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Review of the UT-41 GPS, and a little about getting it to work with
Kismet in BackTrack Linux
Review of the UT-41 GPS, and a little about getting it to work
with Kismet in BackTrack
Linux
Awhile back I was looking for a low cost GPS on Newegg.com to do some wardriving
with. Being the cheap bastard that I am I did not want to pay more than $60 for
it, and even most mouse type GPS units cost more than that. Unfortunately,
NewEggs cheapest one was out of stock so I kept looking
around. Eventually I found the UT-41 GPS on Geeks.com (see the links section at
the bottom of this page). Hey, for $34.99 (about $42 after shipping) I was
willing to give it a try seeing as it was about the cheapest GPS I could find
(even if it did look like a black sperm). After doing a little online research I
found that others had had some success getting it to work under Linux, and Linux
compatibility was a must for me since I use Kismet (wardriving in Windows
without monitor mode is like having sex with the lights off, you miss so much.).
I'm happy to say it works fine, once I did some Googling around to figure out
how to get it to work. As a service to the community, and to make a one stop
search for the next person trying to get this GPS to work, here are my notes on
getting the UT-41 running in Linux with Kismet. A lot of the info should be
helpful users of other GPS models as well. What follows are my notes, first for
Window, then Linux.
Windows XP/2000
The first thing I did when I got
the GPS was try to get it working in Linux, but after a few problems I figured
it would be best to troubleshoot it first by testing the unit in Windows. The
Windows install was easy, it seems the UT-41 is just a GPS receiver and a
Prolific 2303 serial to USB converter in one package. I installed the Windows
drivers off the CD (the ones on
Prolific's website work also), plugged in the GPS and it loaded just fine. After
that I just had to determine what COM port it was on in Device Manager, then set
my apps to use that port as a
NMEA-0183 GPS.
I even got Earth Bridge to work with Google Earth. Giver Earth Bridge a shot
if you use Windows, it's a fun little path tracking tool and it's free (Donation
Ware at least). One bit of weirdness, under Windows my GPS seemed to work while
I was indoors next to a south facing window, however in Linux I had to be
outdoors. If anyone knows why, email me.
Linux (BackTrack and Kanotix)
It took me a bit of looking around
to figure this out, but it's not hard. Most of my confusion was cause because I
could get a LAT/LONG in Windows indoors, but I had to be outside with Linux.
Here are the basic steps to get the UT-41 to work in Linux, along with a few
trouble shooting commands.
Gpsd is the daemon Kismet and most
other Linux apps use to talk to a GPS. In BackTrack I had to use these the
following gpsd command to get it running:
gpsd
/dev/tts/USB0
This device name is rather abnormal since in most Linux distros, including
Kanotix, you use
/dev/ttyUSB0 as your first serial USB device. After gpsd is started you can run
Kismet. In BackTrak it's easiest just to use their config script:
start-kismet
After you run start-kismet it will ask you what WiFi device
to use, and where to save the data. In other distros you will have to
configure Kismet yourself. In Kanotix I had to edit my /etc/kismet/kismet.conf
file and change two lines. First, the one that looks like:
source=madwifi_ag,wifi0,atheros
The above line is what I had to use for my SMC2336W-AG
PCMCIA card, yours will most likely be different. Just look for the line in
kismet.conf that starts with "source=" and change it accordingly. You will
also want to find the line that starts with "gps=" and set it to true:
gps=true
once that's all done, you can just start Kismet as root. With a hard drive
install of Kanotix you should be able to find your logs in "/var/log/kismet/".
Linux Trouble shooting
If your UT-41 is still giving you fits, try these trouble shooting
commands:
See if the USB GPS is found:
root@bub:~#
lsusb
Bus 001 Device 002: ID 067b:2303 Prolific
Technology, Inc. PL2303 Serial Port
Bus 001 Device 001: ID 0000:0000
root@bub:~#
You see from the above that it found the
Prolific serial device.
Make sure that the GPS is connecting with gpsd by telneting to it and putting
it in raw mode. Hitting enter by itself should just return the string "GPSD" but
if you enter the "r" command you should get a stream of data that looks
something like this if it is working:
root@bub:~# telnet localhost
2947
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
If you compiled GSPd, you can run the following
command in terminal
gpsd tty.PL2303-0000103D
or if you are using the GUI you might have to refresh
the serial list, and then select /dev/tty.PL2303-0000103D
To see if it is working, you can telnet to your
localhost, press "r" and enter and you should see some GPS data like so.
telnet localhost 2947
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
GPSD
GPSD
r
GPSD,R=1
$GPGSV,3,2,12,17,47,258,,27,33,173,,24,16,189,,29,13,287,*74
$GPGSV,3,3,12,26,13,293,,19,05,056,,20,03,125,,04,02,199,*7A
$GPRMC,224206.00,V,3818.6285,N,08552.2345,W,,,200906,,,N*59
$GPGGA,224206.00,3818.6285,N,08552.2345,W,0,00,0.0,,M,,M,,*4F
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
After that you can select GPS under Preferences, and choose GPSd in the
drop down. After words you should have GPS working in OS X with the
UT-41.
Closing
That should about cover it. All in
all, I can't complain about the UT-41 for the price. I'm sure there are a lot
better GPS units out there, but with it's magnetic base, Linux compatibility and
low price I'd have to recommend it for folks just getting into wardriving who
don't want to spend a lot of cash.
If you want to know more about
wardriving tools in general check out the following videos:
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