Tag Archives: proximity sensor

Paper: LightRing: Always-Available 2D Input on Any Surface

In this modern world bristling with on-the-go-go-go mobile activity, the dream of an always-available pointing device has long been held as a sort of holy grail of ubiquitous computing.

Ubiquitous computing, as futurists use the term, refers to the once-farfetched vision where computing pervades everything, everywhere, in a sort of all-encompassing computational nirvana of socially-aware displays and sensors that can respond to our every whim and need.

From our shiny little phones.

To our dull beige desktop computers.

To the vast wall-spanning electronic whiteboards of a future largely yet to come.

How will we interact with all of these devices as we move about the daily routine of this rapidly approaching future? As we encounter computing in all its many forms, carried on our person as well as enmeshed in the digitally enhanced architecture of walls, desktops, and surfaces all around?

Enter LightRing, our early take on one possible future for ubiquitous interaction.

LightRing device on a supporting surface

By virtue of being a ring always worn on the finger, LightRing travels with us and is always present.

By virtue of some simple sensing and clever signal processing, LightRing can be supported in an extremely compact form-factor while providing a straightforward pointing modality for interacting with devices.

At present, we primarily consider LightRing as it would be configured to interact with a situated display, such as a desktop computer, or a presentation projected against a wall at some distance.

The user moves their index finger, angling left and right, or flexing up and down by bending at the knuckle. Simple stuff, I know.

But unlike a mouse, it’s not anchored to any particular computer.

It travels with you.

It’s a go-everywhere interaction modality.

Close-up of LightRing and hand angles inferred from sensors

Left: The degrees-of-freedom detected by the LightRing sensors. Right: Conceptual mapping of hand movement to the sensed degrees of freedom. LightRing then combines these to support 2D pointing at targets on a display, or other interactions.

LightRing can then sense these finger movements–using a one-dimensional gyroscope to capture the left-right movement, and an infrared sensor-emitter pair to capture the proximity of the flexing finger joint–to support a cursor-control mode that is similar to how you would hold and move a mouse on a desktop.

Except there’s no mouse at all.

And there needn’t even be a desktop, as you can see in the video embedded below.

LightRing just senses the movement of your finger.  You can make the pointing motions on a tabletop, sure, but you can just as easily do them on a wall. Or on your pocket. Or a handheld clipboard.

All the sensing is relative so LightRing always knows how to interpret your motions to control a 2D cursor on a display. Once the LightRing has been paired with a situated device, this lets you point at targets, even if the display itself is beyond your physical reach. You can sketch or handwrite characters with your finger–another scenario we have explored in depth on smartphones and even watches.

The trick to the LightRing is that it can automatically, and very naturally, calibrate itself to your finger’s range of motion if you just swirl your finger. From that circular motion LightRing can work backwards from the sensor values to how your finger is moving, assuming it is constrained to (roughly) a 2D plane. And that, combined with a button-press or finger touch on the ring itself, is enough to provide an effective input device.

The LightRing, as we have prototyped it now, is just one early step in the process. There’s a lot more we could do with this device, and many more practical problems that would need to be resolved to make it a useful adjunct to everyday devices–and to tap its full potential.

But my co-author Wolf Kienzle and I are working on it.

And hopefully, before too much longer now, we’ll have further updates on even more clever and fanciful stuff that we can do through this one tiny keyhole into this field of dreams, the verdant golden country of ubiquitous computing.


LightRing thumbnailKienzle, W., Hinckley, K., LightRing: Always-Available 2D Input on Any Surface. In the 27th ACM Symposium on User Interface Software and Technology (UIST 2014), Honolulu, Hawaii, Oct. 5-8, 2014, pp. 157-160. [PDF] [video.mp4 TBA] [Watch on YouTube]

Watch LightRing video on YouTube

Paper: Gradual Engagement between Digital Devices as a Function of Proximity: From Awareness to Progressive Reveal to Information Transfer

I collaborated on a nifty project with the fine folks from Saul Greenberg’s group at the University of Calgary exploring the emerging possibilities for devices to sense and respond to their digital ecology. When devices have fine-grained sensing of their spatial relationships to one another, as well as to the people in that space, it brings about new ways for users to interact with the resulting system of cooperating devices and displays.

This fine-grained sensing approach makes for an interesting contrast to what Nic Marquardt and I explored in GroupTogether, which intentionally took a more conservative approach towards the sensing infrastructure — with the idea in mind that sometimes, one can still do a lot with very little (sensing).

Taken together, the two papers nicely bracket some possibilities for the future of cross-device interactions and intelligent environments.

This work really underscores that we are still largely in the dark ages with regard to such possibilities for digital ecologies. As new sensors and sensing systems make this kind of rich awareness of the surround of devices and users possible, our devices, operating systems, and user experiences will grow to encompass the expanded horizons of these new possibilities as well.

The full citation and the link to our scientific paper are as follows:

Gradual Engagement with devices via proximity sensingMarquardt, N., Ballendat, T., Boring, S., Greenberg, S. and Hinckley, K., Gradual Engagement between Digital Devices as a Function of Proximity: From Awareness to Progressive Reveal to Information Transfer. In Proceedings of ACM Interactive Tabletops & Surfaces (ITS 2012). Boston, MA, USA, November 11-14. 10pp. [PDF] [video – MP4].

Watch the Gradual Engagement via Proximity video on YouTube

GroupTogether — Exploring the Future of a Society of Devices

My latest paper discussing the GroupTogether system just appeared at the 2012 ACM Symposium on User Interface Software & Technology in Cambridge, MA.

GroupTogether video available on YouTube

I’m excited about this work — it really looks hard at what some of the next steps in sensing systems might be, particularly when one starts considering how users can most effectively interact with one another in the context of the rapidly proliferating Society of Devices we are currently witnessing.

I think our paper on the GroupTogether system, in particular, does a really nice job of exploring this with strong theoretical foundations drawn from the sociological literature.

F-formations are small groups of people engaged in a joint activity.

F-formations are the various type of small groups that people form when engaged in a joint activity.

GroupTogether starts by considering the natural small-group behaviors adopted by people who come together to accomplish some joint activity.  These small groups can take a variety of distinctive forms, and are known collectively in the sociological literature as f-formations. Think of those distinctive circles of people that form spontaneously at parties: typically they are limited to a maximum of about 5 people, the orientation of the partipants clearly defines an area inside the group that is distinct from the rest of the environment outside the group, and there are fairly well established social protocols for people entering and leaving the group.

A small group of two users as sensed by GroupTogether's overhead Kinect depth-cameras

A small group of two users as sensed via GroupTogether’s overhead Kinect depth-cameras.

GroupTogether also senses the subtle orientation cues of how users handle and posture their tablet computers. These cues are known as micro-mobility, a communicative strategy that people often employ with physical paper documents, such as when a sales representative orients a document towards to to direct your attention and indicate that it is your turn to sign, for example.

Our system, then, is the first to put small-group f-formations, sensed via overhead Kinect depth-camera tracking, in play simultaneously with the micro-mobility of slate computers, sensed via embedded accelerometers and gyros.

The GroupTogether prototype sensing environment and set-up

GroupTogether uses f-formations to give meaning to the micro-mobility of slate computers. It understands which users have come together in a small group, and which users have not. So you can just tilt your tablet towards a couple of friends standing near you to share content, whereas another person who may be nearby but facing the other way — and thus clearly outside of the social circle of the small group — would not be privy to the transaction. Thus, the techniques lower the barriers to sharing information in small-group settings.

Check out the video to see what these techniques look like in action, as well as to see how the system also considers groupings of people close to situated displays such as electronic whiteboards.

The full text of our scientific paper on GroupTogether and the citation is also available.

My co-author Nic Marquardt was the first author and delivered the talk. Saul Greenberg of the University of Calgary also contributed many great insights to the paper.

Image credits: Nic Marquardt

Paper: Cross-Device Interaction via Micro-mobility and F-formations (“GroupTogether”)

GroupTogetherMarquardt, N., Hinckley, K., and Greenberg, S., Cross-Device Interaction via Micro-mobility and F-formations.  In ACM UIST 2012 Symposium on User Interface Software and Technology (UIST ’12). ACM, New York, NY, USA,  Cambridge, MA, Oct. 7-10, 2012, pp. (TBA). [PDF] [video – WMV]. Known as the GroupTogether system.

See also my post with some further perspective on the GroupTogether project.

Watch the GroupTogether video on YouTube

Lasting Impact Award for “Sensing Techniques for Mobile Interaction”

Last week I received a significant award for some of my early work in mobile sensing.

It was not that long ago really, that I would get strange glances from practical-minded people– those folks who would look at me with heads tilted downwards ever so slightly, eyebrows raised, and eyeballs askew– when I would mention how I was painting mobile devices with conductive epoxy and duct-taping accelerometers and infrared range-finders to them.

The dot-com bubble was still expanding, smartphones didn’t exist yet, and accelerometers were still far too expensive to reasonably consider on a device’s bill of materials. Many people still regarded the apex of handheld nirvana as the PalmPilot, although its luster was starting to fade.

And this Frankensteinian contraption of sensors, duct tape, and conductive epoxy was taking shape on my laboratory bench-top:

Sensing Pocket PC, circa 2000, with proximity range sensor, touch sensitivity, and tilt sensor

The Idea

I’d been dabbling in the area of sensor-enhanced mobile interaction for about a year, trying one idea here, another idea there, but the project had stubbornly refused to come together. For a long time I felt like it was basically a failure. But every so often myself and my colleagues who worked with me on the project– Jeff Pierce, Mike Sinclair, and Eric Horvitz– would come up with one new example, or another type of idea to try out, and slowly we populated a space of interesting new ways to use the sensors to make mobile devices smarter– or to be more honest about it, just a little bit less stupid– in how they responded to the physical environment, how the user was handling the device, or the orientation of the screen.

The latter led to the idea of using the accelerometer to automatically re-orient the display based on how the user was holding the device. The accelerometer gave us a constant signal of this-way-up, and at some point we realized it would make a great way to switch between portrait and landscape display formats without any need for buttons or menus, or indeed without even explicitly having to think about the interaction at all. The handheld, by being perceptive about it, could offload the decision from the user– hey, I need to look at this table in landscape— to the background of the interaction, so that the user could simply move the device to the desired orientation, and our sensors and our software would automatically optimize the display accordingly.

There were also some interesting subtleties to it. Just using the raw angle of the display, relative to gravity, was not that satisfactory. We built in some hysteresis so the display wouldn’t chatter back and forth between different orientations. We added special handling when you put the handheld down flat on a desk, or picked it back up, so that the screen wouldn’t accidentally flip to a different orientation because of this brief, incidental motion. We noticed that flipping the screen upside-down, which we initially thought wouldn’t be useful, was an effective way to quickly show the contents of the screen to someone seated across the table from you. And we also added some layers of logic in there so that other uses of the accelerometer could co-exist with automatic screen rotation.

Once we had this automatic screen rotation idea working well, I knew we had something. We worked furiously right up to the paper deadline, hammering out additional techniques, working out little kinks and details, figuring out how to convey the terrain we’d explored in the paper we were writing.

The reviewers all loved the paper, and it received a Best Paper Award at the conference. We had submitted it to the Association of Computing Machinery’s annual UIST Symposium– the UIST 2000 13th Annual Symposium on User Interface Software and Technology, held in San Diego, California– because we knew the UIST community was ideally suited to evaluate this research. The paper had a novel combination of sensors. It was a systems paper– that is, it did not just propose a one-off technique but rather a suite of techniques that all used the sensors in a variety of creative ways that complemented one another. And UIST is a rigorously peer-reviewed single-track conference. It’s not the largest conference in the field of Human-Computer Interaction by a long shot– for many years it averaged about two hundred attendees– but as my Ph.D. advisor Randy Pausch (now known for “The Last Lecture“) would often say, “UIST is only 200 people, but its the right 200 people.”

This is the video, recorded back in the year 2000, that accompanied the paper. I think it’s stood the test of time pretty well– or at least a lot better than the hair on top of my head :-).

Sensing Techniques for Mobile Interaction on YouTube

The Award

Fast forward ten years, and the vast majority of handhelds and slates being produced today include accelerometers and other micro-electromechanical wonders. The cost of these sensors has dropped to essentially nothing. Increasingly, they’re included as a co-processor right on the die with other modules of mobile microprocessors. The day will soon come where it will be all but impossible to purchase a device without sensors directly integrated into the microscopic Manhattan of its silicon gates.

And our mobile screens all automatically rotate, like it or not 🙂

So, it was with great pleasure last week that I attended the 2011 24th annual ACM UIST Symposium, and received a Lasting Impact Award, presented to me by Stanford professor Dr. Scott Klemmer, for the contributions of our UIST 2000 paper “Sensing Techniques for Mobile Interaction.”

The inscription on the award reads:

Awarded for its scientific exploration of mobile interaction, investigating new interaction techniques for handheld mobile devices supported by hardware sensors, and laying the groundwork for new research and industrial applications.

UIST 2011 Lasting Impact Award

In the Meantime…

I remember demonstrating my prototype on-stage with Bill Gates at a media event here in Redmond, Washington in 2001. Gates spoke about the importance of keeping spending– both in the public and private sectors– on R & D and he used my demo as an example of some up-and-coming research, but what I most strongly recall is lingering in the green room backstage with him and some other folks. It wasn’t the first time that I’d met Gates, but it was the first occasion where I chit-chatted with him a bit in a casual, unstructured context. I don’t remember what we talked about but I do remember his foot twitching, always in motion, driving the pedal of a vast invisible loom, weaving a sweeping landscape surmounted by the towering summits of his electronic dreams.

I remember my palms sweating, nervous about the demo, hoping that the sensors I’d duct-taped to my transmogrified Cassiopeia E-105 Pocket PC wouldn’t break off or drain the battery or go crazy with some unforseen nuance of the stage lighting (yes, infrared proximity sensors most definitely have stage fright).

And then less than a week later came the 9/11 attacks. Suddenly spiffy little sensors for mobile devices didn’t seem so important any more. Many product groups, including Windows Mobile at the time, got excited about my demonstration but then the realities of a thousand other crushing demands and priorities rained down on the fragile bubble of technological wonderland I’d been able to cobble together with my prototype. The years stretched by and sensors still hadn’t become mainstream like I had expected them to be.

Then some laptops started shipping with accelerometers to automatically park the hard-disk when you dropped the laptop. I remember seeing digital cameras that would sense the orientation you snapped a picture in, so that you could view it properly when you downloaded it. And when the iPhone shipped in 2007, one of the coolest features on it was the embedded accelerometer, which enabled automatic screen rotation and tilt-based games.

A View to the Future

It took about five years longer than I expected, but we have finally reached an age where clever uses of sensors– both for obvious things like games, as well as for subtle and not-so-obvious things like counting footfalls while you are walking around with the device– abound.

Any my take on all this?

We ain’t seen nothin’ yet.

Since my initial paper on sensing techniques for mobile interaction, every couple of years another idea has struck me. How about answering your phone, or cuing a voice-recognition mode, just by holding your phone to your ear? How about bumping devices together as a way to connect them? What of dual-screen devices that can sense the posture of the screens, and thereby support a breadth of automatically sensed functions? What about new types of motion gestures that combine multi-touch interaction with the physical gestures, or vibratory signals, afforded by these sensors?

And I’m sure there’s many more. My children will never know a world where their devices are not sensitive to motion and proximity, to orientation and elevation and all the headings of the compass.

The problem is, the future is not so obvious until you’ve struck upon the right idea, until you’ve found the one gold nugget in acres and acres of tailings from the mine of your technological ambitions.

A final word of advice: if your aim is to find these nuggets– whether in research or in creative endeavors– what you need to do is dig as fast as you possibly can. Burrow deeper. Dig side-tunnels where no-one has gone before. Risk collapse and explosion and yes, worst of all, complete failure and ignominious rejection of your diligently crafted masterpieces.

Above all else, fail faster.

Because sometimes those “failed” projects turn out to be the most rewarding of all.


This project would not have been possible without standing on the shoulders of many giants. Of course, there are my colleagues on the project– Jeff Pierce, who worked with me as a Microsoft Research Graduate Fellowship recipient at the time, and did most of the heavy lifting on the software infrastructure and contributed many of the ideas and nuances of the resulting techniques. Mike Sinclair, who first got me thinking about accelerometers and spent many, many hours helping me cobble together the sensing hardware. And Eric Horvitz, who helped to shape the broad strokes of the project and who was always an energetic sounding board for ideas.

With the passing of time that an award like this entails, one also reflects on how life has changed, and the people who are no longer there. I think of my advisor Randy Pausch, who in many ways has made my entire career possible, and his epic struggle with pancreatic cancer. I think of my first wife, Kerrie Exely, who died in 1997, and of her father, Bill, who also was claimed by cancer a couple of years ago.

Then there are the many scientists whose work I built upon in our exploration of sensing systems. Beverly Harrison’s explorations of embodied interactions. Albrecht Schmidt’s work on context sensing for mobile phones. Jun Rekimoto’s exploration of tilting user interfaces. Bill Buxton’s insights into background sensing. And many others cited in the original paper.

Award: Lasting Impact Award

Lasting Impact Award thumbnailLasting Impact Award, for Sensing Techniques for Mobile Interaction, UIST 2000. “Awarded for its scientific exploration of mobile interaction, investigating new interaction techniques for handheld mobile devices supported by hardware sensors, and laying the groundwork for new research and industrial applications.” Awarded to Ken Hinckley, Jeff Pierce, Mike Sinclair, and Eric Horvitz at the 24th ACM UIST October 2011 (Sponsored by the ACM, SIGCHI, and SIGGRAPH). October 18, 2011. Check out the original paper or watch the video appended below.

UIST 2011 Lasting Impact Award for "Sensing techniques for mobile interaction"

Sensing Techniques for Mobile Interaction on YouTube

Journal Article: Foreground and Background Interaction with Sensor-Enhanced Mobile Devices

Sensing for Mobile Interaction: Automatic Portrait-Landscape Rotation Hinckley, K., Pierce, J., Horvitz, E., and Sinclair, M. Foreground and Background Interaction with Sensor-Enhanced Mobile Devices. ACM Transactions on Computer-Human Interaction, Vol 12, No. 1 (Mar. 2005), pp. 31-52. [PDF] [video mpeg from UIST 2000 paper]

Sensing Techniques for Mobile Interaction on YouTube