xmedk//okno session :: sustainable networks

The okno-session on sustainable networks spreads out over the totality of the xmedk-media ecologies week, from april 20 till april 25.
This workshop week at PAF, St.Erme/FR is the final touch of a month-long research into sustainable meshnetworks. It’s the cherry on the cake of a long research.

At the St.Erme/Okno studio we organise mini-workshops that cover following topics:
– setting up a mesh network with the asus-routers
– flashing the asus routers with linux (kamikaze)
– connecting arduino’s to the asus
– the choice of sensors and connecting them to the arduinos
– reading and interpreting the sensordata with python
– power the network with alternative energy:
– build a custommade windmill for the physical location
– integrate existing solarpanels
– run artistic projects on the sustainable network

pictures of the xmedk-st.erme-sessions in april 2008:
xmedk – day01, 2008
xmedk – day02, 2008
xmedk – day03, 2008
or you can download the pdf of the sustainable networks-report by clicking this link.

A traditional network as the internet has a hierarchical routing structure and is limited in range.
A meshnetwork is decentralised. It has an horizontal structure and a dynamic routing. There is no provider, the network emerges out of a collaborative effort by a bunch of people. The range of a node depends on the strength of its antenna. No immediate sightline is needed, but metal, (concrete) walls or else can disturb the connection between nodes.
Kamikaze is the embedded linux OS that is flashed on the asus. The specific interest of the asus is that it has an usb-port to which an arduino (or webcam, microphone, …) can be connected. Different sensors can be connected to the arduino and via python these data can be processed on the asus.

Some of the sections were researched in Brussels during appropriate workshops.
At St.Erme, we give a summary of what we developed during these last months.
For newcomers we organise some speed-courses on setting up mesh networks and flash them with linux.
The links below give a technical overview on how to install and prepare the meshnetwork nodes. All used software is open source.


The goal of our meshnetwork is to make collaborative artistic projects in public space, looking into the media-ecologies of an appropriate space, whetever it is a rural area or a city.
The participative aspect is very important, as is the use of green energy to make the system a well-balanced, sustainable artistic eco-system.

The output will be a creative, playfull installation that deals with locative information. A non-linear storytelling of the site by sonification and visualisation of its data.

Workshop participants and their specific interests in working with a sustainable meshnetwork:

– pieter: a specific interest in the software POV
– shelli: the self-sustainability in deserted environments
– olu: setting up new emerging tagging systems for blind people
– liz: conceptualize artistic projects in public space
– patrick: eco-hardware (windmill) for powering the network
– junior: develop generative algorithms (with the collected data) that multiply themselves as a virus over the network
– alex: specific interest in the alternative energy side
– gert: make use of the meshnetwork in an (underground) public space project – new ways of storytelling
– wendy: linux, command line. Bring the city to nature by integrating citysounds on the network
– annemie: the participatory aspect in public space projects. Make mobile nodes (human size) and make them self-sustainable.

For building a location specific windmill, we have to measure the windspeed on the spot (best over a period of 1 year).
Often there is a lot of windturbulence. In our case we have to choose an appropriate model for multidirectional winds.
A windmill can be designed in different ways. For a soft wind we need many blades. for a strong wind we need less blades.
In our case, we chose for a combination of Savonius-model to start the mill spinning (the inner part) and Darrieus model to take over the rotation at higher speed (the outer part).
A Darrieus machine is a vertical axis wind turbine. Rotation of the machine is clockwize and it has eliptical blades.
We need a gearbox to bring over the speed of the mill on a 1 tot 10 ratio, connect it to a generator and store the energy in the battery.

The goal is to create autonomous nodes which are self-powered routers and communicate with each other in a horizontal way.
We use routers of the brand ASUS and flash them with the free OpenWRT firmware.
Kamikaze 7.09 (linux) was chosen as development platform as after multiple tests it proved to be stable, easily configurable and accessible for further development. OLSR is used for routing.
Python is put on the Asus to process the sensordata coming from the arduinos and the sensors.

Arduinos, a programmable microcontroller board and programming language which is open hardware / free software are used to get sensor information into the mesh network and read the information from another source. They are connected to the asus via the usb-port. Thus, we use the network as a medium. Sensors (connected via the arduinos or immediately on the asus) can be anything from a webcam to a heat sensor, a piezo, touchsensors and so on.

Participants get an introduction working with terminal (the command line). The basics of C++ and Python programming languages are taught. Thus all hardware/software-steps are covered for understanding the meshnetwork and start to conceptualize artistic implementations.

The last day of the workshop we started to connect sensors, picking up information from the location. Liz and Shelli made a piezo-network running through the building and were picking up sounds from the kitchen and all workspaces.
Wendy started to customize a gardenglove with light and pressure sensors.
Due to a lack of time in St.Erme, we will have to finalize the artistic implementation in Brussels. To be continued.