The accelerometer takes in data created by the movement of the phone. Essentially an accelerometer brakes down to a weight surrounded by springs. When the phone is moved the weight is displaced and the spring compensates for the displacement. The force exerted by the spring to bring the weight back to center is measured to provide input to the phone. The springs themselves carry a small electrical current and what is measured is the fluctuations in current caused by the compression of the spring.
The accelerometer provides an easy and familiar way of doing things for many applications. If you are using it in a game then it often largely mimics a steering wheel or other a tilted surface mimicking a force of gravity that we are constantly aware of. It can often do things more quickly than delving through a menu and can be used to bi pass security settings.
For example because you and the other person involved bump your phones together once you are running the application, there is no need to go through a pass code of any kind. Often it provides a way to do something more quickly and with a level of sensitivity that is harder to achieve with a button because you have a range of inputs instead of a constant on or off.
While the accelerometer can be used effectively for simple actions, it’s applications are somewhat limited. While there have been many games that use the accelerometer, use often doesn’t extend beyond being used as a controller. Most other applications are merely measuring the input in raw data of the device. In most practical applications it doesn’t make sense to use an accelerometer.
Using the accelerometer to navigate a web page for example wouldn’t make sense, and while there is some research in to using the accelerometer as a gestural interface, this is a steep learning curve and defeats the purpose of NUI. As a mechanism for controlling games such as the pre-downloaded app Need for Speed or Flyy, the accelerometer excels. But what about an app that isn’t pure time-wasting material?
Layar is an Augmented Reality browser that, by combining all of the mobile phone’s user interface capabilities - gesture, camera, and accelerometer - create a unique user experience with its multiple functionalities. Layar was created in 2009 in the Netherlends for both iPhone and Android operating systems, though in the Android Market it’s truly flourished as the first Augmented Reality browser available.
Layar uses a combination of GPS and the Accelerometer to determine your exact location. Then, depending on which “layer” you are viewing you have access to the same relevant information. At its most basic level, Layar returns information about local places of interest that users may find interesting: resturants, stores, and tourist attractions. This information is then displayed on the screen, using the smartphone’s camera as a “viewfinder” into this three dimensional map. Layar released a developer’s toolkit for creating layers for sifting through specific information. We’ll take a look at three Layers created for this app, all that access the accelerometer.
The technology functions by enhancing one’s current perception of reality. This is done by taking a live view of reality and outputing it to a screen presenting an enhanced view with added content to it in the form of text, adding sound, or other on screen information. This creates the possibility of greater interactivity and social networking in a real world environment. The difference between augmented reality and virtual reality is that virtual reality completely substitutes a completely simulated world.
YellowPages was created by the company of the same name, a free layer that can uses local listings to help people find places through their search feature. You can determine how large of a radius it pulls information from (up to 10km around you) and what you want to return specifically. It will then return related matches to your search and how close they are to your current location, using the accelerometer to determine which ones you’re facing.
Twitter by Anca 3D is a real-time layar designed to connect with other twitter users that have the gps location enabled on their tweets. Nearby users are determined by the location of their last GPS enabled-tweet, their avatars appearing in that location. From there you can see their last tweet and get access to a timestream of the user’s tweets, where you can follow the user.
Ever wonder what being Pac-Man would feel like? With the help of this layar it’s possible to do so. ARcade Beta puts you in the place of Pac-Man, gathering pellets and fruit as you move around town. This is one of the functions where the accelerometer really shines, placing ghosts and other objects in your path at various heights that tilting the phone (and moving in another direction) allows you to avoid.
Drawing on Maeda’s 10 laws of simplicity we can take another look at this app and see how well it functions. Layar’s interface is relatively simple, but navigation through the seemingly endless amount of layers that one can use is complex enough that user response has been that it is seen as confusing and aggravating. The learning curve on this app is steep.
In context, the complex learning curve is necessary because the goal of the app is an augmented reality. But the crucial part of this app is that it provides the user with continually updating information in a “three-dimensional” space, which Layar is slow and painfully difficult to achieve. The individual layers take awhile to load, and because of the multiple NUIs that make up the app’s functions, it drains the battery power very quickly.
In order for many of the applications to be of any use it you have to be in an area in which people have developed content for that area. If you live in a place like Peoria for example, you aren’t going to be able to do much besides play games and use an app like the yellowpage app that has the capitol to push a nationwide app.
In Designing Gestural Interfaces the physical task of using gestures is explained. Layar forces you to hold your phone outstretched from your body at eye level so that you can see and interact with the real world objects in front of you. Many of the applications are tour based to guide you through museums and cities.
So if you are using them you are probably not familiar with the area and thus you are going to rely heavily on the interface, meaning you will be wandering around with your phone outstretched in front of you looking like an idiot, spinning in circles in crowded areas. This can lead to tunnel vision and possibly a wonderfully memorable encounter with a chrome bumper and your ribcage.
Because it is simply one of the NUI systems used in this app, its role is a smaller part. The amount of time that it takes to combine the 3D landmarks inside the app make the view feel a bit sluggish or unnatural.
Is continually being experimented with in new ways. Many times the accelerometers in phones are being used to track the directional output from the device to experiment with an illusion of depth to screens. Other uses are using the phone as a musical instrument using the accelerometer to distort a note that you select on a grid on your phone.
Greater use of augmented reality and more intuitive gestural interaction. Changing the screen orientation in 3D so that you can read the text easily when the phone is on a flat surface.Often used as a remote. Another use that is in the works is similar to how a theremin uses movement to bend and shift pitch in song. Instead of using your hand, the position of the phone registers how much the pitch shifts.
In the end, the accelerometer as a NUI has only scratched the surface of its potential. Not because of a percieved lack of functionality, as Layar provides for us, but simply because current phones have a distinct lack of processing power needed to handle the incorporation needed in augmented reality apps. Are more possibilities available? Only time will tell.