Mobile Devices to Interact With Lighting Andrés Lucero

Nokia Research Center P.O. Box 1000, FI-33721 Tampere, Finland

andres.lucero@nokia.com

INTRODUCTION Advances in Light Emitting Diode (LED) technology provide a wide range of new opportunities for interaction with light. In this workshop paper, I will focus on the role mobile phones (and devices) have played in this lighting revolution. Mobile phones have been: 1) used as means to remotely control lighting, 2) fitted with LEDs to allow people to directly control lighting, and 3) enhanced with pico projectors, which provide new possibilities to cast light and shadows. Finally, I explore the idea of using space as cue to interact with lighting using mobile phones.

MOBILE DEVICES TO INTERACT WITH LIGHTING

Mobile Devices as Remote Controls The Light Emitting Diode (LED) has revolutionized the lighting industry. LEDs have provided a wide range of new lighting opportunities ranging from domestic [3] and retail use, to media façades [2]. In these examples, people interact with increasingly complex lighting systems indirectly using their mobile phones as remote controls.

Lucero et al. [3] proposed a Light Switch to control and modify atmospheric lighting in a bathroom that was fitted with 50 different light sources (Figure 1). Using an iPAQ with a small touch screen that communicates wirelessly to the main lighting system, users can access both frequent and sporadic use functions. Boring et al. [2] allow users to collaboratively (or competitively) interact with media façades from their mobile devices. Users aim at the façade and observe it in live video allowing them to point through the display, giving people the impression of touching the building (Figure 2). Two applications were implemented, a 15-piece puzzle game and a simple paint application, which were evaluated during the Ars Electronica Festival.

Mobile Devices That Glow LEDs have also been used as part of mobile devices to generate light auras [4] and modify people’s personal lightscape [6]. The use of LEDs on these devices has allowed people to interact with lighting directly and explore several possibilities for interaction.

Figure 1. A light switch interface to remotely control lighting.

Figure 2. Using live video to interact with a media façade.

Figure 3. Dynamic ambient lighting with LEDs on a mobile.

Qin et al. [4] introduced dynamic ambient lighting for mobile devices (Figure 3). Inspired by Philips’s Ambilight, the authors fit an array of 40 RGB LEDs to the back of an Android phone to display off-screen information. Two applications were implemented to show the possibilities of the prototype. The public transport locator uses illumination to help users find surrounding transport stations on a map. The call detector uses two proximity sensors to allow users to answer or reject an incoming call by placing their hand on the surrounding illuminated area (i.e., red or green half).

Copyright is held by the author/owner(s). DIS 2012, June 11-15, 2012, Newcastle, UK. Presented at the Workshop on Designing Interactive Lighting.

Figure 4. Acrylic cases with LEDs create personal lights.

Light Bodies [6] consist of mobile handheld lights that respond to audio and vibration input to investigate the relationships between spaces and personal lights. Translucent acrylic cases were fitted with 20 LEDs each (RGB, amber and white), a microphone and a vibration tab (Figure 4). The Light Bodies were deployed during three performance-like settings where people interacted with them in different ways (e.g., shaking, tapping, arranging, blowing or singing to the devices).

Mobile Phones That Project Light Pico projectors have increased in popularity in recent years. Especially in dark conditions, pico projectors can be used as flashlights and generate dramatic lighting and shadow effects that can be used for expressive interactions.

Several projects and prototypes have explored the potential (e.g., collaboration, storytelling) as well as exposed some of the limitations (e.g., brightness, battery consumption, size, privacy) of using pico projectors. PicoTales [5] is an example of pico projector use to support collaborative storytelling between collocated users. The prototype provides a simple sketching tool on mobile phones to allow groups of 2-3 users to create light characters that support the authors’ stories (Figure 5). A sensor-based approach is used to track the movement of each created character, thus allowing users to generate animations after an initial lightweight calibration procedure. The story is then combined and played back on a PC.

Figure 5. Pico projectors used to cast light onto objects.

SPACE AS A CUE TO INTERACT WITH LIGHT An additional way to interact with lighting using mobile phones could consist of using space as a cue to interact with light. Using devices enhanced with radio tracking technology [1], the relative positions of several devices (and light sources) can be tracked. No extra hardware is needed besides the enhanced phones, allowing people to freely move about a room or space to control lighting.

In practice, one person could use their device to act as a physical slider and control lighting parameters by moving in real space. Instead of having users looking down on their mobile device screens, users would directly observe how their movements in space influence the lighting in the environment. Different lighting parameters (i.e., color, intensity, saturation) could be triggered by other modalities that do not require visual attention (e.g., gestures or speech). Users could say certain parameters out loud or cycle through different options by shaking their device and receiving audio feedback about which option they are about to modify. Then users could activate and deactivate the controller by pressing anywhere on the touch screen to avoid unintentionally modifying lighting in the room. Several people could also collaboratively walk around the space and define lighting parameters in collaboration (or competition). Such an interaction style would allow people to fine-tune their lighting by going to the exact location where the light would be used, a truly mobile light switch that does not require their visual attention.

ACKNOWLEDGMENTS I would like to thank Sebastian Boring, Qian Qin, Susanne Seitinger, and Simon Robinson for providing pictures of the media façade, dynamic ambient lighting, Light Bodies, and PicoTales prototypes, respectively.

REFERENCES 1. Belloni, F., Kainulainen, A., Richter, A., Kalliola, K. and

Koivunen, V. Multi-Emitter Tracking System for Multi-Antenna Mobile Phones. In ICASSP 2009 Show and Tell.

2. Boring, S., Gehring, S., Wiethoff, A., Blöckner, A.M., Schöning, J. and Butz, A. Multi-user interaction on media facades through live video on mobile devices. In Proc. CHI '11. ACM (2011), New York, NY, USA, 2721-2724.

3. Lucero, A., Lashina, T. and Terken, J. Reducing Complexity of Interaction with Advanced Bathroom Lighting at Home. i-com 5 (1), Oldenbourg (2006), 34-40.

4. Qin, Q., Rohs, M. and Kratz, S. Dynamic ambient lighting for mobile devices. In Proc. UIST '11 Adjunct. ACM (2011), New York, NY, USA, 51-52.

5. Robinson, S., Jones, M., Vartiainen, E. and Marsden, G. PicoTales: collaborative authoring of animated stories using handheld projectors. In Proc. CSCW '12. ACM (2012), New York, NY, USA, 671-680.

6. Seitinger, S., Taub, D.M. and Taylor, A.S. Light bodies: exploring interactions with responsive lights. In Proc. TEI '10. ACM (2010), New York, NY, USA, 113-120.