Installing Edimax EW-7811Un on Raspberry Pi

I recently received a Raspberry Pi (which is booting under the Raspbian Wheezy OS), and have been trying to install an Edimax EW-7811-Un wireless adapter on it, since this came highly recommended for compatibility with the hardware. I've followed the guide here: elinux.org/RPi_edimax_EW-7811Un, to no avail - the blue light on the adapter does not come on. I've also tried running the script here: www [DOT] raspberrypi.org/phpBB3/viewtopic.php?f=26&t=6256 which also fails - it incorrectly claims that my network's SSID is not being broadcast.

I'm very new to Linux, so don't know how best to troubleshoot this. I would save the output of dmesg, but have no way to post this - if I unplug the wireless adapter (to plug in a USB stick), then the terminal displays error messages and then becomes unresponsive, and unplugging the keyboard is clearly unhelpful. I've tried saving log files to my SD card and reading that on an internet-connected computer, but the card is unrecognisable on my laptop.

If there are any common error messages that you could tell me about, I could look out for them in my dmesg output - otherwise, I'd appreciate advice on how to post the log files to aid debugging, or possible mistakes I might have made in installing the Edimax.

(Apologies that the URLs are not formatted correctly - apparently, I only gain that privilege after 15 posts)

I have both the pieces of kit you're trying to connect here. The wireless adaptor, in my opinion, is utterly crap. I tried to have it working from my Fedora box, but it was totally unreliable. I could get it to connect for a few seconds, but then it would disconnect and remain (mostly) disconnected - even when I had the access point right next to it. Eventually I gave up.

My suspicion (none of this is confirmed, btw, it's pure speculation from what I've seen of this adaptor) is that it needs to draw quite a bit of power from the USB port to overcome the tiny size of its antenna, and the desktop Intel Atom m/b I was using just couldn't give it enough juice. I would never dream of plugging this into my R-Pi to make a connection because I'm not sure the little PSU I'm using is up to the job.

All I can suggest is that you get the biggest power adaptor you can for your Pi, or (even better) get a powered USB hub and run it off that. It might help.

Thanks for the feedback.

Do you know of a Linux command to check the power levels? For reference, here's the power supply that I'm using; www[DOT]amazon.co.uk/gp/product/B008MWDTW4/ref=oh_details_o04_s00_i00

I don't know of any command that'll tell you that.

You can take a look at the power device itself, though. That white label under the plug pins should tell you how much it kicks out. You'd measure the power by looking at the output voltage and current (power = amps x volts, remember) but as it's a USB device it should run a standard voltage. Normally these things kick out 500mA to 1A, but I think you can get slightly stronger ones. 1A ones are not particularly expensive, but is probably more beneficial to buy a wireless connector with lower power consumption requirements.

Here is the other one I use, and I've found to be more reliable on my Intel Atom PC (and anything else I've plugged it into).

If you want to change power supply, you want to look for something like this kinda thing. I'm not recommending this particular one, btw, its just what a search of Amazon turned up. It happens to be at least twice as expensive as I'd expect to pay for one of these.

Thanks for the advice.

What do you know, though - after a(nother) clean install of Raspbian and re-run of the linked script, the Wifi Adapter worked perfectly.