Inspirational Bits
KATJA GRUFBERG
Master of Science Thesis
Inspirational Bits:
Communicating Technology in a Design Community
Katja Grufberg
Master of Science Thesis MMK 2010:95 MCE 234 KTH Industrial Engineering and Management
Machine Design
Master of Science Thesis MMK 2010:95 MCE 234
Inspirational Bits:
Communicating Technology in a Design Community
Katja Grufberg
Approved
2010-12-14
Examiner
Lars Hagman
Supervisor
Sofia Ritzén
Commissioner
SICS
Contact person
Petra Sundström
Abstract
In any design process, a medium’s properties need to be considered. This is nothing new in design. Still it is found that in Human-‐Computer Interaction (HCI) and interactive systems design the properties of a technology are often glossed over. That is, technologies are black-‐boxed without much thought given to how their distinctive properties open up design possibilities.
This thesis describes an approach using Inspirational Bits to become more familiar with the design material in HCI, the digital material. It is also a way to become better able to share some of this knowledge with all members of an interdisciplinary design team.
Inspirational Bits are quick and dirty but fully working systems in both hardware and software with the single aim of exposing one or several of the dynamic properties of some of the digital materials.
Examensarbete MMK 2010:95 MCE 234
Inspirational Bits:
Förmedla teknik i en designmiljö
Katja Grufberg
Godkänt
2010-12-14
Examinator
Lars Hagman
Handledare
Sofia Ritzén
Uppdragsgivare
SICS
Kontaktperson
Petra Sundström
Sammanfattning
I alla designprocesser måste man ta hänsyn till ett mediums egenskaper. Detta är inget nytt inom design. Ändå förekommer det ofta inom människa -‐ dator interaction (HCI) och interaktiv systemdesign att teknikens egenskaper bara ses över som hastigast.
Tekniken är ofta abstraherad, utan att tillräcklig uppmärksamhet ges till hur deras distinkta egenskaper öppnar upp för designmöjligheter.
I den här rapporten beskrivs ett tillvägagångssätt som kallas Inspirational Bits för att bli mer bekant med designmaterialet inom HCI, det digitala materialet. Det är också ett sätt för att bli bättre på att förmedla kunskapen till alla gruppmedlemmar i ett interdisciplinärt designteam. Inspirational Bits skapas ”snabbt och smutsigt” men är fullt fungerande system i både hård-‐ och mjukvara, med målet att blotta en eller flera av de dynamiska egenskaperna hos digitala material.
Index
1. INTRODUCTION 7
1.1. Mobile Life Centre 7
1.2. Designing Systems For Supple Interaction 7
1.3. Earlier projects 8
1.4. Problem background 9
1.5. Purpose 9
1.6. Method 9
1.7. Delimitations 10
2. BACKGROUND 11
2.1. Approaching technology 11
2.2. Technology as a material 11
2.3. Designing for supple interaction 13
3. INSPIRATIONAL BITS 14
3.1. What is an Inspirational Bit? 14
3.2. Specification of Inspirational Bits 15
3.3. Phidgets 15
3.3.4. What are Phidgets? 16
3.3.5. Whom are Phidgets for? 16
3.3.6. Are Phidgets similar to Inspirational Bits? 16
4. RFID 18
4.1. Common knowledge of RFID 18
4.2. RFID readers 18
4.3. RFID tags 19
4.4. Identity code 19
4.5. Radio frequency 20
5. INSPIRATIONAL BITS OF RFID 21
5.1. Exploration of RFID as a material 21
5.2. The RFID Inspirational Bits 24
5.2.1. BendID 25
5.2.2. RFiddish 26
5.2.3. The diZe 27
5.2.4. inteRFere 27
5.3. RFID properties and possibilities 29
5.4. The Inspirational Bits Workshop 31
5.5. A professional designer’s perspective 32
5.6. Comments to this feedback 33
6. DISCUSSION 35
7. CONCLUSIONS AND RECOMMENDATIONS 37
8. ACKNOWLEDGEMENTS 39
REFERENCES 40
1. Introduction
“The link between the ‘concrete and mathematical engineer’ and the ‘abstract and artistic designer’” said the head lecturer of my university department when he described my future occupation after the program I was attending. And that is exactly what this project has been all about; communicating technology to a design community. Research has been done on how to make technology more tangible for everyone, mainly through different methods and platforms. I have been aiming for something different.
1.1. Mobile Life Centre
The Mobile Life Centre at Stockholm University in Kista is doing research in mobile services and ubiquitous computing [1]. The topic of the centre includes research on consumer-‐oriented mobile and ubiquitous services, spanning all areas from entertainment and socialisation to work and society. The Centre joins forces with local research organization such as the Swedish Institute of Computer Science (SICS) and Interactive Institute and has major partners from the IT and telecom industry, including Ericsson Research, Sony Ericsson, Nokia and Microsoft Research Ltd. Partnerships in the public sector, including City of Stockholm Municipality and Kista Science City secure societal relevance and collaboration with Stockholm Innovation and Growth ensures that results are integrated in the innovation system. In the Centre, this academic, industrial and public partnership will be able to jointly work on strategically important projects that can provide a sustainable growth for Sweden. The Centre adopts a fundamentally user-‐oriented perspective on services for the future mobile life. It provides a neutral arena where researchers and industrial partners together develop:
• New interaction models and platforms that provide a unified interface across different applications and terminals
• Efficient and user-‐oriented methods for developing mobile services
• A deepened understanding of the unique properties of the future mobile life
• A future mobile service eco-‐system where alternative universes for infrastructure, business models and the industry's new roles are explored
• New mobile and ubiquitous services in areas such as pervasive games, social, emotional and bodily communication and new mobile media.
1.2. Designing Systems For Supple Interaction
“Designing Systems For Supple Interaction” is a group within the Mobile Life Centre that is working with developing supple systems [2]. These systems rely on subtle signals;
rich human communication and interpretation strategies such as emotion, social ritual,
provide engaging moment-‐to-‐moment experiences. There are two main factors driving the evolution of supple systems. One is the rapid growth of leisure and entertainment use of technologies and the other is the commercial availability of sensor technology for tracking human expression which has lead to an increasing number of systems attempting to use such technology to provide compelling experiences.
Successful examples of existing supple systems include the Nintendo Wii and the Apple iPhone. Designing and building supple systems is challenging because it is an unfamiliar
“material” for interaction designers but also because it requires a wide range of competencies. The quality of an experience arises in interaction between users and systems. This interaction is in turn affected by a system’s hardware as well as it’s software, and how well they work together.
1.3. Earlier projects
The keyword of earlier projects in the group Designing Systems For Supple Interaction has been suppleness. That a system is being supple means that the interaction between the human and the system should be like a “dance”, without having to make an effort and without having any disrupting breaks due to technical errors. Intention, action and response should be in harmony. Earlier attempts of making supple systems include the eMoto and the LEGA.
The mobile messaging system eMoto (figure 1) made use of the stylus that comes with Sony Ericsson symbian phones, the P800 and the P900 series, extending it with an accelerometer and a pressure sensor to allow users to express themselves physically [3]. By gesturing with the pen, using pressure and movement, users changed the background to their text messages to have colours, shapes and animations resembling their physical movements. Hard pressure and energetic movements with the stylus rendered a strong red colour with a large set of animated small, sharp-‐edged shapes moving in a jerky way. Less pressure and harmonic, wavy movements, rendered a calm blue, wavy background that slowly billowed back and forth. These messages could then be sent to other users to express various emotional content.
The LEGA (figure 2) is a playful and social system that communicates expressions in a group of friends [4].
The egg-‐shaped LEGAs are placed in the hand of one and each and are physically presenting the system.
When facing an object that encourage to reaction, e.g. a craft in a museum, the user expresses oneself by moving, patting and pressing the LEGA in different ways. The signals are stored in an area around the object and when a friend is entering that area, the friend’s object is starting to replay the first user’s gestured expressions.
Figure 1. eMoto
Figure 2. The LEGA
1.4. Problem background
In a design process the design team usually becomes experts on the materials they are working with. However, the technology of the product is often integrated as an external part, a completed craft, which is handling the ”technical stuff”. Later on, this neglect towards technology can result in a conflict between the technology and the rest of the materials of the product.
In general, an industrial designer or an architect has more training in expressing themselves visually, to mediate their expert knowledge and visions, in a legible and concrete way, than for example an engineer. Engineers, in general, must become better at mediating their ideas and expertise in a legible and concrete way.
When designing for supple systems, or any systems, it is important to have a great understanding for the technology used, its possibilities and limitations, so that it does not end up in a conflict with the rest of the materials. The understanding of a technology could be given by an engineer who is able to mediate knowledge in a legible and concrete way. There seemed to be a need for a tool for this purpose. With this research the wish was to come up with a tool that inspires to, and mediate knowledge of, a technology and thereby simplifies the understanding of the technology in a design development.
1.5. Purpose
This project has been focusing on looking at technology as a “digital material”. By doing so the wish was to explore the technology as a material and describe its properties and possibilities. The outcome should be a collection of models that present properties, useful to a design team that needs to investigate a digital material that they will be working with.
The purpose of this master thesis was to find a concrete and legible way to communicate a digital material to a design team and to demonstrate this way by choosing one digital material, in this case RFID, and create a number of models that are pedagogic and that inspires a design team to work with that material. These models should be experienced as easy to grasp, inspiring, playful and/or they should be turning a technology’s limitation into a design possibility.
1.6. Method
The team for this project consisted of four group members, each one choosing a digital material to explore. I chose to explore RFID.
The project started with a literature study of the given subject to gain some knowledge in the field and to see what had been done earlier for the same purpose. The main topic in this study was how to approach technology to get a better understanding of it.
Secondly, the study was directed to how such an approach can be interpreted physically, in practical objects.
The project continued with a brainstorming about what I wanted out of the models, what I did not want and how to get to where I wanted. The project was given the name
Inspirational Bits. Almost throughout the whole project I was coming back to what Inspirational Bits really are.
Phidgets [5] are a set of “plug and play” building blocks used mainly by software designers to quickly sketch up an idea physically. These were studied and evaluated to see if they were anything like what I was after. The aim was to see if there was anything to learn from them, any conclusions to be made about the way they were used, any similarities with the way of using Inspirational Bits, and trying to find what they were lacking in the sense of what I was after.
One and each of the group members chose a different technology to create Inspirational Bits from. This technology was read upon just to get a bit deeper knowledge about it before starting to work practically with it.
The Inspirational Bits were created through an experimental and iterative method.
Every week a new Inspirational Bit was demonstrated, tested and evaluated within the group. Even though I was (almost) an engineer, I had a lot to learn about these different but commonly used technologies that I did not know from before. The results were gathered and analysed and if the Bit was not legible enough, for example, I knew I had to work more with the visual presentation of my model.
The finished Inspirational Bits were tested through a workshop with participants from different design teams and with different academic background. The participants filled out three different questionnaires regarding their experience from the Inspirational Bits during the workshop. A professional designer gave her feedback on the Bits.
1.7. Delimitations
• This project is investigating the subject of how to approach technology to get a better understanding of it in a design perspective. It is limited to investigate computer technology in general and mobile technology in particular.
• The Inspirational Bits are limited to inspire to accommodative movements. I was interested in creating models that provide technology that can be experienced and felt.
• This thesis is only investigating one technology, RFID.
• The technologies chosen to explore and create Inspirational Bits from, had of course a great significance for the outcome.
• Four Inspirational Bits were created from RFID and were therefore only handling an insignificant part of the infinite possibilities the digital material can lead up to.
• The Inspirational Bits created in this project are representing only what has inspired me to create with a chosen technology.
• In the making of the RFID Inspirational Bits only low frequency (LF) and high frequency (HF) have been used.
• Only two different types of RFID readers, each with different size of antenna, have been used.
• The RFID tags used have been of various kinds with different sizes of antennas.
2. Background
As mentioned earlier, research has been made on trying to make technology more available to everyone and some of the research is brought up in this chapter. There have also been practical ways on trying to solve the same problem, “plug and play” building blocks being one of them. A main question in this research has been “What is a material?”. What is it that makes a material a material? What is a technology and what similarities can be drawn between the subjects technology and material? What can be gained by exploring the properties of a technology? By approaching technology as a digital material, by gaining expertise of it, a design team will more likely create technical products for supple interaction.
2.1. Approaching technology
I will describe two different ways of approaching a technology in a design process. The first, and perhaps the most common way, is to collect knowledge about the technology as such. This is usually done sooner or later in any design process and unfortunately it seems as if it is usually later. A theoretical and practical, and sometimes experimental, research is performed which leads to an account of how the technology actually works.
The investigation is looking into its limitations and is examining its strengths and its weaknesses. This is to give rise to a more sufficient knowledge about the technology but also about learning about its limitations and not taking the technology for granted. From these inputs one can decide whether the technology seems to fill the requirements for the particular purpose of the product.
The second way is to approach a technology in perhaps a more controversial way. This way is to work on the supposition of the everyday assumption of the technology and what it can be used for. By assuming the use and limitations of the technology, without looking into it or taking it for granted, one can open up for imagination and explore other possibilities. E.g. to look at what the technology is not meant to do is one way to open up for design inspiration. By doing this, interest and inspiration of the technology can be pushed to the start of the design process, which will hopefully result in a stronger outcome. Trying to find the unexpected in a technology can be a source for inspiration, as can be seen in other brainstorming methods. With this approach one can also study the technology’s limitations as such and make something fun out of them. By not approaching a property as a limitation, but as a source of inspiration, it might be taken less like a constraint. One such approach could also be to increase the limitations to the extremes and see what comes out of that. Another could be to make weird combinations between different technologies and see what that might lead up to.
2.2. Technology as a material
Most of us would agree to say that algorithms, databases, hardware, communication standards, etc. have their own limitations and possibilities. Embedded in each are properties that are more or less fixed, even though the possibilities for combining them are nearly endless [6]. Löwgren and Stolterman describe technology as a material without properties. They suggest that the basic technology has some fundamental
material. Most of these material properties are constantly challenged by new technological breakthroughs and new innovations in how to use the material. They suggest that by consider technology as a material without properties; the design process becomes more open, with more degrees of freedom and therefore more complex. Also, development work rarely starts from scratch; instead, one build using existing libraries, established communication protocols etc., each with their own pre-‐defined properties.
Vallgårda and Redström talk of computational composites, alloys made up of a combination of digital material that impose particular properties [7]. Thus, they explain that it is almost impossible to work with the digital material in its most raw form, at the granularity where technology “handles only voltage according to stored sequences of (practically) discrete voltage levels and maybe input streams likewise of (practically) discrete voltage levels”. Components such as radio, accelerometers, short-‐range communications etc. build on top of this basic level and, in turn, become subsumed into yet more abstract interactive systems, such as PCs, mobile phones, etc. Because of this layering of technology, what can be found in human-‐computer interaction and interactive systems design is that the particular properties of low-‐level technologies are often glossed over.
This appears to stand in contrast to the techniques and approaches that are used in studio-‐based and creative design practices [8]. Through sketches, mock-‐ups and early prototyping, traditionally schooled designers engage in a “conversation with materials”
[9]. In the formation of a new idea the materials are worked with is such a way that they start to “talk back”, revealing new opportunities and challenges. It seems, however, that computing technology is a more complicated material for many designers to work with [10].
Hallnäs and Redström bring up an example of what is a material and what is not. If you take a mobile phone and ask yourself what it is made of, some would say that it is made out of metals and plastics. Such an opinion suggests that the aesthetics of a mobile phone leads down to a box containing some electronic circuits and the rest is a matter of neutral technology. They suggest that a definition of materials in a design process can be tackled by frequently asking ourselves what it is that builds the things. E.g. programs builds a mobile phone in use, thus programmes are material. So the notion of design material is not an absolute notion, but depends on a given perspective. Technology is a material in space and over time [11]. It is not enough to touch and feel this material in any given moment and thereby get to know its properties and potentials; instead; the digital material has to reveal itself and its dynamic qualities when put together into a running system.
One popular approach to supporting developers and designers building interactive systems has been to work on so-‐called support tools. Yet, most of these systems aim to support designers in the processes of visualizing and refining an interaction design (e.g.
[12], [13]), not to handle and explore the digital material. There are also a range of systems that enable designers to rapidly reconfigure the construction of their designs, such as varying the colour, form and overall build of an object, and also visualize previous versions of a design (e.g. [14]), but still this does not provide access to the full range of possibilities the digital material might offer. The designer remains, in some fashion, removed from the actual technology.
The range of plug and play building block solutions provide an alternative, hands-‐on approach to building systems and, in doing so, go some way towards solving the
immediacy problem. These systems, such as Phidgets [5] and Arduino [15], let the amateur hardware developer/maker handle and come to understand more of the digital material’s potentials, making the material more open for reflection in action [9]. But, they still compartmentalize and blackbox basic building blocks, such as RFID. Arguably, this is intended in their design and the basis of their success.
2.3. Designing for supple interaction
“A supple system is doing sort of a social/emotional ‘dance’ with the end user.”
(Isbister och Höök, 2009)
Suppleness is a use quality created by Isbister and Höök [17]. A supple system is a hardware device that uses custom-‐built hardware, sensors, and wireless communication, to interact with end-‐users and create a physical, emotional, and highly involving interaction. Supple systems rely on subtle signals; rich human communication and interpretation strategies such as emotion, social ritual, nonverbal communication, and kinaesthetic engagement; and emergent dynamics, to provide a moment-‐to-‐moment experience.
Supple systems are software-‐intensive, hardware-‐intensive and interaction-‐intensive.
The behaviour of a supple system is defined by its software, the physical by its hardware and the use of a supple system is completely defined by how people take it into use and create meaning with and through the system.
Supple systems is a class of applications that lies in the forefront of technological development and is pushing the evolution in the area of the involved technologies. The evolution is driven by the commercial availability of sensors for tracking human expression, which has lead to a growing number of systems that use those to provide compelling user experiences. Such systems rely on design of the hardware and software together, integrated into specific interaction devices that customers buy as a whole.
Examples include Apple’s iPhone and Nintendo’s Wii.
The quality of an experience arises in the interaction between users and systems. The interaction is in turn affected by the hardware and software of the system. Even seemingly simple artefacts, such as pulse-‐meters, require holistic design of specialized hardware and specialized user interfaces. Each of these factors is equally important: a problem in any one of them can ruin an otherwise great experience.
With this vision, a process will be developed for rapid, integrated, development of supple systems. The focus is set on building so-‐called life-‐style applications, mobile systems that are tightly integrated into our every-‐day lives, as their advanced use of technology highlights the challenges for future applications of supple systems – be it in factories, vehicles, or applications on our mobile phones. The systems developed will explore new materials, such as fabric or paper, integrated with sensors and wireless technologies.
Practically, the keywords to aim for in the experience aspect of the supple kind of product development, is movement, fluency, harmony and coherency.
3. Inspirational Bits
The making of Inspirational Bits has been an iterative process. Throughout this whole process I had to repeatedly go over what I was aiming for, over and over again, since it slightly changed from time to time. This is because this way of thinking was developed by building the Bits and because the technologies used were very different from each other. “What is an Inspirational Bit and how do I create them?” were the main questions being repeated in the iterations. In this chapter I am also taking a closer look at Phidgets to see whether these building blocks are anything like what I am trying to achieve with my models.
3.1. What is an Inspirational Bit?
The Inspirational Bits are models created to tutor, to inspire, to create curiosity, and to leave behind a space for innovative thoughts. An Inspirational Bit unwraps the black-‐
boxed technology, and perhaps twists it again, but in a way that should be easy to understand. An Inspirational Bit invites the one who is using it to get an understanding of the technology it is made from. It shows the digital material as such, it lets the user experience the technology and it opens up possibilities of how it could be used, or what it could be used for, that maybe was not originally the purpose.
Inspirational Bits are made through, what some people would call, technology-‐driven design, because the technology is chosen prior to anything else. The aim of these Bits, however, is to use them for creating products that are not necessarily technology-‐
driven. Different technologies have been chosen and studied carefully to find what properties should be lifted and made tangible. Later on, when a user-‐oriented design team has chosen a technology for their ideas, the Inspirational Bits can help to shape the ideas and quickly point out some possibilities, limitations or other properties that can and be good to keep in mind when working with the technology.
An Inspirational Bit is a model that illustrates a technology. Almost like a sample provided of another kind of material, e.g. of wood, metal, plastic, etc., this model provides an understanding of the properties of a digital material. The model should be tangible enough to inspire and open enough to leave space for imagination of design possibilities. By defining an Inspirational Bit I am pushed to developing the possible paradox of a model that should be semantic and easy enough to understand and at the same time be unmanufactured enough to open up for imagination and for unexpected design possibilities.
The Inspirational Bits is created to let the user experience a technology. By surrounding oneself with the presence of the technology and getting to “feel” it, one might easier be able to play with the idea of what it could possibly be used for. When playing with it the possibilities reveal themselves in a way that might be easier to grasp than through only reading. At the same time it does not necessarily have to be self-‐explanatory in all respects. A design team member, perhaps the one who built it or someone who already experienced it, should be able to fill out the possible blanks.
3.2. Specification of Inspirational Bits
In order to make sure that I was continuously aiming for the same direction I had to make a specification of requirements for the Inspirational Bits. These were my own requirements that I thought would lead up to the best result. During the process these requirements constantly changed but this is what they looked like in the end.
• The Inspirational Bits should be of use for a design team looking for creating innovative technical products. In a design team there is most likely a difference in technical knowledge and the Inspirational Bits should be useful to anyone. Team members with little, or non, technical knowledge can receive deeper explanation from members with more technical knowledge.
• The Inspirational Bits should illustrate property/-‐ies of a technology. Almost like samples provided of other kinds of materials, e.g. for wood, metal, plastics, etc., this model should provide an understanding of the properties of a digital material.
• The Inspirational Bits should be tangible enough to instruct and simple enough to inspire. It should be semantic and easy enough to understand, when facing it, and at the same time be unmanufactured enough to leave space for imagination and for unexpected design possibilities.
• The Inspirational Bits should let the user experience a technology. By surrounding oneself with the presence of the technology and getting to “feel” it, the Inspirational Bit should make it easier to play with the idea of what it could possibly be used for.
• An Inspirational Bit should create an intuition about the use, to some extent. At the same time it should not necessarily be self-‐explanatory in all respects.
• An Inspirational Bit should invite to innovative thinking around a technology and be experienced as easy to grasp, inspiring, playful and/or should be turning a limitation into a design possibility.
• The making of Inspirational Bits should be “quick and dirty”. By overdoing the Inspirational Bits, the focus on the properties might be lost in the appearance of only one possible solution. Another risk is that the attention to the system instead will be drawn to the design of it.
3.3. Phidgets
In computer programming, a widget is an element of a graphical user interface (GUI) that displays an information arrangement changeable by the user, such as a window or a text box. Widgets are basic visual building blocks, which combined in an application hold all the data processed by the application and the available interactions on this data. A phidget is a physical widget and a representation and/or implementation of a GUI widget.
3.3.4. What are Phidgets?
Phidgets [5] are developed to build physical analogue components to software widgets, allowing the construction of complex physical systems out of simpler components (figure 3). Phidgets are a system of low-‐cost electronic components and sensors that are controlled by a host computer via USB. Using the USB as the basis for all phidgets, the complexity is managed behind an application-‐programming interface (API). There are various phidgets available, each having a counterpart class in the API. As each phidget is attached to the host computer, it is made available to control in the API, where its state can be accessed and set.
The Phidget Interface Kit allows input and output interfaces to analogue and digital sensors and switches and is connected to a computer via USB. Up to eight phidgets can be connected to the Phidget Interface Kit. The phidgets all have different properties and sensitivity for different purposes.
The phidget API is what allows systems to access the phidget devices in a high level manner. The API allows the management of devices as they are attached, to subscribe to events and to access the state of the phidgets.
The core API is originally written in C and has been extended to work in numerous languages including .NET and Java. Phidgets can be programmed using a variety of software and programming languages, ranging from Java to Microsoft Excel.
Phidgets are designed and produced by the phidgets company and arose out of a research project in 2001 directed by Saul Greenberg at the Department of Computer Science, University of Calgary [18].
3.3.5. Whom are Phidgets for?
The phidgets are building blocks designed to display how a developed software system works out physically. For example, instead of clicking in the window of the computer screen you push the physical button that you have connected to your computer. They are building blocks suitable for software designers and might not be for designers in general. The usage of phidgets is primarily focused to allow exploration of alternative physical computer interaction systems, but have most notably been adopted by robotic enthusiasts as they greatly simplify Computer-‐Robot interaction.
3.3.6. Are Phidgets similar to Inspirational Bits?
The phidgets are programmed to work within a certain range where the system is considered to be stable. This is to prevent incorrect output from the sensors. Since my wish is to study the properties of a technology, this is not what I am after. The phidgets
Figure 3. Phidgets
are programmed to be reliable demonstration components and does not really open up for imagination, which makes it hard to find new design possibilities.
Phidgets are building blocks. The idea of Inspirational Bits is not to use them as building blocks. They are meant to be fully working systems but only in a way so that they inspire and directs, not in a sense that you can integrate them into another system.
Lifting the programmed constraints from the phidgets could be one way to make them more into the kind of Inspirational Bits that I am after. By letting the sensors react on environment without programmed limitations, I might be able to find design possibilities that are unexpected.
By combining different phidgets in weird combinations might be another way of creating Inspirational Bits out of the phidgets.
4. RFID
The following chapters were presented in the workshop as common theory about the technology. This theory includes the facts that one would normally find doing a quick search on RFID. In the workshop I compared the impact this theory had on the participants with the impact the Inspirational Bits had, in terms of feeling comfortable with working with RFID and being inspired to work with RFID.
4.1. Common knowledge of RFID
Radio Frequency Identification (RFID) is a technology that uses radio waves for sending and reading information at distance from transponders and memories called tags. The technique is great for situations like “where does this product come from and where is it going” and “does this car have the right to pass here or not”.
RFID labels can be placed on products and contain product information and/or work as a theft alarm. They are caped in ID cards/passports for identification and they are casted into plastic pieces and serves as digital keys, and they are used in bracelets on hospital patients where they contain identification, and simple information about their journal and medications. Other examples of areas where RFID is used are in cards for public transports (figure 4) or ski lifts, road fees, price tags, booking systems, libraries, etc.
4.2. RFID readers
RFID readers can have different looks. There are handheld ones (figure 5) and stationary ones. Stationary readers are usually mounted by doors or in portals. The handheld ones are often seen in the hands of shop assistants.
The RFID reader has to use the same radio frequency and protocol as the tags that it is reading. The reader creates a magnetic field and sends out a request for response. If there is a RFID tag within that field, it will respond back to the reader by sending its unique ID-‐code.
Compared to using barcodes, which are also commonly used in shops, the RFID technique does not require line of sight in the communication and is not as sensitive to a situation of blocking dirt. In addition, it is a lot harder to copy a RFID tag compared to a common barcode. The barcode, however, has the advantage that it can be read by any kind of barcode reader, they are very cheap to produce and they are not affected by any interference.
Figure 4. RFID tags in cards for public transports.
Figure 5. A handheld RFID reader.
4.3. RFID tags
An RFID tag consists of an antenna and a radio chip that sends and receives data. The radio part is usually very small and can be produced in many different shapes and sizes, which gives a good flexibility and a broad usage area. The most common tags are in label forms.
There are three different kinds of RFID tags: passive, active and semi-‐passive tags. The passive RFID tags are the cheapest and the most common versions of tags. They have a very simple construction and consist only of an antenna and a unique number that can be sent out a few decimetres. In this type of RFID transponders, all the information is stored in a database. The information stored is bound to the unique ID number. This simple type of RFID can be compared to the function of a bar code. More advanced passive RFID tags have a built in memory that can be subscribed to many times although the memory is fairly limited.
The passive tags do not have an internal energy supply. The reader consists of an oscillating magnet field that induces enough voltage in the antenna for the passive tag to be able to receive an incoming signal and send an outgoing signal containing its number.
The content does not only have to be a number, it can be more complex, like information from an integrated memory. The tag can be small enough to fit in a price tag, to be injected under the skin of an animal or to be implemented in humans for radio wave identification.
The passive tags have the capacity of being read from a distance of a few centimetres up to 10 metres depending on what standard is used and what effect the environment has.
Since the passive tags do not have a built-‐in energy source they can be made very small (figure 6) and easy to apply where space is a critical factor, e.g. under stickers or skin.
The main difference between the passive tags and the active tags is that the active tags have their own energy source, a battery, unlike the passive tags where the energy is induced from the magnetic field from the reader. The energy from the batteries in the active tags is used to send information and to run the components in the tags. The active tags are therefore bigger, need more maintenance and are significantly more expensive to produce. The active tags are used to communicate over a larger distance, e.g. on a car on the motorway, and can reach up to hundreds of metres. The communication between a reader and an active tag is more reliable due to the ability to have an active session with the reader. And because of the higher level of voltage, the signal can pass through decelerating materials like liquids. The batteries in active tags can last for up to ten years. Bigger memories can be integrated since the size is usually not an issue with active tags.
Semi-‐passive RFID is a hybrid between passive and active RFID. The difference is that the integrated energy source is only running the microchip and other internal components, and not the sending of signals. Therefore the battery lasts longer. The tag can log data over time and send it whenever a reader asks for it.
4.4. Identity code
Every tag has a unique identity, which consists of a code of up to 20 characters. This
can also contain a memory in which you can store information, normally with a size between 2 – 2000 bytes. It is possible to increase the amount of memory but the cost of the circuit would be significantly larger.
4.5. Radio frequency
For a reader and a tag to be able to communicate they have to be “speaking the same language”. In RFID this means that the reader’s antenna and the tag’s antenna have to be tuned to work on the same frequency. About 30 different frequencies are used and the four most common ones are:
• Low Frequency (LF) 125 – 134 kHz
With this low frequency the waves can easily penetrate materials like water or even metal. Therefore this type is used for tags in tissues of humans and animals.
• High Frequency (HF) 13,56 MHz
This is a frequently used frequency band suitable in many sectors of applications. It is still reliable and can penetrate some materials and the range is longer.
• Ultra High Frequency (UHF) 862 – 960 MHz
The frequency band is fairly tight and the communication can easily be disturbed by other units, like a microwave oven for example. Cannot penetrate other materials.
• Ultra High Frequency (UHF) 2,4 GHz
The frequency band is very tight and the communication can easily be disturbed by other units, like mobile phones for example. Cannot penetrate other materials.
Every circuit is also run by a protocol, which differs depending on the system. The protocol is controlling how the communication between the reader and the tag is to be done. It is also controlling that a collision of data will not occur. Thus, a RFID tag can only be read by a reader that is using the same frequency and the same protocol as the tag.
4.6. Range
The range can vary from a couple of centimetres up to hundreds of metres. This distance, in which a tag can be read, depends on four major factors:
• The antenna size, both of the reader and of the tag
• The frequency; the electric current that the tag can induce from the magnetic field of the reader
• Interference, from other radio frequencies or absorptions from surrounding materials
• The type of tag; whether it contains a battery or not.
