Freeform explores the dynamics of interaction of participants who manipulate a set of physically independent objects that are augmented with the capabilities to communicate wirelessly between them. The generation of visuals on a central display is influenced by the relative positions of the objects, their proximity and group formation. The objects interpret these properties from the wireless exchanges between them, and are represented on the display by soft white tentacular lines interconnecting the nodes, lines that slowly fade, leaving traces of the history of interaction. The system interprets a cluster of objects physically separated from the rest as sharing a common property, a common space, and visualize their relationship by drawing colorful patterns between their virtual nodes on the display. The graphical representation does not aim at creating an exact copy of the network in physical space, instead it visualizes what is perceived by each individual module based on the wireless signal that connects them. Instead of hiding the wireless infrastructure, it brings forth the intricate properties of the network of objects to generate its pleasing graphical content and explores some interesting possibilities for mapping physical interaction to digital information.
hardware
The body of each object consists in a flexible semitransparent latex skin surrounding their electronic core. Each uses an Atmel ATmega8L microcontroller with the Arduino platform. They are powered by 22 AAA batteries through a 3.3v VPack boost converter from Bodhilabs. The microcontroller controls the Maxstream XBee module, a 802.15.4 compliant RF module, to connect wirelessly to proximate objects and sense the signal strength with a simple protocol.
A host consisting of an XBee module and a USB to serial converter receives the data from the free objects and sends it to the USB port of the host computer.
A host consisting of an XBee module and a USB to serial converter receives the data from the free objects and sends it to the USB port of the host computer.
software
Processing receives the data from the host object, separates the incoming information based on which object sent it, and generates virtual nodes that reflect the physical objects. The position of the nodes in the display is based on the received signal strength of each module that creates a signal space, which is an approximation of their physical position. The connections between physical objects are represented by soft white lines that show if the two objects are exchanging data. The software evaluates the signal strenght between each objects to detect the presence of clusters in the physical space. When two or more objects are found to form such a group, their connecting lines create coloful patterns constrating with the other associations. A hisotry of the interaction is kept as layers slowly fade to be replaced by new ones.
