MARCH 2015
The Sensors Behind the Oculus Rift
Bare Conductive Develops Revolutionary
Libelium’s Smart Factory Solution
CONDUCTIVE
PAINT
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CONTENTS
SENSOR TECHNOLOGY
CONTENTS
4
TECH REPORT
Libelium Enables Smart Factory Integrated platform utilizes sensor tech and Cloud access
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COVER STORY
Turning Surfaces into Sensors Bare Conductive develops revolutionary conductive paint
EEWEB FEATURE
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Enter the Rift Extraordinary new virtual reality headset from Oculus
EEWEB FEATURE
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WobbleWonder An Oculus Rift add-on straight from the Maker community
We essentially asked ourselves if we could paint or print an electrical infrastructure on different surfaces...pg. 14
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SENSOR TECHNOLOGY
SMART FACTORY Reducing Maintenance Costs and Ensuring Quality in the Manufacturing Process Smart Factory solution with Waspmote and Microsoft Azure combines efficiency and regulatory compliance with sensor technology and Cloud access. Established in 1959, Polibol is a leader in the flexible packaging sector. With 150 employees and revenues of over 40 million Euros, Polibol has a worldwide reputation for technological innovation as a flexible packaging printer and converter. The Polibol group operates two plants, one in Zaragoza and one in Madrid, with 18,000-square-meter facilities. The company’s chief activity is the manufacturing of printed coils and aluminum-laminated plastics for use as flexible packaging for food and consumer products.
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TECH REPORT
Bird’s-eye view of Polibol’s Zaragoza plant.
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SENSOR TECHNOLOGY
A
s a manufacturing company, Polibol operates various production lines that incur a number of critical processes. In some cases, controlling the air temperature near machinery on the factory floor is essential; in others, gas must be monitored to keep compliance within authorized levels of concentration. Packaging for the food industry is subject to demanding health legislation regarding food safety and hygiene, as well as compliance with international standards, such as ISO-22000, for which Polibol is certified. Compliance with FDA regulations means that it is crucial to maintain a high level of quality control throughout production. Another important consideration for Polibol is how to optimize processes, in order to reduce costs while ensuring quality. Manufacturing controls require continuous measurement of environmental variables, making this ideal terrain for wireless sensor technology (WSN).
Customer Case: Machines, Sensors, and the Cloud Libelium, an open-source sensor platform provider, designed a specific application for Polibol using their Waspmote Plug & Sense! network and the Meshlium gateway. The solution monitors critical processes, environmental variables throughout the factory, parameters that affect product
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quality, and working conditions. With Libelium sensor network technology, Polibol monitors air temperature around printing machines and in pipes, light intensity on the final products, and CO2 concentration in the workers’ area and in real time, using a PC, tablet, or smartphone and an Internet connection. The integration of Libelium sensor technology with the Microsoft Azure Cloud platform allows data from Libelium’s sensor nodes to transmit directly to the Cloud, for analysis and use by Polibol in a number of applications.
How it Works: Sensors in the Factory In the Polibol factory, the printing process is performed on printing machine units that print color on color to form the final image. In the body of each printing unit, a mixture of colored ink and solvents keep the ink liquid and the coil impregnated. The product then travels through a drying tunnel to remove the solvent, leaving the dry pigment. At this point in the process, it is crucial to control the drying temperature, because if the ink is not completely dry, the next printing unit will blur and smear the ink, ruining the impression and resulting in complete rejection of the production. Printing is high speed, more than 200 meters per minute. In addition, temperature also affects the elasticity of the materials (polyethylene, polypropylene, polyester, polyamide, PVC and aluminum) during
TECH REPORT
Libelium’s sensor solution helps Polibol in four key areas.
Manufacturing controls require continuous measurement of environmental variables, making this ideal terrain for wireless sensor technology (WSN).
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SENSOR TECHNOLOGY
the manufacturing processes, which may affect the ink if not properly applied. Likewise, temperature influences the laminating process as well. Laminating consists of pressing together up to three layers of aluminum or plastic material to obtain a sum of properties essential to each final product component: strength, impermeability, visual impact, sealing, etc. Between each layer of material and each layer of adhesive, the drying temperature must be monitored to prevent delamination of the final product.
Monitoring Temperature inside pipes with Waspmote Plug & Sense!
Temperature control also requires a high sampling rate and high rate of accuracy in the readings. Because of all the above, the cost of maintenance of these printing and laminating machines may be high. Ensuring the right temperature control not only reduces the rejection of products, but lowers the maintenance costs. Humidity sensors are necessary because humidity influences the flexibility of some plastics with a high hygroscopic coefficient, such as polyamides and watersoluble synthetic polymers. Humidity can alter the behavior of the printing inks and affect the final image quality. Light sensors are needed to maintain a constant luminosity, and are calibrated
Temperature and humidity monitoring using Waspmote Plug & Sense!
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TECH REPORT
for color analysis, since color looks different depending on ambient light. Sensors that can capture volatile organic compound (VOC) readings are very important. In the process of printing and laminating, different types of solvents are used that volatilize during the drying process. Legislation has established regulations to ensure that any solvents that may be retained in the ink or adhesive that come in contact with food remain below minimum levels of tolerance. Environmental rules state that evaporated VOCs from the solvents must be captured, recycled, or destroyed in a controlled manner, to keep them from polluting the atmosphere. Sensors measure VOCs and ensure compliance. Finally, noise sensors monitor working conditions in the factory.
Hardware is Easy The hardware configuration for Polibol consists of four types of Waspmote Plug & Sense! sensor devices and a Meshlium multiprotocol Internet gateway. The Waspmote Plug & Sense! nodes used in this project are modular and can monitor and measure a wide range of factors: up to seven initial parameters. •
Smart Agriculture: Temperature (x2)
•
Smart Environment: CO2, VOC
•
Ambient Control: Temperature,
Humidity, Luminosity (Luxes accuracy) •
Smart Cities: Microphone (dBA)
Each Waspmote Plug & Sense! node contains the appropriate sensors and electronics needed to control them, and are formatted from the factory to adapt to each specific use. The encapsulated nodes also contain: •
Battery
•
Communications module: 802.15.4
•
220V charger/adapter
Waspmote Plug & Sense! houses a battery in its enclosure to allow the system to measure and transmit data even without a connected power supply. The battery capacity is 6600mAh; this means that application autonomy can range from several days to several weeks without recharging the battery, depending on sampling frequency (time between measurements). The
Waspmote Plug & Sense! houses a battery in its enclosure to allow the system to measure and transmit data even without a connected power supply.
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SENSOR TECHNOLOGY
Waspmote Plug & Sense! nodes can operate under battery power or on the grid to continuously recharge the battery.
Meshlium: Gateway to the Cloud Meshlium is a multiprotocol gateway and can be configured with different communication protocols such as Wi-Fi, Ethernet, and 802.15.4. This enables the system to receive sensor data from the nodes, parse it, and store it in a local database.
Smart Factory Meshlium gateway communicates with the Cloud.
The use of 802.15.4 communication technology allows sensor data to be stored or read as it is measured, so that users can visualize data “live,” in real time. By introducing an IP address in a browser all the Smart Factory information can be visualized on the Meshlium Web interface.
Pre-configured Software: Data is Accessible Anywhere, Anytime Each Waspmote Plug & Sense! node is programmed and tested in Libelium laboratories so that, once in position, it can start monitoring when the “ON” switch is pushed.
Smart Factory Application Dashboard.
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Waspmote Plug & Sense! monitors its corresponding parameters at different intervals because not all processes have the same priority or critical level. After each measurement, data is transmitted to Meshlium using 802.15.4; other info such as battery level is sent, to provide robustness to the solution.
TECH REPORT
Using Microsoft Azure allows Polibol to start sending data immediately without the need to configure their own server system. From the outset, the sensor data is available for download and local analysis, or it can be transferred to another server. Once the data is synchronized with the Azure platform, it can be accessed from anywhere. Meshlium synchronizes with Microsoft Azure platform every 60 seconds thanks to a Meshlium plugin that allows transmission of a local database directly to Azure.
“For us, the main advantages of using Microsoft Azure are its plug and play installation, immediate data availability, and ubiquitous access.” Rafael Asin of Polibol
According to Rafael Asin of Polibol: “For us, the main advantages of using Microsoft Azure are its plug and play installation, immediate data availability, and ubiquitous access.”
Waspmote: Low Power and High Performance Waspmote sensor nodes offer four power modes—on, sleep, deep sleep and hibernation. In the hibernate mode, it consumes 0.7µA resulting in outstanding battery performance. The device can keep running for up to three years without recharging the battery. After each measurement, Waspmote sleeps. This sleep feature, together with the ultra low-power sensors integrated within the Waspmote platform, extends the lifetime of the solution and makes it easy to install and maintain. Some Waspmote nodes can remain in place for months and years.
“The autonomy of each Waspmote Plug & Sense! will vary depending on the sampling frequency. When the nodes are connected to the grid, the energy balance is positive. When there is no current, the nodes can continue working for hours and even for days,” said David Remón, a Libelium engineer. Whether producing modern machines, high-performance products, or their components, smart sensor and Cloud-based technology is available for industrial automation to help manufacturers achieve top line growth by increasing productivity and minimizing risk in manufacturing processes.
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SENSOR TECHNOLOGY
Bare Conductive CONNECTS Ordinary Surfaces to the Digital World Interview with Matt Johnson Bare Conductive
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COVER STORY “Painting a sensor” has a funny ring to it. While the rise of the 3D printer has made unusual manufacturing techniques more popular in the maker space, the ability to paint a device still seems like fantasy. However, conductive paints have been in existence for decades now, but they have not gained any traction in the industry. Until now. Bare Conductive, a London-based tech startup, has capitalized on the immense potential of conductive paints. The company’s Electric Paint offering allows users to paint a sensor onto virtually any surface—all the user needs to do is plug it in. This provides makers with an incredible opportunity to develop new forms of electronic devices and to turn ordinary objects into digital hubs. EEWeb spoke with Bare Conductive’s Matt Johnson about some of the exciting applications that have spawned from their conductive paint and how the maker community will inspire where the product will go next.
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SENSOR TECHNOLOGY
What was the motivation behind starting Bare Conductive? There were two forces that acted on us to create this company. On one side, I took a design course during my graduate studies, and one of the projects was to create something based on your own brief. We were all interested in wearable electronics, but at the time, a lot of wearables were extremely bulky. This prompted us to think about putting sensors and electronics in different forms and on different substrates to create a new space for wearable electronics. The other force at play was the maker community and the easy access to opensource hardware. This made it possible for our project to move forward very quickly; if we had this idea ten years ago, the project may not have gone as far as it has.
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What exactly are you creating at Bare Conductive and what was the process like in creating it? None of us are material scientists, which is important to know because we approached the material in an extremely naïve way. We essentially asked ourselves if we could paint or print an electrical infrastructure on different surfaces. Conductive paint and inks are not new— they have been around for over a hundred years—so we went through the process of inventing something that someone else had already invented. This turned out to be a very useful mechanism for us. Our conductive paint uses carbon as a conductor, and even from the beginning we understood enough to know that we needed some sort of conductive particulate in most conductive coatings as well as a binder to hold it together and other materials to give it specific types of performance. We really started in the most analog way possible; we looked at a range of conductive particulates and binders and started to prototype the actual material to get it to work the way
COVER STORY we needed it to work. We eventually got to a prototype that was around 70 percent of what we were looking for. At that point, we started getting enough outside interest from what we were doing, so we brought in a material scientist to help us understand how to make it a real material and in the context of real clients.
What are some of the coolest applications you have seen from customers that use your conductive paint? That initial jar of paint was really a platform as opposed to a product. The reason I say that is that we were really hoping that from the beginning we would spark a diversity of ideas around using the material. I certainly think that has been true. We have seen people that have taken the material to a very sophisticated place in terms of design. We have seen people make beautiful interactive books, which was interesting because they were proposing that a piece of paper was a conduit for more information. It looked beautiful, it was really nicely executed, and you had no idea that it wasn’t just a book unless you touched it or interacted with it.
Bare Conductive’s Touch Kit
On the other side, we had people that used the material for shielding. Since it is water-based and non-toxic, which makes it easy to use and compatible with a lot of other substrates. It can be used in lots of projects where other conductive coatings aren’t necessarily appropriate.
“We essentially asked ourselves if we could paint or print an electrical infrastructure on different surfaces.”
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SENSOR TECHNOLOGY
We have also had people that have hacked the materials themselves. They either suspended the material in baby oil because it wouldn’t dry out, or they added solidifying materials together and they made conductive Silly Putty out of it. For us, that is the most exciting thing to see. In fact, two months ago, we had someone who e-mailed us with photos of a CNC tattoo machine that tattooed a piece of leather with the paint to make a capacitive interface. Two years ago, I would have never guessed we would see things like this.
Are there other modifications or applications that are on the horizon for the Bare Conductive paint? If you don’t plug our paint into anything, it’s not very exciting until you attach an LED or battery and it lights up, or if you attach it to a Touch Board and it turns into a capacitive sensor. That is a very important thing to keep in mind because a lot of people still think we make simple paint—but if all we did was make paint, we would not be a very compelling proposition. The addition of the firmware on the hardware and also the software that the maker community helped develop is what makes the paint really compelling. For us, it’s about filling out that stack to create different materials that have different performances. Right now, the paint is water soluble, so it is not appropriate for all environments, so we are aware that people want a more robust version. If we were to make a
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more robust version, then we might need hardware that is slightly different as well—giving the customer a paint with higher performance is not entirely useful until I give you the piece of hardware as well that can help get you the most of it.
On your website, you have marketed the conductive paint as an educational tool as well. How has the reception been on that side? In a way, the educational aspect of the paint was somewhat unintentional. One of the things we feel most strongly about is to get the most value out of what we do, we have to engage the widest audience. What is really exciting is that people with a lot of technical experience can look at our product with great interest, while at the same time, a teacher or student can look at it and wonder how it works or how to use it. Having both of those brains from both of those spheres interested in the same problem means that the outputs are going to be even more incredible and interesting. We have spent a lot of time trying to make sure that technical people are taking our product seriously and also people that might have failed physics in school, but their interest in electronics and technology is still being engaged with our offerings. Because of this, teachers find it easy to repurpose what we do for the classroom.
Your website offers the paint in relatively small quantities, but if a larger company came to you with an order of a thousand units, is that something you are able to accommodate at the moment?
COVER STORY “We looked at a range of conductive particulates and binders and started to prototype the actual material to get it to work the way we needed it to work.” This is certainly something that we are interested in. We actually have a few industrial partners that have presented applications like that that have played around with our materials and came to us asking how much a large order would be. In one sense, we are very much a “maker” company, but in another sense, we are actually a chemical manufacturer. We are a real anomaly in that sense, because there are very few chemical manufacturers that can actually survive producing so little chemicals. That is an interesting way to look at our company; we don’t really make very much paint, and the way that the paint-making ecosystem is set up doesn’t support companies like ours.
Bare Conductive’s Glowing House Set
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Enter the
Rift
Photo by Sergey Galyonkin
The latest virtual reality offering from Oculus is the most impressive headset yet. By Rob Riemen EEWeb Contributor
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EEWEB FEATURE
Virtual Reality (VR) is a concept that has been very difficult to master, even with today’s technologies. With the current VR offerings, the consensus is that the VR headsets made customers nauseous; the screen did not refresh fast enough, the sensors were not accurate, and the field of view (FOV) was too small to give users a believable depiction of the virtual world. Instead, the slow movement of the screen as well as the small FOV conflicted with the user’s natural visual perception and induced the feeling of nausea. However, in recent years, the team at the groundbreaking VR company Oculus saw that sensor and video technology was continually improving and harnessed those enhancements. The result is a truly revolutionary piece of hardware: the Oculus Rift.
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SENSOR TECHNOLOGY
With the Development Kit 2 (DK2), the Oculus Rift has come from a screen with equipment held together by ducttape to a full-featured VR headset. Using a handful of sensors, a single microcontroller circuit, and carefully positioned screens, the Oculus Rift Development Kit 2 is the finest, lowcost VR headset available—and it is not even finished. The DK2 is now available for the developers that have been eager to start developing new and immersive virtual content. Oculus Rift Developer Version
“Using a handful of sensors, a single microcontroller circuit, and carefully positioned screens, the Oculus Rift Development Kit 2 is the finest, low-cost VR headset available—and it is still in the development stages.”
The two monitors that can stretch the field of view to normal observable ranges might be considered the key player in the performance of the Oculus Rift DK2, but in reality the sensors are the backbone. The Oculus Rift DK2 uses the Invensense MPU-6000 sensor, which contains a gyroscope and an accelerometer, as well as the Honeywell HMC5983
Photo by Ats Kurvet
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EEWEB FEATURE magnetometer. These interface with the STMicroelectronics 23F103C8 ARM Coretex-M3 microcontroller, which allows the Oculus Rift to output realistic movement to the two screens it contains. With both a gyroscope and an accelerometer, the Invensense MPU6000 does a lot of work in helping provide the best VR experience. A gyroscope is a device that uses angular momentum to determine orientation. The Oculus Rift uses the data from this device to help determine a precise position of the user’s head. It does this by utilizing a Micro-Electro-Mechanical System (MEMS) that detects rotation about the X-, Y-, and Z-axes. When the Oculus Rift is rotated, this tiny system uses the Coriolis effect to cause a vibration that is sensed by a capacitive pickoff. A capacitive pickoff device is used to determine the relative positions of two objects. In this case, the pickoff devices are two very small objects inside of the gyroscope MEMS. The signal produced by the capacitive pickoff is amplified, demodulated, and filtered to generate a voltage, which is actually proportional to the angular rate. This results in transmissions that are digitized into 16bit Analog-to-Digital Converters (ACDs), which then allow the microcontroller to analyze and use the signal. In the case of the Oculus Rift, when the user is wearing the unit and moves their head to look downwards, the gyroscope feels this effect and generates a signal that is transmitted to the microcontroller. The microcontroller then calculates a position based on this signal and allows
Oculus Rift Development Kit Positional Tracker
“The Oculus Rift uses the data from this device to help determine a precise position of the user’s head.”
Oculus Rift Developer Version Back view and Control Box
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SENSOR TECHNOLOGY
the screen to output a visual that would correspond with the movement of the user’s head downwards. This applies to all directional movements as well; if the user swings their head to look behind them, the gyroscope will read these movements and send the appropriate signals to the microcontroller to allow the screens to adjust. But, the gyroscope only takes care of orientation—the accelerometer determines how fast those movements are. An accelerometer is a device that measures the g-force of an object, which is more commonly referred to as proper acceleration. When a user makes a movement, the accelerometer in the Oculus Rift calculates the acceleration of that movement on all three of its axes. When the user causes an acceleration across a particular axis, the proof mass becomes displaced and capacitive sensors use differentials to detect the displacement.
The accelerometer gives the Oculus Rift the ability to accurately portray the actual speed and direction of the movements of the user. When a user moves their head downwards, in conjunction with the gyroscope, the accelerometer gives the microcontroller the ability to judge the exact direction and acceleration of the user’s head. When the system refreshes the screens, the screens can keep up with the user’s forward and downward head movement and not give the user a feeling of nausea. If the user swings their head violently behind them to try to catch an approaching enemy, the screens will refresh almost instantaneously with the signals produced from both the gyroscope and the accelerometer. The gyroscope and the accelerometer do comprise of a large portion of measurements needed to give the user an accurate simulation of movement in a virtual world, but the signals from these sensors can only contribute so much. There are plenty of errors that occur in
“The confluence of sensor technology and real-time screen refreshing provides the user a nausea-free experience while providing a feeling of total immersion that cannot be felt with monitors.”
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EEWEB FEATURE both of these sensors, mainly tilt error and yaw error. Tilt error is compensated by adding a complementary filter to monitor and correct the signals produced by the gyroscope and the accelerometer. However, yaw error is more accurately corrected by a magnetometer. The Honeywell HMC5983 magnetometer measures the vector sum of three separate fields. One field is the Earth’s magnetic field. The second field is the magnetic field that exists in the local coordinate space of the sensor. The third field is a mix between the two—a local field that exists in the global fixed frame. The Oculus Rift uses the data from the magnetometer and these fields to determine reference points. These reference points are then used to detect yaw drift. From here, magnetometer calibration takes over, using the reference points of the yaw drift to correct the error. This allows the screen to refresh smoothly and accurately.
The gyroscope, the accelerometer, and the magnetometer provide the workload that the screens need in order to keep up with the movements of the user. In addition to complex sensor calibration, the screens of the Rift must have very high refresh rates to compensate using the signals given from the sensor. The confluence of sensor technology and real-time screen refreshing provides the user a nauseafree experience while providing a feeling of total immersion that cannot be felt with monitors. The DK2 comes with the Rift headset, a positional tracking device, a built-in latency tester, and a comprehensive SDK, and is available now for from the Oculus website.
BIBLIOGRAPHY Invensense. MPU-6000 and MPU6050 Product Specification Revision 3.4 (2013): 25. InvenSense. InvenSense, 19 Aug. 2013. Web. 24 Feb. 2015. LaValle, Steven M., Anna Yershova, Max Katsev, and Michael Antonov. Head Tracking for the Oculus Rift (2015): n. pag. University of Illinois at Urbana-Champaign. University of Illinois. Web. 23 Feb. 2015.
Photo by Skydeas
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SENSOR TECHNOLOGY
Wobble Wonder
T
he Oculus Rift is known for providing an unprecedented virtual reality experience. The
two-screen monitors in the headset offer the user a full field of vision that is hard to differentiate from reality. While the Rift often tricks the user into feeling vertigo or triggers reflexes from oncoming objects, the true potential of the Rift’s user experience had not yet been tapped. This led engineer and interaction designer Sophi Kravitz to develop a new platform (literally) that will enable users to take virtual reality to a whole other level. The result is the WobbleWonder, a fullon virtual reality experience that pairs a virtual Segway with the Oculus Rift headset. The user stands on the Segway
Offers Immersive Experience for OCULUS Users
and—through software and sensor integration—allows the user to move through virtual landscapes by leaning forward. With the addition of fans on the Rift headset, the user actually feels the virtual reality they experience. The WobbleWonder has taken off in the months since its debut, having been exhibited at maker expos throughout New York City, with more demos to come. EEWeb recently spoke with Kravitz about the inspiration behind the WobbleWonder.
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EEWEB FEATURE What prompted you to develop the WobbleWonder? I participated in an event last year called ArtA-Hack, which brings engineers and artists together for collaboration. I was put in a group with three other artists, and we wanted to create something where you could move in the virtual world with your body. We knew the Oculus Rift would be a good starting point, so we ended up developing the fairly inexpensive Wobble Board that pairs with the Rift headset.
Can you describe the WobbleWonder experience? It feels pretty amazing because the Oculus Rift is so immersive, and it’s so easy to be in the virtual world the moment the user puts the Oculus Rift on. By using the game engine Unity 3D, you can feel the G-force in any terrain you encounter in the virtual world. We put the accelerometer right inside the Wobble Board, so the user feels themselves move forward in both the real world and virtual world.
For the demo of the WobbleWonder, we had Leap Motion attached. The Leap Motion feature does gestural analysis, so it can tell what your fingers are doing, meaning you can knock over things in the virtual world with your hands.
The demo had fans blowing on the gamer to simulate motion—were these attached to the accelerometer? I developed a fan driver shield to help trigger when the fans turn on. The accelerometer data had a range that I used to map the fans. The faster the user moved, the more wind the user would get.
What have you enjoyed the most about developing the wobble wonder? I very much enjoyed the collaboration aspect. The other three people on this project were all artists, so working with people who could make the work look really beautiful and take care of the user experience was really great. I also enjoyed working on something that wasn’t already available—I didn’t create this from a kit or tutorial, which was a fun challenge.
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