USB Wireless Adaptors are a curious product category with what would initially appear to be a rapidly dwindling market. It’s hard to find anything these days without WiFi built right in. But there’s an ever-growing demand for USB WiFi Dongles in an unlikely place; the world of homebrew hardware, Raspberry Pi’s, Beagle Boards and OpenPandora consoles.
Many of these devices err on the side of low-cost, and omit a WiFi adaptor because they don’t generally need one. The Pandora console, on the other hand, includes WiFi but it’s not terribly fast or stable. Knowing what micro WiFi adaptors work with these things is, therefore, tantamount to getting your new device online. And this will be particularly true of the Raspberry Pi, which seems set to rock the world on February 29th… that’s tomorrow if I get this article published on time!
RealTek chipsets are known to have reasonably decent linux compatibility, so I’ve been putting my feelers out, grabbing as many Micro WiFi adaptors as possible, and seeing what guts they have inside… not by disassembling them, of course, but with a bit of “lsusb -v” magic.
The Sandberg Micro WiFi USB Dongle was the first to arrive, and is a RealTek based WiFi adaptor based on the 8176 chipset which gets picked up by the rtl8192cu driver. Thus, for the OpenPandora console at least, it’s pretty much plug-and-play. This should bode well for the Raspberry Pi, too, with drivers being a quick and simple cross-compile away for pretty much any linux-based operating system you decide to run.
Although the Sandberg is Wireless N compatible, you can pretty much forget getting those ultra-fast speeds in Linux, but it’ll serve you well enough for high-definition video streaming, which is about as intensive as any WiFi usage is going to get. Fortunately, signal strength doesn’t appear to be mitigated by the tiny, tiny size of the dongle. This should be expected, I suppose, with WiFi chipsets being miniaturised for mobile devices they should be pretty good by now! I can get a good quality signal from anywhere in the house with a rate of about 65 Mb/sec, which is a damn sight better than the frequent 1 Mb/sec that the Pandora gets on its lonesome.
On the Pandora the Sandberg Micro WiFi dongle sticks out of the USB port by a couple of millimetres because the port isn’t recessed like it would be on most laptops. This may also apply to the Pi, but until I get my hands on one I wont be able to confirm it. Obviously it’s less of an issue on the Pi, where pocketability isn’t much of a concern, and Pi cases may or may not recess the USB port in a similar fashion to laptops.