As a follow-up of the spreadgun performance in 2008, SMSlingshot is an extension of VR/Urban's digital intervention activism. The installation features a handheld digital slingshot device for spreading information on public screens.

Having the conceptual idea of the device already in mind a year before, white nights 2009 at Kim? (Riga) was for us the right opportunity to actually create, finish and present our first prototype of the mobile textgun.
Like the spread.gun installation for the media facade festival 2008 (Berlin), the SMSlingshot is a truely tangible, embedded interaction device for linking digital data with people acting in urban (real) space.

The Concept

Because of the increased commercial interest of paving public space with digital advertising screens the need for an accessibel intervention devices seemed obvious and necessary. The wish and habit to comment (tag) the surrounding world is also an ancient and still vivant phenomena we try to preserve. Our concept of VR/Urban aims for claiming back urban space and and give the inhabitants a tool for occupiing urban screens. People shall not
only remain as a passive audience, they must obtain the
privilege and beside that the right tools to create their
own multimedia content in the streets. The more and more
mushrooming media facades, LED supplied walls and huge
projections are interesting and worthy technical innovations
for the people, but in contrast to the old fashioned posters
in the streets, it is nearly impossible to create own content for these facades or even hang up your digital video.

The SMSlingshot is an autonom working device, equipped with an ultra-high frequency radio, hacked arduino board, laser and batteries. Text messages can be typed on a phone-sized wooden keypad which is integrated in the also wooden slingshot. After the message is finished, the user can aim on a media facade and send/shoot the message straight to the targeted point. It will then appear as a colored splash with the message written within. The text message will also be real-time twittered - just in case.

Prototyping

For the hardware and caseing design we made several mockups to find ergonomic shapes, sufficent space to fit in the electronic parts and architypical form of a slingshot. Because of the high amount of technical equipment stuffed in the slingshot, we had to try different model sizes and various arrangements of the parts.

Next to the modelling process a lot of sketches have been done in order to foster certain elements in the mockups that we were not able to model in a physical manner. The layout of the keypad had to be shrinked down to a minimum of space, and the Arduino PCB had to be hacked down to become as small as possible.

To get the geometries of the slingshot case from the computer screen to the real world, we used a five axe milling machine to cut the shape out of a plywood block. For us it was especially important to use real materials and real shapes. Wood has so many tactile and haptic qualities and is the typical material to built slingshots from. For prototyping purposes we created two models, one with a lot of free space inside for having various opportunities to place the components and one with less assembly options and tighter fit to avoid the components from bouncing around inside.
For creating the milling opereations we used the Cimatron8 software.

YOU as a designer might already know: Nothing fits at the first time ;) So Boscij needed to have his hands on the readymade prototype. Some coffee and cigarrets later, everything fitted slick and smooth.

Technical Prototype

In the early phase of the SMSlingshot development, it was not quite clear how the text entry should be done. We experimented with a jog-dial (rotary encoder), arrow keys, virtual cursor, matrix keyboards, etc. The problem of text entry is not a trivial one, since it is a compound problem. One has to consider the software, hardware and also the human itself. Should the user type with one thumb, thumb and index finger, index finger, two index finger or two thumbs? Also the software needs to consider the different modes. Mobile Phones for example use predictive methods to suggest words one might want to type. But if you consider implementing automatic text completion new problems arise. No one of us can speaks Latvian and licensing a prediction algorithm would definitely blow our budget, not to speak about memory problems.

However, most of the technical problems are like in every software project self made. So we kept to the agile maxime functoning prototype over never ending planning and discussing. The development process anyway is iterative, so what?
In order to manage the iterative process, most of the slingshot parts existed multiple times. We had one development system and a working system. Ultimately one should have three concurrent systems for development, testing (release candidate) and deployment (the bug free version of a system). However, budget was short so we had to compensate that with braveness and ingenuousness.

Fitting all the electronic parts into the slingshot was quite a difficult task. Especially the power sources took a lot of space within the case.

Having the SMSlingshot ready to sling, bags were packed and taxi ordered.

Our intervention took four hours and people loved it. It was very nice to see how people handled the artifact. It was a mixture of familiarity, intimacy and expresivness. The act of occupying a part of the facade with your personal virtual message produced a lot of joy for most of the people. Also the act of getting the device, typing a message, pulling and releasing the slingshot and watching the impact of the splash followed a development of suspense like one might find in a story of a book. Even twists and turns were observed. :)

For now we would like to thank all the people who mad this possible. We really liked the venue in Riga an we will certainly come back.