====== RKNFG, salzamt, september 2012 ======


During a summer residency at Salzamt, Linz and within a project called Expand, Explore, Expose I developed a piece RKNFG that explores and exposes a part of 'hertzian' space. This term describes a collection of wireless signals - electromagnetic waves, that our electronic devices radiate and fill our environment with. RKNFG analyses WiFi signals and uses this as a parameter in design of spaces. The traffic through an access point is scanned and the amount of traffic is used to determine whether the space is going to 'grow' or 'shrink'. Users can interact with the installation through their smart phones or other portable Wi-Fi enables devices.

  * video from the exhibition opening http://vimeo.com/50707514

===== interaction scheme =====

{{:rknfg-interaction-scheme.png?400|}}
===== technical details =====

cubicle (wood base + stretchable fabric sides) + linear actuators + arduino + laptop running airodump-ng on Debian 
==== hadrware ====

  * the structure:
         - plywood board base, 1x1m
         - plywood board top, 1x1m
         - white stretchable fabric (1.5x3m) fixed on 3 sides

{{:img_20120906_152720.jpg?nolink&200|}} {{:img_20120907_231737.jpg?nolink&112|}} {{:img_20120909_212544.jpg?nolink&112|}} {{:img_20120909_212433.jpg?nolink&200|}}

        - two Firgelli linear servo actuators, [[http://www.firgelli.com/pdf/L12_datasheet.pdf|L12 datasheet]]

{{http://www.phidgets.com/images/3541_0_Web.jpg?nolink&200|}}

  * controls:
        - Arduino Diecimila board
        - laptop: scanning and sending data to Arduino
==== software ====

  * [[http://www.aircrack-ng.org/|aircrack-ng]], scanning network traffic (looks up the traffic on a specific BSSID, writes a dump to a .csv file)
  * [[extended-python-arduino-api|extended-python-arduino API]] firmware for the Arduino, with the associated [[arduino-py|arduino library]]
  * python script [[motors-scanner-test-1|motor-scanner.py]]: reads the .csv file, calcutlates the next position of the linear actuators based on the difference in the number of packets since the last calculation

  * more details: [[salzamt|RKNFG development]]

===== HOWTO =====

  * use this [[startup]] script
or
  * start aircrack scan 
 <code bash>/etc/init.d/networking stop # stop network manager
killall wicd # if using wicd network manager for debian
airmon-ng start wlan0 # start airmonitor on your wireless card; to check the name of the card run $ sudo ifconfig
airodump-ng mon0 # see available networks, find bssid of the network you want to scan
airodump-ng --bssid xx:xx:xx:xx:xx:xx -w /path/to/your/folder mon0 # dumps the scan to a file in  /path/to/your/folder/
</code>
  * in a separate terminal, run the python script
<code bash>python /path/to/your/folder/reading.py</code>
  * when finished, stop airmon-ng
<code bash>airmon-ng stop wlan0
airmon-ng stop mon0
</code>