It’s March and I’m in Amsterdam doing some paperwork after a meeting. My phone rings. It’s Bart, my colleague, telling me about a cool project;
“It’s going to be all retro scifi cool“
Bart exclaims all excited on the other side of the phone.
He continues telling me they want to give a back to the future clock to the Mona Keijzer (State secretary for economics and climate). That’s in a few weeks, when she’s visiting Groningen. The goal is to show how Groningen is is far ahead in tech compared to the rest of the Netherlands.
“You can build one, right?”
I call Stef, we discuss the idea, decide to leave out the yellow digits and make the “destination time” green because it better matches the Topdutch/Groningen color scheme. In about 5 minutes the plan came to life. That’s how we roll in Groningen!
Time to build it!
Ok, Go! I have two weeks to design, build and make it look pretty.
First stop: google for parts. Bart already sent me some inspiration which showed someone using Adafruit displays. They’re pricey, but in stock at some dutch webshops so that’s going to be the route here. An arduino as microcontroller to drive the whole thing will suit just fine, and we need a real time clock with a back-up battery to store the time when the power is gone.
My delta printer could only print 2 frames at a time. Patience is a virtue they say. With all the parts printed we could move on to the fun part, actually building the thing which was next up, as the electronics were also due to arrive!
As soon as they did, I started soldering and tinkering. Soldering all the circuit boards to the displays was easy. The cool thing about these boards is they all have a driver chip which enables I2C communication. This means you can use just 4 wires (power, clock, data, ground) to drive a full board with the 33 individual segments (4*7 segments, 4 dots and middle “:”) And you can daisy-chain the whole thing with I2C, which saves a lot of wiring!
With the electronics all finished the hard work started.
One thing was to properly code the whole thing so the time and date would be displayed. With 3 pushbuttons the time could be set & stored. And I had to sort out our stupid daylight savings schedule. This means no user input would be required to change the time twice a year, which annoys me as hell as a UX designer. Oh, and I also had some cool ideas in my head to further accentuate the concept — more on that later on!
The other hard part was to finish the housing to make it look al retro & used — as if it had been in use for years, time travelling back and forth. The 3D printed front and sides were easy. But I decided early on the entire thing would have to be metal, to make it look and feel more authentic.
I used sheets of aluminium to cover the PLA plastics, all cut and drilled to size, and bent a larger part in a U-shape to create the backside, top and bottom. Effective, simple and sturdy. Problem: sheet aluminum doesn’t look old :(
So, grab a hammer, grab your soldering iron, use some sanding paper, whatever you need to make it look old and used. I even ended up using brown paint, painting over it and wiping it off again to create a more rusty look and feel. Reused some old PC casing screws to seal it, installed the batteries, print some labels, spray paint 3 layers of clear coat and done!
(all this took countless hours of course, but I had fun doing so, and fun is important, right? ;)
With push buttons on the back, a hidden power switch on the bottom for battery support and the arduino USB port sticking out at the side, we’re all done! Time for some more hours tinkering with a nice startup routine. I managed to bit-wise operate all display segments separately, so we could display text. And let’s animate the upper time from present time to the future to finish it all up! Stef created this great video which demonstrates it perfectly :)
Interested in building one yourself? Feel free to look at my crappy code and drop me a line if you have questions!