Is the restroom busy? Just ask Darth Vader and Luke Skywalker

In the Hopper Building, the lightsabers of Darth Vader and Luke Skywalker light up – in red and blue – when the restroom on the corridor is busy. This saves the computer scientists a lot of fruitless trips to locked restroom doors – and has quickly become the building’s main attraction.

[Translate to English:] De to figurer fortæller ikke blot, om toilettet er optaget. De samler også statistiske data om it-specialisternes toiletbesøg. Tidligere vågnede den ene idémand bag, Mads Møller Jensen, op til en rapport hver morgen kl. 06.00 med minimum og maksimum besøgstid fra dagen før. Fotos: Roar Paaske.

28 seconds. That’s how long it takes computer scientist Søren Brogaard Pedersen to stand up from his desk,walk down the hall on the second floor of the Hopper Building in Katrinebjerg, turn the corner and grasp the restroom door handle – only to discover that the restroom is busy. And an additional 28 seconds to make his way back to his office, bladder still unrelieved. This can add up to a not insignificant chunk of a working day spent on bootless journeys back and forth between your office and a locked restroom door. Compounded by the frustration that grows with each failed attempt.

The problem is obvious. The solution was not. Until February, when Søren Brogaard Pedersen and Mads Møller Jensen, both of whom work at the Interactive Spaces Lab at the Alexandra Institute, installed models of the the Star Wars characters Darth Vader and Luke Skywalker at the end of the hall.

Each figure is linked to one of the two restrooms on the hall: Darth Vader’s lightsaber glows red when his restroom is busy; likewise, Luke Skywalker’s glows blue. This means that the computer scientists with offices on the hall just have to poke their heads out of their offices to see if the restroom coast is clear.

The idea was hatched last December, Pedersen explains. His colleague Daniel Andersen came up with the additional twist of using Star Wars figures. A proposal which was received with enthusiasm by the rest of the lab, which brainstormed audio and lighting effects over lunch.

And once the parts they needed had arrived from China, it only took a couple of weeks to get the system up and running.

Both figures are connected to a circuit by wires attached to the walls leading to the restrooms. There are two battery holders in the hole in the doorframe where the restroom lock clicks in. When the metal lock shuts, they act as electrical conductors that power the lightsaber on the corresponding Star Wars figure.

Blinking Christmas trees and inflatable palm trees

But the idea isn’t really new – in fact, Mads invented what you might call a prototype five years back, when he was a PhD student sharing an office at AU with Tobias Sonne. And the two computer scientists were already frustrated over wasting time on unsuccessful trips to the restroom back then.

“So Tobias took action,” Mads remembers.

To make a long story short, the two PhD students erected two plastic Christmas trees at the end of the hall. One for each restroom. Both trees were connected to the restroom door locks. Green lights mean the restrooms were available; red, that they were busy.

Video: Tobias Sonne.

The Christmas tree restroom occupancy system blended in well with its Christmas ornament-festoned surroundings for the first month of its existence. But as December gave way to January, some of the older scientists began to feel that Christmas trees were no longer an appropriate decorating choice.

“So we tried out inflatable palm trees. But they kept going flat. We blew them up in the morning, and they were all limp by the afternoon. So that didn’t work out, and the evergreen Christmas trees came back,” Mads remembers.

The two Christmas trees still stand in the hall on the second floor of the Hopper Building, but they no longer twinkle now that the two inventors have moved on. Not a tenable situation, says Niels Olof Bouvin, an associate professor of computer science whose office is on the hall. “Let me put it like this: it’s serious enough that we are going to have to look at reimplementing the same functionality again,” he says.

At the same time, Tobias refined the system even further in the noble pursuit of sparing his colleagues from encounters with locked restroom doors. First he launched the website ‘Erderledigt’ (Is it available), which was also connected to the Christmas trees. The website provided live status updates on the restroom situation.

“So you didn’t even have to stick your head out the door,” Mads explains enthusiastically.

The icing on the cake was an app for Mac PCs. It represented the restroom door status by two vertical bars in your task bar which were either green or red – so all you had to do was glance at the top of your computer monitor.

At the apex of the development of the Christmas tree system, it was possible for employees to keep track of each other’s ‘restroom routines’ on Tobias Sonne’s website. Including statistics about average daily and weekly restroom visit times. Photo: Capture from the website, which is currently offline.

Is Big Brother keeping tabs on my restroom behavior?

But not everyone was equally keen on this elegant solution.

“Some people were concerned that someone might be monitoring their restroom habits, and that there was a possibility of being reprimanded for spending too much time in the restroom,” Mads explains.

A concern that was founded in the fact that the Christmas trees, in addition to telling users when the restroom coast was clear, also kept track of the length and frequency of their restroom visits.

“At that time, I received a report on the previous day’s restroom visits every morning at 6 am, including minimum and maximum durations of the restroom visits,” Mads remembers.

But he stresses that all of the data collected by both the Christmas trees and the Star Wars figures is anonymized, and that it’s not possible to see data for the individual restroom patrons.

Mads Møller Jensen demonstrates the programme that allows him and Søren Brogaard Pedersen to see restroom data on a large monitor. The green or red horizontal bar you see shows whether the restrooms are busy at two-minute intervals. During the interview, one restroom switches from red to green, which means that the coast is clear at the restroom guarded by Darth Vader.

“The most vehement critics are happy with it now,” he says.

According to Mads, it’s hard to resign your self to wasting all that time again once you’ve had the luxury of a system like his. So he and Søren started missing their Christmas trees soon after they moved to the hall upstairs in December of last year.

Ready for a university-wide roll-out

And here the new system has not only become indispensable faster than the Millenium Falcon. It has also become the building’s main attraction.

“No one comes to visit us without stopping by to see it,” Mads says.

Nonetheless, they haven’t yet been contacted by potential customers interested in implementing the concept in their own workplace.

But in the event that someone out there discovers a burning need for a similar device, Søren promises that it would be easy to roll out at the rest of the university.

Restroom data in the cloud

Mads doesn’t wake up to a report on his colleagues’ restroom visits any more, now that the Christmas trees have been replaced by visitors from space. But the two Star Wars characters collect just as much data – which they, perhaps appropriately, store in the ‘cloud’.

This simple graph show how many visitors Darth Vader’s and Luke Skywalker’s restrooms have had in particular time periods on particular dates.

In principle, Mads and Søren could run stats on how often, how long and when the restrooms are used.

“And we have actually joked about collating the data with the cafeteria’s menu,” Mads laughs.

But they don’t do anything with the data the system collects, they assure me. The system is simply a creative solution to a practical problem.

“We use technology as a tool, just like a carpenter might build something out of wood if he were going to solve this problem,” Mads says.

However, he has analysed the data sufficiently to produce one finding: Darth Vader’s restroom is the most popular. Possible because it’s closest to the hall.

On the other hand, Luke Skywalker delivers the best quote as you’re leaving the restroom:

“That’s okay. I’m never going back to this planet again.”

Søren Brogaard Pedersen (left) and Mads Møller Jensen together with the two figures. The restrooms are just around the corner.

Translated by Lenore Messick