WiFi and graphical session


10 posts
by Julian » Fri Jun 29, 2012 9:48 am
I am not new to linux (debian to be precise) but I haven't used it in a long time as a desktop environment.

Hardware: Logilink WL0085 (Chipset: RLT8188S) connected via active USB hub
Distribution: Debian squeeze/wheezy (both have the same problem)
Software: wicd (wicd-curses for console/wicd-gtk for X)

I have setup the WiFi adapter noted above with wicd (connected via WPA). When I am not running a graphical session all works fine. Even with only 40% signal strength I can browse the web via links2, mount samba shares and transfer files via mc.
When I startx the wicd icon in the taskbar shows a good connection, but I am not able to connect to anything. A Terminal and iwconfig shows "associated" after starting up X but after about 20 seconds it gets disconnected. The wicd-client itself is not usable. It takes forever to load, does not find networks or hangs on connecting to one (I killed it after waiting about 10 minutes). About 3 minutes after starting X the wicd icon shows that the connection is broken. I tried killing the wicd-client and using wicd-curses via LXTerm but I can't control anything (its not responding to any keyboard commands). After about 20 seconds it crashes and the terminal output says something about dbus connection timed out. It seems that X is using up so much processing power that wicd is not stable anymore. So I am able to use the massive LibreOffice Writer to compose texts but wicd does not work? I also tried setting up the network using only wpa_supplicant and a configuration file. The problem is the exact same.
Any ideas how to fix this? I know that the Rasberry Pi ist not a fast machine but is it really to slow to handle X and a wireless connection at the same time?
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by RaTTuS » Fri Jun 29, 2012 10:34 am
is this being used though a Powered USB hub?
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by Julian » Fri Jun 29, 2012 10:55 am
yes the WiFi Adapter is connected via a powered USB hub.
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by Julian » Fri Jun 29, 2012 5:32 pm
It really seems to be a power problem. When the WiFi adapter is directly plugged into the rpi it does not connect at all (although the power between TP1/TP2 is stable at 5,02V-5,04V; I am using a 1A power supply). The USB hub is only lend, so I will buy one from the "RPi VerifiedPeripherals" Wiki page. I will report back next week if this helps.


The PI's USB ports are unsuitable to power a WiFi adapter!
A wifi adapter isn't able to work with 4.4 Volt, (or less) which is about what remains after the USB polyfuses (designed for simple keyboards and mice) when drawing the kinds of currents any WiFi adapter will draw.
Simple USB keyboards (and mice) are designed to work with 4.4 Volt, and will also draw low enough amounts of current to make sure that the voltage after the polyfuses will stay above 4.4 Volt.

resuming:
A wifi adapter draws too much current for the USB ports of a PI
and
A wifi adapter cannot work on the kind of voltages an USB mouse works with, which is all the PI will give the USB device.

The PI is only designed to work with these 4.4 Volt devices, try "anything funny" and you are using the PI for something it wasn't designed for?

Blame the USB polyfuses for that, (which are chosen for 100mA max 4.4 Volt devices) and the fact that the PI was designed for use with a 5V 0.7A power supply, which only has 200mA assigned to the USB ports..

Either use the non compatible device behind a powered USB hub that doesn't draw power from the PI (the 5V from the PI shouldn't be connected to the 5V of the hub, as some cheap hubs do, ignoring USB specifications, so the hub can also be used without a PSU) or bypass the USB polyfuses, (that is, solder a wire over them) a procedure nicknamed the "PI-pass" in these fora.

Search for "polyfuse" for more threads about this issue.
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by Julian » Fri Jul 06, 2012 5:53 pm
Just for the archive:
Buying a new powered usb hub (D-Link H4) didn't help. So I tried disconnecting the power line in the USB Cable which made the hub unusable (hub is constantly resetting it self). So I tried again with the lend usb hub (an old Hama 1:4) and the modified USB cable. The hub is working great but the problem with the wifi is the same. I am using raspbian at the moment which shows me a lot of "ADDRCONF(NETDEV_UP): wlan0: link is not ready" messages. Also when the LogiLink wifi adapter is plugged in and activated (module loaded/interface up) my new wireless keyboard I ordered with the hub is not working anymore (buttons get "stuck" or presses don't not recognized at all). Just to clarify: the keyboard receiver is directly connected to the Rpi, the wifi adapter via a powerd usb hub with no VCC line in the cable. I am pretty sure now that its a driver problem so I ordered a wifi adapter from the "compatible list" yesterday and I will add mine to the non working list.
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by Gerhard Schwarz » Sat Jul 07, 2012 6:25 am
Julian wrote:... I am pretty sure now that its a driver problem so I ordered a wifi adapter from the "compatible list" yesterday and I will add mine to the non working list.


I (and many others) face a similar problem: my WiFi-dongle works fine when the keyboard OR the mouse are plugged in, but it denies service when both of them and the WiFi-dongle are connected to the USB-hub simultaneously.

It seems this is not a problem related to the WiFi-dongles or their firmware/drivers, but is an issue related to the USB-ports of the RPi itself. There's quite a discussion going on about this topic in one of the forums here (sorry that I can't provide you a link, unfortunatelly I forgot the forum's name and have to find it again myself).
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by Badger101 » Sat Jul 07, 2012 11:15 pm
Gerhard Schwarz wrote:
Julian wrote:... I am pretty sure now that its a driver problem so I ordered a wifi adapter from the "compatible list" yesterday and I will add mine to the non working list.


I (and many others) face a similar problem: my WiFi-dongle works fine when the keyboard OR the mouse are plugged in, but it denies service when both of them and the WiFi-dongle are connected to the USB-hub simultaneously.

It seems this is not a problem related to the WiFi-dongles or their firmware/drivers, but is an issue related to the USB-ports of the RPi itself. There's quite a discussion going on about this topic in one of the forums here (sorry that I can't provide you a link, unfortunatelly I forgot the forum's name and have to find it again myself).


I agree. I've taken out all the polyfuses and replaced them with real fuses, lifted the 5v input to the USB fuses and supplied a good stable 5v and it hasn't made any difference (but XBMC iPlayer streaming is alot better)
Badger.
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by captainwebb » Thu Jul 12, 2012 3:35 pm
Mmmmm ... Well, I have a RT5370 running directly off the Pi's USB, apparently successfully. Just two quirks:-

1. For some reason, the Pi configured the wifi as wlan1. Any idea why this should happen?

2. When I start LXDE, I get two warnings. The first says "Could not connect to wicd's D-Bus interface. Check the wicd log for messages." I OK that, then get "The wicd daemon has shut down. The UI will not function properly until it is restarted". I OK that. The Pi is connected to my router, and my internet access (via Midori) is good.

What do I need to do to resolve the wicd messages (or to remove it entirely - I don't plan on taking my Pi on walkabout to other networks).

Oh, I should have said, I'm running the "wheezy" beta.
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by Julian » Thu Jul 12, 2012 5:40 pm
captainwebb wrote:Mmmmm ... Well, I have a RT5370 running directly off the Pi's USB, apparently successfully. Just two quirks:-

1. For some reason, the Pi configured the wifi as wlan1. Any idea why this should happen?

2. When I start LXDE, I get two warnings. The first says "Could not connect to wicd's D-Bus interface. Check the wicd log for messages." I OK that, then get "The wicd daemon has shut down. The UI will not function properly until it is restarted". I OK that. The Pi is connected to my router, and my internet access (via Midori) is good.

What do I need to do to resolve the wicd messages (or to remove it entirely - I don't plan on taking my Pi on walkabout to other networks).

Oh, I should have said, I'm running the "wheezy" beta.

I am using raspbian and IceWM with the same problem. My new WiFi Adapter has a RT2870/RT3070 chipset. I just removed wicd completely and I am working with wpa_supplicant directly which is working great. I also am powering the deivce directly from the RPi. Connecting it through a powered usb hub (I have tested two) just causes problems.
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by brhottman » Tue Sep 25, 2012 9:14 pm
Try this for a fix it worked for me.




quit wicd (right click on icon)

open LXTerminal

raspberry@pi:~# sudo dpkg-reconfigure wicd
raspberry@pi:~# sudo update-rc.d wicd defaults

reboot
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