h3. Barcodes for spatial markup and control
“Spotcodes”:http://www.highenergymagic.com/spotcode/index.html use a very “simple circular barcode”:http://www.highenergymagic.com/spotcode/symbols.html, to mark objects for interaction with a camera equipped phone.
* Requires a “small application”:http://www.highenergymagic.com/spotcode/download.html running on a Series 60 phone to scan barcodes with the built in camera
* Each barcode can currently store 42 bits of data using technology modified from iris tracking and wavelet technologies (as far as I understood)
* Potential for more data by increasing the number of rings, but current setup is a compromise for low quality cameraphone cameras
* The mobile phone application can determine position of phone relative to barcode by the elliptical distortion of the circle, could perhaps be used for quite accurate tracking with multiple spots
* The phone application communicates via bluetooth or gprs, using the barcodes as triggers for interactions
* It’s coded ‘close to the hardware’ to use the video input to do barcode calculation in realtime: Java/Symbian apps don’t have an API to realtime video input
* In use commercially via “Bango”:http://www.bango.net
h3. Bluetooth mapping
“Reverend Rat”:http://www.spy.org.uk/ratblog/ demoed his 10 Watt bluetooth receiver, 10 times more powerful than a 35 mile 802.11b receiver, and 100 times more powerful than a Bluetooth dongle.
Not particularly interesting in itself, but using it from a high vantage point he might be able to map out usage patterns in urban areas, or track the flow of people and devices.
h3. Some photos
p(caption). Nice impromptu public markup
p(caption). Anil demonstrates test barcodes for spotcode
p(caption). Reverend Rat discovers Bluetooth devices
p(caption). Celia and Rod
Some of our ambitions were:
* Investigate transformative use of space and place
* Address gaps in infrastructure: access to standards, material frameworks and technology
* Instigate a triangular network: tried and trusted network practice
* Pursue research and practice, less engineering
* Explore relationships between media, gaming, locative, mobile, visual media
The discussion is continuing, and the next informal meeting of participants is happening at ISEA 2004.
h3. Some pictures
!/images/creativecrossings01.jpg(Creative Crossings workshop: Graham Harwood and Michelle Kasprzak)!
!/images/creativecrossings02.jpg(Creative Crossings workshop: Jo Walsh and Gabe Sawhney)!
!/images/creativecrossings03.jpg(Creative Crossings workshop: Rachel Baker and Tapio Makela on the 19 bus)!
!/images/creativecrossings04.jpg(Creative Crossings workshop: Tapio Makela on the 19 bus)!
!/images/creativecrossings05.jpg(Creative Crossings workshop: Finnish Ambassador’s residence, Battersea)!
!/images/creativecrossings06.jpg(Creative Crossings workshop: Finnish Ambassador’s residence, Battersea)!
!/images/creativecrossings07.jpg(Creative Crossings workshop: Finnish Ambassador’s residence, Battersea)!
!/images/creativecrossings08.jpg(Creative Crossings workshop: Finnish Ambassador’s residence, Battersea)!
!/images/creativecrossings09.jpg(Creative Crossings workshop: Finnish Ambassador’s residence, Battersea)!
It’s possible to use the “GPS Map 60c”:http://www.garmin.com/products/gpsmap60c/ in an old “Marimekko bag”:http://www.marimekko.fi in a mobile phone pocket just small enough that the aerial sticks out. In this way it can be placed in windows of buses or cars without it sliding around, and I can walk around without looking like a geek or getting mugged.
!/images/urbangps03.gif(Rendered trail of three months walking in Oslo)!
In short, GPS doesn’t work well in dense urban environments like most European cities. This is from the perspective of a pedestrian confined to the pavements (sidewalks) and public transport. From a few experiences whilst being driven around, it seems to work well in a car, probably because of the clear sky area available in the middle of the road. Inclement weather and green trees also seem to be problematic.
In these last few months, attempting to record a good quality database of tracks to geo-locate my photographs, I must have looked really odd. Face in device, stopping on street corners, stopping in the middle of street crossings and scrambling to grab the front seat of the bus. Discovering that GPS doesn’t just passively work is a great disappointment and my dataset is clouded with gaps and anomalies.
h3. Some other observations
* Fast turns when using public transport or car result in wild deviations: re-aquiring satellites is the problem
* Need a road that aligns with at least 4 satellites to get an acceptable track, anything else and the errors can accumulate
* Glass buildings can result in ‘reflections’ of position, eg jumping to other locations due to reflected signals
* I sit on the outside or front of buses: to get a wider expanse of sky area: I am constantly aware of sky cover
* The relative position of satellites is beginning to have an effect on the side of the street that I walk on
* Walking in the middle of the street: had a couple of near misses with cars – the moving map is just too engaging
* I would like an explanation of the lost track calculations: this device seems to use the last-known bearing and velocity to guess new tracks when the signal fails. This is very unreliable and problematic as it fills the map with phantom trails
* The track can be more useful over time than the (base) map: it shows my personal space and personal routes, I know where I have been and can use it to retrace routes or places. Popular routes build up in blackness and thickness. Home area becomes an abstract scatter plot of routes, but it’s very familiar
* Stored waypoints are really useful for getting large, general bearings on location: zooming out and seeing a relationship to two known landmarks can be really useful in an unknown area
!/images/urbangps04.gif(Rendered trail of two weeks walking and public transport in London)!
!/images/urbangps01.jpg(GPS receiver resting on the top deck of the number 4 bus, London)!
!/images/urbangps02.jpg(GPS receiver in the window of a train, Oslo)!
Designing with Web Standards
Taking Your Talent to the Web
Jeffrey Zeldman. A fantastic how-to book for designers looking to get involved in web publishing and design. Takes the reader through writing, usability, architecture and technical tips.
amazon.co.uk / amazon.com