spench.net

An old Nokia mobile with DCT-3 firmware (for network monitor mode) is required. The phone needs to be connected to a computer via its FBUS serial interface, so some level conversion hardware is also required. Since most modern laptops do not have an external serial port, an RS-232 to USB converter is also a good idea.

This experiment involved acquiring CellID and signal strength information from the GSM cellular network, tracking one's position while acquiring this data, and finally presenting it nicely. It is summarised in the following pictures (full details are described in the sub-sections found top-left):

Hardware:

Mapping position and signal strength measurements:

Navman GPS receivers, and the like, are great, until you actually want to use their received GPS data on a computer in real-time. Luckily there are plenty of resources to do this (NavmanUnlocked, the forum, MioPocket, GPSPasSion and GPSUnderground). In addition, I recommend SiRFTech for GPS testing. There are many tools available too, such as SSnap, which is extremely useful to track registry and filesystem changes. This is especially good when creating a one-off .reg file that you can import after a hard reset to restore the state of WinCE (in particular Bluetooth pairings).

Here, I give a quick guide to turning a Navman S150 into a Bluetooth GPS receiver that one can use with gpsd on a Bluetooth-enabled computer.

Behold the trusty S150 running WinCE Core 5 and PNADesktop (which is launched from \Program Files\Navman\appstartupsec.ini - the other apps, e.g. SmartST, are manually disabled):

A little something I made in my spare time:
(More details coming later...)

The following pages detail my WiFi adventures:

• WiFi Antennas
• Atmel at76c503a Wireless USB Adapter

This started with my desire to build a Woktenna.
Of course you can't very well put a PCMCIA wireless card at the focal point of a cooking wok!

So the alternative is using a USB WiFi adapter that can hang on the end of a USB extension cable and
introduce minimal analog signal loss and USB is digital!

Despite the fact is says "Linux compatible" on the box, it wasn't immediately possible to do what I wanted to do,
which is: monitor mode!
With monitor mode, I'd be able to point the woktenna around and pick up the beacon frames of distant APs.

I found two drivers available for this device:
one over at BerliOS,
and the other at SourceForge.

I have made the following WiFi antennas:

Cantenna

Made two, same design for both.
Gain is good: ~12dB.

Thanks to the generosity of Aras Vaichas, I came into possesion of an old (1992) 60x8 dual-colour LED display. As it was just the display itself (no manual, instructions, software, etc) I set about reverse engineering the board. Using my multimeter I re-created the schematic for the board and found all the relevant datasheets online. Having figured out how to talk to the display, I interfaced it via the parallel port and wrote some control software for it. Once I could display various test patterns (multi-colours sine waves), I 'net-enabled' the software so that the display could be controlled over a network via UDP packets - the resolution is so low that the entire LED configuration fits into a single packet! Finally, I wrote a plugin for Winamp that streams the frequency analysis of the playing song to the display, which produces results like this:

My major project for PHYS2601 'Computer Applications 2' in 2003. You can read the actual report (PDF) or report (broken Word-exported HTML), which details the design, electronics, firmware and testing.

Dr John Smith told me about these types of receivers, so I thought I'd build the bare-bones-basic one.

Unfortunately it's not possible to use it anywhere near urbanised areas due to the 50Hz mains interference 'hum' that swaps out mother nature.