in the course of development on the soup project, i definitely had to look for a solution to get data from kismet on my powerbook in a more or less portable way (portable in the sense of carrying things around). because my 12" model does not have a pcmcia card slot and there is no driver which supports monitor mode for the integrated airport extreme card i had to head for another device which provided me with the necessary data. one option was to go for an intel compatible laptop with pcmcia slot and get an orinoco card. because i did not want to buy another machine and - more important - cannot afford it, i've gone another way.
the linksys wrt54g access points have plenty of pretty features but the best of all is: it runs linux and the firmware is opensource. i've chosen openwrt, because it features a good packet management system and it is widely used and well documented. putting the firmware onto the device was pretty easy and getting the newest kismet too, so i'll continue with the actual subject of this article.
my wrt54gs v1.1 has an external power supply and the specs claim, that it feeds the device with 12 Volts / 1 Ampere. according to the apple hardware documentation the firewire bus of my powerbook runs on 12.6V and provides a maximum of 7 Watts. with a multimeter i measured the actual power consumption of the wrt54g and realized that the firewire port easily will provide enough power for the device. i measured 0.22 A on 12 V which results in a total input of 2.64 W.
so i happily cut one of my firewire cables (which actually was broken already and caused heavy problems when attached to the dvd burner or external harddrive) into two peaces and soldered a suitable power connector onto one of the ends. after i double checked the cable, the specs and my calculations i was brave enough to stick my new wrt54g power supply cable into the firewire bus of the powerbook and connect it to the wlan router. the device happily began to flash with its lights and my beloved powerbook did not die. yes!
i logged into the router and started kismet and finally found the networks popping up in my osx terminal window, without having to connect either of my devices to a power outlet. happy wardriving on 12" powerbook.
warning: before you race to your toolbox and heat up the soldering iron you better read the hardware docs for your devices and make clear you understand what you wan't to do. work accurate and don't put together the connecters and cables sloppy. i don't want to know how your computer reacts to short cirquits and shakey connections!
keep in mind that you can destroy your computer, every connected device including your data on the harddrive everithing else laying around on your desk. any liabilities are excluded.
check out the gallery for pictures
- Lorenz
