The primary purpose of a wristwatch is to tell the time, which pretty much any watch does perfectly fine. It’s in the aesthetics, as well as features other than time-telling, where a watchmaker can really make their product stand out from the rest. Watchmaker and electronic artist [Eric Min] focused on those two areas when he designed the Time Machine Mk.8, which combines exquisite design with simple, offline smartwatch functionality.
The heart of the watch is a Microchip ATSAMD21G18 low-power 32-bit microcontroller. [Eric] chose it for its high performance, ease of use and large number of integrated peripherals, a real-time clock being one of them. With the basic clock function thus taken care of, he then decided to add several useful sensors: a battery fuel gauge to keep an eye on the 40 mAh rechargeable lithium cell, a three-axis accelerometer to enable motion sensing and an environmental sensor to track temperature, humidity and pressure.
The various functions are operated using four pushbuttons along with a 16-step rotary encoder set in the middle. The overall design of the watch is inspired by Formula 1 steering wheels, as well as various sports cars and media franchises like Neon Genesis Evangelion and Akira. [Eric] considered a few different options for the display but eventually settled on two four-digit seven-segment LCDs, which fit nicely into the retro-futuristic aesthetic of the Mk.8. It’s so retro, in fact, that it almost makes [Eric]’s faux 1980s magazine ad look genuine.
All components neatly fit together on a dual-layer PCB, which is a true work of art in itself. From the lightning bolt on the front to the hidden Frank Sinatra lyrics, it definitely stands out from the crowd of ordinary LCD wristwatches. It’s also quite a step up from [Eric]’s previous watch design, the Time Machine Mk.IV.
Over the years we’ve seen several other examples of how a bare PCB, or even a stack of them, can become a beautiful wristwatch.
Nice design, but lack of case makes this watch rather fragile. It will be too easy to accidentally damage the display, not mentioning, what dirt and humidity can do to it. I didn’t look up the backside, but if it is not protected, the sweat would get into the circuitry.
Urgon– Yes, I was thinking the same. You’d have to be careful how you do it so it doesn’t come out all ‘globby’ or totally obscure the screen, but maybe you could dip/spray it with clear epoxy resin ? A brush wouldn’t work because then you’d have all the strokes.
There are quite a few options. I have somewhere a spray of polyurethane for conformal coating. A more retro option is to use rosin dissolved in alcohol. This not only will protect all solder joints but also will help if any additional soldering is needed.
The thing that worries me more is how delicate and unprotected is display itself. Any accidental bump will probably damage it. This watch wouldn’t last a week with me – I’m a bit accident-prone. The simple solution would be using a CNC to carve a case from polycarbonate. The machined surfaces could be then polished to get the transparency back. Also there were some quite successful attempts at clear 3D prints. Even a simple “bumper” around the PCB would protect it a bit, the way kid’s smartwatches have a raised case around the screen.
Yeah, the exposed glass of the LCD screens were one of my worries as well, but I’ve been wearing it almost every day for the past couple of weeks, and even after many dings and small drops, the LCDs are fine. There are lots of small microscratches but you can’t even see them unless you really try to under a bright light. The watch is a lot hardier than I thought it would be.
Hey, I made the watch. A lot of people have commented about this with my previous watches as well, but I’ve used it daily for the past several weeks, from sweaty hot weather to considerable rain. It worked perfectly without any issues, even in the rain as long as I had it covered up with a sleeve. The NATO single-piece strap covers up a good portion of the backside and gives the rear components more than enough clearance to not touch my skin.
The writer needs to look up “sleek” :-)
Yeah this is cool and I’m not putting it down, but sleek isn’t the aesthetic here. Not that that’s a bad thing, not everything needs to be sleek.
I’m kind of sick of sleek to be honest. I miss brick computers, brick phones, brick cars sometimes. They get me all bricked up
I also miss bricks :(
I’m glad when bricks miss me!
What is the LCD part number? The are adorable A.F.!
No idea on these one but I saw these that are really adorable too and exist in 2, 3 and 6 digits:
https://www.aliexpress.com/item/1005003745628043.html
https://www.hexpertsystems.com/LCD/
They’re pretty expensive, about 12 bucks a pop. Incredibly small and easy to use over I2C though!
Many tanks, guys!
Ideally should have used through-hole parts for the switches. SMD is wonderful for board design ingeneral, but things which get a lot of handling will always benefit from the mechanical strength of through hole soldering.
I don’t think that will ever be an issue. You are not smashing buttons with your fingers. Any other mechanical stress will probably damage the display first, and then break the PCB at strap slot.
Looking at those buttons and the ‘open’ design of the PCB (no case), I’m thinking: Wouldn’t it be possible to replace them with capacitors and thus make touch-buttons? A waveform on the capacitor will change when you put your finger on both contacts. I think it would be possible to measure.