[PLUG] Wireless Cards - (was "Linux Clinic today")

Keith Lofstrom keithl at kl-ic.com
Mon Oct 16 20:12:07 UTC 2006


On Sun, Oct 15, 2006 at 06:11:15PM -0700, John Jason Jordan wrote:
> Another fine clinic! 

And John is instrumental in making that happen.  One thing, though;
we are all there to have fun, and solving small Linux problems is
fun.  Solving huge problems is work, and not fun.


One of the larger problems we have is people bringing in odd bits
of hardware they picked up cheap and expecting us to get them going.
The most common example of such hardware is cheap Frys wifi cards
for laptops.  We have good success with Atheros G chipsets and with
PRISM-II B chipsets, but most cheap cards use Windoze-only chipsets
with poor or nonexistent Linux support.  That is the nature of
Wifi cards, and it is rooted in FCC requirements supported by
proprietary vendors.  That said, some vendors "get it", and you
should support them.  You have to do some study of individual card
types, and the chipsets they use, BEFORE you buy them.  If you don't
know that a card will work, DON'T BUY IT, and DON'T expect the clinic
volunteers to compensate for your carelessness.  There is plenty
of good wireless hardware that you can buy with good manufacturer
support for Linux.  Here are two good lists of working chipsets:

  http://www.seattlewireless.net/HardwareComparison
  http://www.linux-wlan.org/docs/wlan_adapters.html.gz

And if that is too hard, just look for Senao NL-2511 (PRISM-2.5) on
the web and buy those.   Cheap and good range.  They are not G cards,
but how often does the wireless access point connect to something
faster than 11 Mbps anyway?  

If your laptop has builtin wireless, you might be able to get that
running with some work.  However, laptop builtin chipsets are often
obscure (we spent 4 hours fighting a Broadcom BCM43xx chipset), and
even if you get them running they are typically low power with limited
range.  Personally, I prefer a card that I can pull out and keep in
my pocket - then I can be sure I am offline, whether or not my software
has been damaged, and I am not wasting battery power while offline.

You can get many windows drivers to work with something called 
"ndiswrapper" - sometimes that works, often it does not.  It is just
one more thing that can go wrong.

The Linux clinic is currently being held at FreeGeek;  wireless service
there is "special".  Most of the time it works good, but if there is
someone in another part of the building using wireless then the diversity
antennas may point at them rather than you.  There are other open APs
nearby that can interfere.  In general, it is not a very good place
to debug Linux wireless, and most of the volunteers are not wireless 
experts.  Fortunately, I was able to help one fellow debug an Atheros
chipset DLINK WNA-2330 card (after we fixed yum and found a spot in
the building that would connect) but two other fellows were not so
lucky, and there was much hair pulling and gnashing of teeth.  

One way to deal with wireless cards and laptops would be to schedule
quarterly "wireless days", perhaps in conjunction with the Personal
Telco Project.  We would want a venue where we control the wireless 
environment (our own AP, no others in range), good connectivity (for
looking up things on the web, and downloading drivers) and plenty of
wireless savvy people (Tom Higgins, Don Park and Russell Senior 
spring immediately to mind, but there are plenty of others).  This
would not be a monthly thing.

Also, since the lists above are kind of old, it would be handy to
do a monthly "store scan" to update a list of currently available
wireless cards at Frys and Compusa and Bestbuy (and other stores
that carry them) and then research them for chipsets and drivers.
That does not require a rocket scientist, anyone who wants to 
contribute to the community can do that.  We can divide cards into
"easy", "difficult", and "impossible".  Impossible cards will be
taken out to the sidewalk and stomped.  You Have Been Warned.

And for built-in wifi - assume that doesn't work.  If you get it
working, that's wonderful.  Write down what you did and share it
with others.  But just because somebody somewhere got the built-in
working with their own particular setup, that doesn't mean we can
get YOURS working in just a few hours.  It is far easier to buy a
card that lots of people have gotten working with many versions of
Linux.  You paid >$500 for the laptop; be a mench and spend >$40 
for a wireless card.

Keith

-- 
Keith Lofstrom          keithl at keithl.com         Voice (503)-520-1993
KLIC --- Keith Lofstrom Integrated Circuits --- "Your Ideas in Silicon"
Design Contracting in Bipolar and CMOS - Analog, Digital, and Scan ICs



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