it, however, I have no idea.

Just a few thoughs. Sorry not to be more helpful.


MrEngman
Simplicity is a prerequisite for reliability. Edsger W. Dijkstra

Please post ALL technical questions on the forum. Please Do Not send private messages.

fwm
Posts: 6
Joined: Thu May 02, 2013 2:59 pm

Re: Realtek wifi 8188CUS doesn't "just work"

Fri Aug 09, 2013 1:26 pm

I have made changes to the interfaces file to have ssid and pswd in it. No go
I have made changes to the wpa_supplicant file. No go.
I have made changes to both files. No go.

I have reload the SD card and started from scratch now at least 10 times following the most agreed upon tricks found (and several alternatives) on the internet. No go. I have swapped out three different, identical, brand new usb wifi's. Same results.

I do use wifi channel 11, as channel 1 has someones web cam on it, channel 3 has someones wireless headphones on it. Channel 6 has 6 local wifi's and a hotel from 13 miles away on it. But still, every new gadget I get sees my home network with no problems, except my 5 raspberry pi's with 4 different realtek wifi usb's. (I tried getting my first RPi on wifi, but had the same exact problems and gave up and connected it to my last ethernet port to run my web server)

As my router is in a room used by my wife's best friend and all ethernet ports on it are in use, if I can't get this to work the raspberry is useless for me. And I had hoped to do so many different things with them.

My access point does broadcast it's name. it is only 10 feet from where I am working.
It is a Cisco linksys E1200

I used the 7-23-2013 version of wheezy with all updates and upgrades.
Is it possible I need to get a new version of realtec's 8192cu driver? Or does a relatively new RTL8188CUS chipset need a different driver? Either all of my usb dongles are bad, or the driver is not working correctly between the two pieces of hardware as far as I can see.

fwm
Posts: 6
Joined: Thu May 02, 2013 2:59 pm

Re: Realtek wifi 8188CUS doesn't "just work"

Fri Aug 09, 2013 1:55 pm

As far as power supplies go, the original PS I got with my first RPi came from Allied and was supposed to be a 1A supply, but with a usb wifi plugged in, the system refused to boot for lack of power. Now on all my systems, I use a usb hub with 3.5A power supply to run my Pis. I have swapped the usb wifis from the usb hub back to the RPi several times in testing, all with exactly the same results (none) :(

MrEngman
Posts: 4114
Joined: Fri Feb 03, 2012 2:17 pm
Location: Southampton, UK

Re: Realtek wifi 8188CUS doesn't "just work"

Fri Aug 09, 2013 7:10 pm

The 8192cu driver included with Raspbian is the newest available. I am currently using 2013-07-26-wheezy-raspbian updated to the very latest code using apt-get and rpi-update and have no problems. I have four different wifi adaptors using the 8188cus chip, a couple fairly old, EW-7811Un and SP907NS, and two quite new, EW-7811Un, and they all work without problems and I can swap then about, again without problems, although I almost always connect them directly to the Pi without using a hub. Also they all work with all the older versions of code I have including an old debian 6 image from Apr 2012 with the original 8192cu driver for the Pi available then.

I have just tried connecting to a Linksys router/ADSL modem and it connected without problems. Just changed the ssid and password in /etc/network/interfaces and ran commands sudo ifdown wlan0 and sudo ifup wlan0 and it connected straight away.

Do you see any error messages from command dmesg or in the file /var/log/syslog? What do you see if you run the two commands

Code: Select all

sudo ifdown wlan0
sudo ifup wlan0
Sounds like a possible issue with the set up of the router.


MrEngman
Simplicity is a prerequisite for reliability. Edsger W. Dijkstra

Please post ALL technical questions on the forum. Please Do Not send private messages.

joe213
Posts: 2
Joined: Fri Aug 09, 2013 7:36 pm

Re: Realtek wifi 8188CUS doesn't "just work"

Fri Aug 09, 2013 7:49 pm

Hi,

i think i have the same problem with the same stick - the stick is recognized and found, but it is not possible to connect.

I think the problem is not the security-configuration - the main problem is, that the stick does not find any access points - i'm living in a multi-appartment house with many access points, but none of them is found. I also tried the wlan-hotspot function of my mobile phone, but it's also not found.

Dmesg and syslog do not contain errors.

The scan output:

Code: Select all

pi@raspberrypi / $ sudo iwlist wlan0 scan
wlan0     No scan results
What stick manufacterer do you have? I have the Logilink WL0084A...

Greets Johannes

Edit: I testet 3 other models of wlan-sticks and all worked, they also all found access points and connected successfully.
Last edited by joe213 on Sat Aug 10, 2013 7:08 am, edited 1 time in total.

fwm
Posts: 6
Joined: Thu May 02, 2013 2:59 pm

Re: Realtek wifi 8188CUS doesn't "just work"

Fri Aug 09, 2013 11:26 pm

Posting this from my wireless Pi. Problem (mostly) solved. After booting (again) with the ethernet disconnected and no joy, I removed the wifi usb and reinstalled it hot. That let me see all local wifi points and select mine. But it still would not connect when told to. Removed the usb again and pluged it hot into the Pi usb port (causing the board to reboot) Once it had rebooted, I had connection to my wifi point.

Not sure how reliable this is going to be, as it seems to be hit or miss on the physical connection. It may be the wifi usb just needs to be 'worn in' to make reliable connections.

Thanks to all of you that attempted to help me. I will probably be here some more as I intend to play with relays, cameras, cloud servers, gps's and other goodies.

Hope my solution will help others.

joe213
Posts: 2
Joined: Fri Aug 09, 2013 7:36 pm

Re: Realtek wifi 8188CUS doesn't "just work"

Sat Aug 10, 2013 7:10 am

I tested my LogiLink WL0084A also on Windows - there it also does not find any access points with the original realtek software, so i think maybe the stick has a defect or LogiLink have not implemented it correctly.

peanutman
Posts: 1
Joined: Fri Dec 13, 2013 12:51 pm

Re: Realtek wifi 8188CUS doesn't "just work"

Fri Dec 13, 2013 1:04 pm

I also have an 8188CUS based mini-dongle that didn't work. The solution posted on http://www.fars-robotics.net/ did the trick for me.
It was actually quite simple, leave /etc/network/interfaces alone and restore to default values if needed. Then make /etc/wpa_supplicant/wpa_supplicant.conf look something like this:
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1

network={
ssid="Your-Network-Name"
psk="Your-Network-Password"
}
Then reboot and done!

evanwiley
Posts: 6
Joined: Sun Jan 12, 2014 1:42 am

Re: Realtek wifi 8188CUS doesn't "just work"

Wed Jan 15, 2014 3:42 am

I had the same problem over and over as a NOOB but after:

Code: Select all

sudo apt-get update
sudo apt-get upgrade
then install is app from this link: http://raspberrypi.stackexchange.com/qu ... e-networks

Code: Select all

sudo apt-get install wicd-curses
sudo wicd-curses
I no longer have wifi issues with Realtek.

I turned on Tethering on my phone and connected my PI via the WICD app, my work Wifi and home wifi and now were ever i am my PI auto connects with no issue. Its the best application ever!!!!

--Evan

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