Some time ago I got my hands on a bunch of more or less broken Linksys 802.11 APs and wireless routers. They have been sitting in my closet until recently, when I decided to mock a bit with one of the WRT54G models.

First things first – I had to establish contact with the onboard firmware. Since the board didn’t respond on any of the ethernet interfaces I set out to construct an RS-232 level converter to use with the onboard 3.3V TTL serial interface.

Judging from google, people use all kinds of weird and somewhat complicated (not to mention quite expensive) circuits in order to convert the voltage levels of the WRT54G serial interface to RS-232 levels. I decided to go with my own simple, cheap and effective design based on the Maxim MAX3232 as shown below:

The pinout of the IDC connector on the Linksys WRT54G – X3 in the diagram above – is as follows (thanks to Rod Whitby for posting information on the pinouts, saved me a bit of trial-and-error):

The onboard firmware of the WRT54G provides a console on ttyS0 at 115200 1N8. Since the above pinout lacks RTS/CTS lines we have to rely on software flow control.

To connect to the console one might use a command like cu(1):

$ cu -l /dev/ttyU0 -s 115200

Below is a couple of action-shots of the circuit in use:

The next logical step is to get FreeBSD/mips up and running on this thing ;-)

Several people have asked me about the system monitor running on the root window of my ThinkPad X60s’ X11 desktop – not many of them had spotted that is was actually just conky with an advanced configuration and a custom wallpaper:

My ~/.conkyrc can be downloaded from here. The panel at the bottom center is from FluxBox, my window manager of choice. The panel to the left is fbpager, a desktop pager for use with FluxBox.

This years EuroBSDCon was great fun! It was the second time I attended EuroBSDCon, and it was great meeting up with – what has come to my understanding is – the “usual crowd” again.

The talks this year were very high quality and the social and networking aspect was very enjoyable – ranging from Robert Watson’s talk about the TrustedBSD enhancements to the traditional Unix security model to my ZFS debug session with Pawel Jakub Dawidek.

I took a few, muddy photos at the conference – they can be found at the usual place. See you all next year in Strasbourg!

EuroBSDCon 2007 starts in a few days. It will take place in Copenhagen, Denmark this year, so my travel time is greatly reduced compared to last year (where it took place in Milan, Italy).

I am especially looking forward to Sam Leffler’s talk about long distance wireless networks, Robert Watson’s talk about FreeBSD security features and Kirk McKusick’s talk about the BSD fast filesystem – and, of course, networking with other *BSD enthusiasts.

Erwin kindly offered me a ride on his bike to get there, so hopefully the weather gods wont be too agry the next couple of days ;)

Oh, and remember to bring two government issued photo IDs if you want me to sign your PGP/GPG key or a CACert Web of Trust form.

See you in Copenhagen!

Ryan Woodings, Chief Geek at MetaGeek, LLC kindly donated a Wi-Spy 2.4x spectrum analyzer to me, thus allowing me to work on getting it supported in FreeBSD like I did with their earlier product. Thanks!

I must say, the Wi-Spy 2.4x simply rocks. It’s resolution is much better (3x) than that of 1st generation Wi-Spy and the external antenna is of course a nice addition as well. Below is a photo of my two Wi-Spys for comparison.

Here’s a screenshot of the current development version of spectrum-tools (formerly wispy-tools). The top graph is from my new Wi-Spy 2.4x, the bottom graph is from my 1st generation Wi-Spy – you can clearly see the improved resolution and amplitude range of the Wi-Spy 2.4x.

The yellow line is the current signal level, the green is the average signal level and the blue is the peak signal level.

My patch which adds support for the Wi-Spy 2.4x to the FreeBSD kernel can be found in usb/116057.