Model B+ and EDIMAX EW-7811Un WLAN-Stick - Raspbian crashes

[rosenfranz]

Hello everyone!

This one's driving me crazy and I hope there's someone out there with the same problem and - hopefully - a solution .

I have a brand new Raspberry Pi Model B+.
I installed the newest Version of Raspbian via NOOBS (Version 1.3.10, 2014-09-12).

Furthermore I use a standard apple keyboard and an a wireless mouse. My screen is connected via HDMI.
To get the pi into the word wide web I wanted to use an EDIMAX EW-7811Un WLAN-Stick. I did this before with my old Model B Raspi. Worked like a charm, plug-and-play.

When I plug this edimax wlan stick into my Raspi B+ however the system (or just the USB Ports) crashes. Unplugging doesn't get it back to live. To reboot I have to pull the power cable.

I read that some people had problems with the new raspi's USB Ports. But only with an older version of NOOBS. As this could be fixed by an 'sudo apt-get update' and an 'sudo apt-get upgrade' I too did these. No changes.

I have no clue what the problem might be here, for there's a lot of people out there using the exact same setup flawlessly. This wlan stick is even recommendet for the use with the raspi.

Any ideas?
Has anyone encountered the same problem?

[jamesh]

I'd guess a power supply problem. Try a better supply, and probably a better lead as well.

[rosenfranz]

Thanks for the reply.
I was thinking about that, too. Right now I'm using a microUSB power supply unit that delivers 1.2A and 5V. I thought 1.2A should be enough since the new raspi needs even less power than its predecessor. With the latter I used this power supply unit before while I had this wlan dongle, a keyboard and a mouse hooked up to the pi. Never had any problems.

[rosenfranz]

Correct. The problem was the power supply.

I just got myself a new power unit with 5V and 2A.
Everything works fine now.

Interesting to know that those 1,2mA Power Units are not quite useful for the B+
even though they keep telling you everywhere that they're suitable for it. As long as you don't need your raspi to connect to a WLAN that is correct.

[pluggy]

1.2 amp is plenty, but never believe a label.....

My much maligned Samsung 700mA charger will power a B+ with keyboard and stand hot plugging a cheap RTL8188CUS wifi adaptor. ( Cheap no-name version of the Edimax EW-7811 ).

Unfortunately, the B+ doesn't have an easy way of checking the voltage with a meter like the old B. It can be done, but its on fiddly little pads on the underside.

[rosenfranz]

Correction. The power supply was not the problem.

It only worked for a short time when I was using the pi with a small tft-screen that goes onto the gpio-pins like a shield.
The vendor of those things offers a Raspbian image for download where the thing is already setup and good to go. After I got the new power supply unit everything worked with that particular image.
However I decided to send the tft-screen back as I was not satisfied with its performance. So I went back to a blank noobs raspbian installation in order to have hdmi as the default output again and to get rid of all the unnecessary files that made the tft run.

Now, with that fresh installation the edimax ew-7811un wlan-dongle is making trouble again. as soon as i plug it in no more reaction from the usb ports. I tested the dongle on a windows pc and it works just fine. I directly connected the pi to the web with an ethernet cable in order to do sudo apt-get update, sudo apt-get upgrade and sudo rpi-update. Still no changes.
I've had enough now so I will send the pi b+ back and reorder the regular b instead. Never had any problems with the latter and the edimax dongle. Plug-and-play as it should be.

If anyone else still encounters this same problem and finds a solution, please let me know. I'm still interested for this cost me a lot of time and testing.

[rosenfranz]

oki doki one last post. with the evening passing by I couldn't take my hands of the pi and gave it one last try. Everything works now. Here's what I did.

Formatted the SD-Card once again (using SDFormatter for Mac). Instead of NOOBS, this time I directly downloaded the Raspbian Image from raspberrypi.org and put it on my empty MicroSD-Card using the ApplePi-Baker App.
Started up the Pi with the fresh SD-Card and only my keyboard, mouse and screen connected. In raspi-config, which automatically shows on first startup, I switched on SSH. Then again I directly connected my pi to my router (thus to the www) via ethernet cable. Via ssh I now did apt-get update, apt-get upgrade and finally rpi-update for the newest firmware. Shutdown the pi after that, unplugged the ethernet cable. I now plugged in keyboard, mouse, screen AND edimax dongle and … tada! Everything works. I could start into x and setup my wifi connection without any problems.

What a strange journey...