iWall: An Illuminated Façade For Smart Lighting Research




The iWall is an interactive light installation that opens up new opportunities in Smart Lighting research, teaching, and development for researchers, students, artists and makers. It is installed high up along the entire façade of the Computer Science building at RWTH Aachen University, facing Halifaxstraße. The iWall installation opens to the public in December 2013.

The iWall is designed so users can interact with it outside the building using their mobile devices. The iWall is part of the Aixplorer project that is working on future approaches to city guide systems for tourists. Interactive façades are becoming commonplace in urban spaces, and future mobile city guide systems have an opportunity to use such displays to provide additional channels for information, art, and entertainment to tourists.

Why the iWall for Smart Lighting Research?

  • The iWall is a permanently visible statement about the importance and potential of photonics, right at a major research hub, visible to students, faculty, and visitors. Thousands of students from one of Germany's top-ranked computer science departments will be exposed to it on a daily basis, pointing them towards photonics and smart lighting as an exciting field to study and conduct research in.
  • The challenges of real-time content delivery, networking, synchronization, video display, power supply solutions, interactivity, sensor usage, and many other related photonics and smart lighting topics will be explored by students and researchers both while constructing the iWall and when writing new apps for it.

Respecting A Historic Building

The CS building is a protected historical building from the 1950s that used to host the "Pädagogische Hochschule", so special care was taken to find a solution for designing and installing the iWall so that it is completely invisible when looking at the façade during daytime. Only at nightfall, the illumination becomes noticeable. Even then, the iWall does not use direct LED point lights which would create a cheap, amusement-park look. Instead, its LEDs are mounted behind the permanent sun reflector panels that span the entire width of the building. The LEDs point downwards at an angle, thus indirectly illuminating the street-facing outside of the next sun reflector panel below with a soft glow. This creates larger, more subdued and elegant illumination effects and a spatially continuous impression.

Unique Format: 1920x10 — A FullHD Strip

The building constraints lead to an unusual format for the iWall: With a dot pitch of about 3 cm over the width of 60 meters, it features 1920 RGB LED pixels of vertical resolution, while the existing sun reflector structure only allows for 10 RGB LED pixels of vertical resolution at a dot pitch of about 20 cm, for a height of about 2 meters. This unique format — FullHD horizontal, but only 10 pixels vertical — challenges the designers of content and interactive applications for the display. At the same time, this elegant "illuminated band" perfectly fits the existing architecture, underlining its original design intentions.

A Smart Lighting Research Platform

The iWall will not just be a passive, automated display showing meaningless animations, however. Instead, we will create an API and programming interface so that researchers, students, artists and makers can turn the iWall into a tool for their own ideas and projects. The entire array of over 20,000 RGB LEDs can be individually controlled at framerates fast enough for completely smooth animated effects. A first workshop for these developers is included in this project. Here are just some sample ideas for directions that projects using the iWall could take:
  • Implement a side-scrolling game that people can play by connecting to the iWall online using their smartphone: Waving your phone up and down (or shouting, or...) controls your character while you try to evade the many obstacles coming towards you.
  • Have the stars of 80's video games parade the length of the CS building - Super Mario, PacMan gobbling pills,... (the original Lemmings game characters were only 10 pixels high!)
  • Provide a real-time collaborative drawing app that lets users doodle on the wall using their smartphone or tablet. Content slowly fades away after a while unless it's liked through social media.
  • Visualize the number of internet-connected devices currently in the building (or energy consumption, or illuminated offices, or...) in a scrolling graph view - complete with a history view of the past 24 hours
  • Use the elongated wall banner to display a local weather status and forecast based on live internet data
  • Artists can design reactive animations that detect sounds, or measure environmental parameters like light or humidity using local sensors we install, and that visualize the effects of changes in beautiful, serene patterns.
  • Play back video content at a full 30 fps — what kind of video material works on such a wide display?
  • Create a real-time, low-resolution "mirror" of the environment captured by a low-resolution image sensor; reflecting people walking by, cars passing, and other effects, in a stylized fashion, without invading privacy.
  • Show a low-resolution live view of people moving around the inside of the building, to make the building's façade "transparent".
  • Instead of the local environment, show a live street scene from a partner university somewhere in the world instead.
  • Provide a serene "signature" illumination effect that identifies the Computer Science building, similar to existing RWTH buildings like SuperC, Heizkraftwerk and others.
  • Of course the iWall can also display traditional text — over 50 detailed characters along its length. Application ideas: Provide real-time pointers for visitors at events ("ENTER HERE FOR GRADUATION CEREMONY ->"), for public transport ("<- BUS 33 TO DOWNTOWN ARRIVING IN 2 MIN"), for visitors ("DOMINO'S PIZZA DELIVERY ENTER HERE ->"), etc.

We are sure that students, artists and other makers, given the opportunity, will come up with countless even more creative ideas to breathe life into this unusual display.


Prof. Jan Borchers: Project idea

Dr. Thorsten Karrer: Senior Project Lead, driver development

René Bohne: Mechanics consulting

Jan Zimmermann: Mechanics, mountings

Sascha Schade: Electronics and software

Niklas Hauser: Electronics and software

Simon Jakubowski: Mobile app and web server development


  • Oct 14, 2013: While getting out of bed, Jan B. thinks a CS media façade would be cool. Initial discussions with Niklas in the lab.
  • Oct 17, 2013: Project kickoff with Mario, Jan Z., René, Jan B. at Dorkbot meeting. Tested mounting an LED strip to one of the sun reflectors, looks great at night.
  • ...
  • Dec 6, 2013: Tag Der Informatik takes place, organized by i10; iWall scheduled to be up and running.

Internal Project Pages - registered access only

Created by borchers. Last Modification: Friday 23 of February, 2018 16:14:57 by borchers.

Media Computing Group at RWTH Aachen