Metro Light Cover Image Small.jpg

Metro Light


 Metro Light

How do you make the invisible, visible? How do you
interact with open data? Could you tap into the world of open
APIs to make something simple and meaningful?
We had three weeks to find answers to these questions.

Tangible Interaction Studio, Fall 2018.
Dhritiman Chatterjee.

Metro Light 1.jpg

What data is meaningful to you?

The thing with APIs is that there are infinite numbers of them and there is potential to make something cool with all of them. The trouble is to know what is meaningful to you. Therefore, we started the project by just exploring different open APIs like Twitter, Weather Data, Earthquake Data, Oslo Bikes, Ruter etc. For me, Ruter was the perfect match as it was fun, meaningful and exciting for me while being easy enough to use, so that, I could get the technical aspects of code out of the way and focus on the interaction aspects.

At that time I was living in Kringsja student village and it was winter. There is just one train out of there, every 15 minutes and if you ask anyone in Kringsja, missing the train is the biggest bummer. If you are even a minute late, you are waiting in the cold for 14 minutes for the next one. I wanted to make something that reduces the stress of catching the train in the morning.


Ruter API

Ruter has a wonderful API, which is very open and easy to use. I started exploring the timetable data and them moved on to the live departure data to track when is the next train leaving. I was interested in a very specific departure - Line 5 towards centre from Kringsja metro station. This made things simple and I was very quickly, with the help of our teacher - Nicholas Stevens, able to track how much time is left till the next departure.


Particle Photon

The micro-controller chip we were using is called Particle Photon and it is basically, a bit more powerful Arduino with wireless capabilities and a fully featured cloud platform. I wanted to make an object that you could just glance at, to get a very specific information. A glanceable display that is always in your home should be almost out of sight till you want to see it. Therefore, I started experimenting with a small form and gravitated towards light as an output.



I started with green foam to test the size and enclosure. Once I understood how to fit the chip, the lights and the wires, I started building a wooden case. From the very start I was aiming to make a product that can be manufactured and I aimed to make a prototype that looked and worked exactly like a final product. For the aesthetics, I chose bright white, as it was meant to be in your home and almost invisible and bright red, to make a visual connection with Ruter. I soldered the light array myself with 7 individually addressable “Neopixel” lights and then hooked it up to the Particle Photon chip.


That Specific Glow

I wanted the light to have a soft milky glow, which was proving difficult as there was just a few millimeters of gap between the acrylic surface and the LEDs. I made the case as compact as possible and I really did not want to make a thicker case. So, I experimented with diffusion of lights through various materials and finally, the combination shown underneath worked best.

Assembly 5.PNG

Time to Leave Home

The result was a small round softly glowing light that I named MetroLys of the Metro Light. I lived in building 34, which is exactly 8 minutes from the station by a normally paced walk. So, I subtracted 8 minutes from the time left for departure and I ended up with the final version of the metro light. It has four modes, depending on how long you would have to wait at the station if you started walking now.

Metro light glows white in its idle state to let you know that it is working. When it is almost time to leave home, it glows green. An amber glow means that it is as good a time as any to leave home if you want to make it without running and then a red flash which signifies that if you rush a bit, you could still make it. After that, it starts tracking the next train, and the cycle continues.

Metro light stays switched off between 10 pm to 7 am, so that you are not constantly blinded when trying to sleep. It also helps that you don’t need to unplug it and then plug it back again in the mornings.

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Testing the Metro Light

After the exhibition, I brought the light home and each of my flatmates (we are 8 people) used it for a week each and fell in love with it. If I ever produce it, I will always have customers in Kringsja. Therefore, I faked this advert as a way of getting new students to buy a 3 month ticket from Ruter.

The Metro Light does not work anymore as the API I was using is not supported anymore since the APIs moved to Entur.

This is just a mockup. SiO and Ruter logo used without permission.

This is just a mockup. SiO and Ruter logo used without permission.