| Andrew Cooke | Contents | Latest | RSS | Twitter | Previous | Next

C[omp]ute

Welcome to my blog, which was once a mailing list of the same name and is still generated by mail. Please reply via the "comment" links.

Always interested in offers/projects/new ideas. Eclectic experience in fields like: numerical computing; Python web; Java enterprise; functional languages; GPGPU; SQL databases; etc. Based in Santiago, Chile; telecommute worldwide. CV; email.

Personal Projects

Lepl parser for Python.

Colorless Green.

Photography around Santiago.

SVG experiment.

Professional Portfolio

Calibration of seismometers.

Data access via web services.

Cache rewrite.

Extending OpenSSH.

C-ORM: docs, API.

Last 100 entries

SFO Get Libor Trader (14 years); Why Are There Still So Many Jobs?; Navier Stokes Incomplete; More on Benford; FBI Claimed Vandalism; Architectural Tessellation; Also: Go, Blake's 7; Delusions of Gender (book); Crypto AG DID work with NSA / GCHQ; UNUMS (Universal Number Format); MOOCs (Massive Open Online Courses); Interesting Looking Game; Euler's Theorem for Polynomials; Weeks 3-6; Reddit Comment; Differential Cryptanalysis For Dummies; Japanese Graphic Design; Books To Be Re-Read; And Today I Learned Bugs Need Clear Examples; Factoring a 67 bit prime in your head; Islamic Geometric Art; Useful Julia Backtraces from Tasks; Nothing, however, is lost with less discomfort than that which, when lost, cannot be missed; Article on Didion; Cost of Living by City; British Slavery; Derrida on Metaphor; African SciFi; Traits in Julia; Alternative Japanese Lit; Pulic Key as Address (Snow); Why Information Grows; The Blindness Of The Chilean Elite; Some Victoriagate Links; This Is Why I Left StackOverflow; New TLS Implementation; Maths for Physicists; How I Am 8; 1000 Word Philosophy; Cyberpunk Reading List; Detailed Discussion of Message Dispatch in ParserCombinator Library for Julia; FizzBuzz in Julia w Dependent Types; kokko - Design Shop in Osaka; Summary of Greece, Currently; LLVM and GPUs; See Also; Schoolgirl Groyps (Maths); Japanese Lit; Another Example - Modular Arithmetic; Music from United; Python 2 and 3 compatible alternative.; Read Agatha Christie for the Plot; A Constructive Look at TempleOS; Music Thread w Many Recommendations; Fixed Version; A Useful Julia Macro To Define Equality And Hash; k3b cdrom access, OpenSuse 13.1; Week 2; From outside, the UK looks less than stellar; Huge Fonts in VirtualBox; Keen - Complex Emergencies; The Fallen of World War II; Some Spanish Fiction; Calling C From Fortran 95; Bjork DJ Set; Z3 Example With Python; Week 1; Useful Guide To Starting With IJulia; UK Election + Media; Review: Reinventing Organizations; Inline Assembly With Julia / LLVM; Against the definition of types; Dumb Crypto Paper; The Search For Quasi-Periodicity...; Is There An Alternative To Processing?; CARDIAC (CARDboard Illustrative Aid to Computation); The Bolivian Case Against Chile At The Hague; Clear, Cogent Economic Arguments For Immigration; A Program To Say If I Am Working; Decent Cards For Ill People; New Photo; Luksic And Barrick Gold; President Bachelet's Speech; Baltimore Primer; libxml2 Parsing Stream; configure.ac Recipe For Library Path; The Davalos Affair For Idiots; Not The Onion: Google Fireside Chat w Kissinger; Bicycle Wheels, Inertia, and Energy; Another Tax Fraud; Google's Borg; A Verion That Redirects To Local HTTP Server; Spanish Accents For Idiots; Aluminium Cans; Advice on Spray Painting; Female View of Online Chat From a Male; UX Reading List; S4 Subgroups - Geometric Interpretation; Fucking Email; The SQM Affair For Idiots; Using Kolmogorov Complexity

© 2006-2015 Andrew Cooke (site) / post authors (content).

Linux USB Wifi With TP-Link TL-WN722N

From: andrew cooke <andrew@...>

Date: Wed, 15 Jun 2011 21:31:20 -0400

I've recently been interested in security again.  One consequence of this was
trying to get some handle on how useful wifi antennas (cantennas, pringles
etc) are.

(Incidentally, it turns out that you can make a cantenna by wrapping a plastic
bottle in foil - that makes it much easier to get something the right size)

Anyway, to connect a cantenna to a laptop, you need an aerial socket.  While
my laptop has wifi, it doesn't have an external socket.  And, just as
importantly, it has to be supported well on Linux.

After reading around, it seemed that Atheros chips are as good as anything
these days.  And a local shop had in stock (this is Chile, so you have to take
what you can find) something called a TP-Link TL-WN722N for less than 10
pounds.

So I bought one.

And it works with opensuse 11.4 out of the box, as a simple wifi card.
Unfortunately, if you try to use it with aircrack-ng you get the notorious
"channel -1" error.  The way to fix this is explained at
http://www.aircrack-ng.org/doku.php?id=compat-wireless - follow the
instructions there to install new, patched drivers.  One small caveat - the
driver select script didn't work (ie after using it, my wifi was broken); but
building and installing everything did work.

Also, for the record, if you're seeing some other channel number, clean out
your settings - delete the config for wifi, place it under ifup and don't
configure anything - and then reboot.

Andrew

Stability Issues

From: andrew cooke <andrew@...>

Date: Wed, 22 Jun 2011 23:34:05 -0400

The above was rather unreliable (crashes when using the WiFi card, particular
if hibernating).  So I am now trying with the OpenSuse source.  This includes
the additional pathes added by OpenSuse.

For a good description of the process below see http://
linuxmafia.com/pub/linux/suse-linux-internals/chapter34.html - all we are
doing is downloading the source, unpacking it (and applying the OpenSuse
patches), adding the extra patches, compiling and then installing.

This builds for all kernels at the same time, btw (default, desktop and xen).

 zypper source-install compat-wireless
 tree /usr/src/packages/
 cd /usr/src/packages/SPECS
 rpmbuild -bp compat-wireless.spec
 tree ../BUILD/
 cd ../BUILD/compat-wireless-2.6.38.2-2-ns/source/
 wget
 http://patches.aircrack-ng.org/mac80211.compat08082009.wl_frag+ack_v1.patch
 wget http://patches.aircrack-ng.org/channel-negative-one-maxim.patch
 patch -p1 < mac80211.compat08082009.wl_frag+ack_v1.patch
 patch -p1 < channel-negative-one-maxim.patch
 cd ../../../SPECS/
 rpmbuild -bc --short-circuit compat-wireless.spec
 rpmbuild -bi --short-circuit compat-wireless.spec

That didn't install anything so I then tried

 /usr/src/packages/BUILD/compat-wireless-2.6.38.2-2-ns/obj/default
 make install

which does work (and replaces at least the last line earlier).

Andrew

Comment on this post