Originally I scanned with a ASUS EeePC 900 netbook which was attached to 5 wires to work properly.
I attached 2 ALFAs, a GPS receiver, an USB hub and the 12V lighter power supply.
It lasted at least 1.5 minutes after POST to enable all scan functions!
Overall it made huge effords and I decided to develop my own solution with my Raspberry Pi.
The reason why I built this bot is that it’s quite small and it maintains a low profile. The chance that you get asked what you are actually doing is quite low. With this mate I also climbed up to Rank 1 on Wardriving-Forum board.
Measures and WeightWith a length of 103mm by 105mm and a height of 36mm, the wardriving bot is a slight and light portable fellow.
It weighs 370 grams and is as light as a feather compared to laptop computers!
You can even put it in your jacket while buying gifts for christmas! ( tested ).
StartupAll functions are ready to run within approx 15 seconds. This is possible by installing a lightweight OS which is based on Debian wheezy. Autostart scripts allow you to start scanning just after pressing the power button.
Runtime and RechargingMy ScanBox has a (Sanyo Enerpower 18650) 1-Cell Li-Ion rechargable battery integrated, which enables the Raspberry to power itself for 1.5 hours without external power sources. Recharging is done by plugging in the USB cable into a 1A USB charger if you want to scan simultaneous. If not, you can recharge it at common USB ports.
I also built in a protective circuit to prevent overcharging and deep discharging.
Increased lifetime is achieved by adding more cells. With 4 cells you can get up to 6 hours of runtime with only one charge!
You can read out current battery levels through a MCP3008 IC.
LEDsThe wardriving bot got 3 LED which informs you how many APs are in your range.
Additional to that it got a power LED and a GPS LED which informs you about fix.
# Condition Encryption Red WPA/WPA2 Amber WEP Green OPNThe power LED starts blinking if the battery level is low.
The GPS LED stops blinking if a 3D fix is found..
WiFi / AntennaMy ScanBox is powered by an 2W ALFA AWUS036NH which is based on the RT3070 chipset.
Because it‘s more sensitive than OEM WiFi adaptors, you get the most out of your box.
The external RP-SMA port enables you to connect your own antennas, if you want.
GPS & TimeThe GPS module is brought by a wired Navilock which fits perfectly into the ScanBox.
To keep the correct time a DS1307 I2C Real-Time-Clock is added to the Raspberry.
USB PortsOverall I got 2 USB ports on the ScanBox which have the following functions:
Type A Plug: Connect any USB media or an additional ALFA WiFi module to raise your range. If two ALFAs are recognized, the kismet configuration splits channel scanning automatically.
Type B Plug: Used for charging purposes.
Upload FAQAll files will be transmitted automatically to attached USB devices. It also synchronizes all files which were created before. If you don‘t plug in any USB device, the ScanBox will store files in a local folder. After booting the Box with a pen drive plugged in, it will start synchonizing your database.
The interval between saving is 300 seconds by default.
RangeCompared to the EeePC with 2 ALFA modules, the ScanBox sticks with 90% of the access points while using 1 ALFA only!
This is quite effective. The wardriving bot even found a couple of WLAN which the Netbook missed.