Thursday, April 21, 2011

Homade Wardriving Rig

I am an avid wardriver. Wardriving is the act of using a WiFi enabled device such as a laptop to find wireless access points. The act itself is not illegal. It only becomes illegal when you associate with someone's access point without their permission. This is considered "stealing bandwidth". I only scan for the access points and never connect to them. I find it interesting to see what others name their networks and also to see how many I can find. So, I set out to build a directional antenna that I could mount to my roll bar on my truck in order to achieve a greater scanning range.

At first I built a cantenna from a pringles can. The results were more than lacking. I did a little research on the subject and decided on a hybrid mix of a yagi and parabolic antennas.

The outcome is quite nice performance wise. Also the resulting antenna is not obtrusive but ascetically pleasing.

Thursday, April 14, 2011

Bluetooth + CB

I realize that the CB antenna and Bluetooth devices operate at different frequencies. This was just one of those "I wonder what would happen if" moments.
The other day, I was digging through my electronic parts and I came across my bluetooth usb dongle. Instantly I was reminded of why I bought this thing. I was going to use this little beauty to send pictures from my phone to my laptop a couple of years ago. I did for a while. The program I used was called BitPim. It was just something I came across while surfing google one day. The reason it was in my parts box is because of the poor range of Bluetooth. Now you must realize I am a fan of wardriving (the act of using a wifi capable laptop to scan for access points while on the move). Then, the idea of bluetooth wardriving came to me. Today most cell phones have bluetooth built in. If the cellphone is in discoverable mode, any laptop with a bluetooth adapter can scan for these devices. I have already used my linux laptop to scan for wifi signals so I decided to use the usb dongle to scan for bluetooth devices. I quickly realized that you have to be pretty close to a cellphone in order to find it via bluetooth. At this moment, I happened to look out the window and notice my cb antenna mounted to my truck...PERFECT! I set my laptop to loop through the "hcitool scan hci0" command. In linux this is how I scan using my bluetooth dongle.

I decided that this would be the perfect candidate to increase the scanning range of my laptop. I just had to figure out how to go about achieving this. So naturally, I took apart my usb dongle. I found the internal antenna and was surprised that it was a tiny piece of metal. So I soldered a copper wire to the antenna and cut a hole in the plastic case for the wire to exit the devise. Next, I added a small alligator clip to the end of the wire. I unhooked my cb radio from the coax cble inside the cab of the truck and clipped the alligator clip to the copper lead. Instantly I heard the ping of my laptop. Success! The laptop had detected my android phone in the house! The house is about 90 to 100ft away from the truck. I was amazed at the distance the phone was detected at. After a drive to McDonalds, I found 27 bluetooth enabled devices set into discoverable mode. And the rest is history.