The Deliverator – Wannabee

So open minded, my thoughts fell out…

Seattle Wireless Hacknight – 11/22/06

Posted by Deliverator on November 24th, 2006

Most of the guys at Hacknight spent the evening working on a bunch of Arlan 900mhz radios purchased from Ebay. These are wireless devices that predate the 802.11 standard and date from about 1994. The devices all came in access point mode, but some clever use of the Internet Archive revealed a method to convert them to bridges by applying a particular sequence of firmware upgrades and downgrades. A few of the devices were bricked in figuring out the proper process, but it seems like most of the kinks have been worked out now. The Arlan devices only cost about $20 each (compared to modern 900 mhz devices which cost 400+), so nobody is too discouraged about a few bricked ones. The intention is to use these to test the feasibility of linking nodes which for whatever reason can’t be linked with 2.4 ghz radios, such as near line of sight scenarios where dense foliage or a building might separate two isolated nodes. If a link can be established using these old, slow (.5mbit) 900mhz devices, then it should be possible to simply swap in newer (read – expensive), high speed 900mhz gear. At $20, it is a cheap way to test the viability of a link and hey .5mbit is useful in its own right.

A nice guy named Joseph stopped by our table and asked us about what we were doing. Turns out he does a lot of low level system designer/engineer and has a lot of experience with the Motorola 68k family of processors which the Arlan devices use. He is going to try and stop by next week to disassemble some code and provide some more details on the boot process. Hopefully, he might be able to find a way to debrick a few devices, or find an easier way to convert them over to bridging mode. He used to work for Psion and we talked for a while about my Psion Netbook Pro, Nokia 770 and the upcoming 870 (presumed name). He was very disappointed over what has happened to the company over the years, in particular the switch from the EPOC OS (arguably the most stable, robust OS ever featured on a palmtop) to Windows CE.

Ken tested some high power, 400mw mini-pci 802.11g radios from Ubiquiti Networks using a Soekris board. This is a particularly neat radio as it is high power, has excellent receive sensitivity, uses an Atheros chipset supported by the MadWifi driver under Linux and has both MMCX (yay!) and u.FL connector. MMCX is considerably more robust connector, mechanically than u.FL. It also appears that this card is available with an optional SMA connector, which would be better yet. Ken has some doubts as to whether two of these very high power cards will run happily in a low-power Soekris boards, but I expect these cards will find a lot of useful niches.

Matt Westervelt
and I both purchased new lenses for our respective Nikon DSLRs, but have yet to receive them. I purchased a Sigma 30mm F/1.4 and Matt purchased an MC Zenitar 16mm F/2.8 fish-eye lens on eBay from Kiev Camera. This Zenitar fish-eye is one of the cheapest wide-angle lenses currently available at around $150. The lens is made by KMZ which has been making all sorts of optical products since WWII. This lens is strictly manual and the build quality is probably about what you would expect, but for $150 it is probably the cheapest way to experiment with a fish-eye lens. People seem to have a lot of fun with this lens and Flickr has some interesting examples of what can be done with it. I might pick one up once my budget has recovered somewhat from all my recent camera related purchases.

More pics from Hacknight available in the gallery.