The writeup starts at the beginning, going over the basic hardware requirements for a smart watch. This involves considering size, packaging and power draw, as well as the user interface. The build settles on an Arduino Pro Micro, as it uses the ATmega32U4 which eliminates secondary USB-to-serial chips, helping cut down on power consumption. A square IPS LCD display is used to display an analog-style watch face, and time is kept by a DS3231 real-time clock. A pair of small vibration sensors are used to wake the watch when the user moves their wrist to check the time.
While it doesn’t cover the final assembly into a watch-like form factor, it’s a handy guide on what it takes to build a working watch for those who are still getting their feet wet with hardware. Once you’ve got that down, it’s time to contemplate how you’ll build the sleek exterior. Naturally, a good maker has that covered, too.
Free-form circuitry built as open wire sculpture can produce beautiful pieces of electronics, but it does not always lend itself to situations in which it might be placed under physical stress. Thus the sight of [Mile]’s free-form wristwatch is something of a surprise, as a wristwatch cam be exposed to significant mechanical stress in its everyday use.
The electronic side of this watch is hardly unusual, the familiar ATmega328-AU low-power microcontroller drives a tiny OLED display. Mechanically though it is a different story, as the outline of a wristwatch shell is traced in copper wire with a very neat rendition of a Wrencher in its base, and a glass lens is installed over the screen to take the place of a watch glass. A strap completes the wristwatch, which can then be worn like any other. Power comes from a small 110 mAh lithium-polymer cell, which it is claimed gives between 6 and 7 hours of on time and over a month of standby with moderate use.
Unfortunately there does not seem to be much detail about the software in this project, but since ATmega328 clocks and watches are ten a penny we don’t think that’s a problem. The key feature is that free-form construction, and for that we like it a lot.
The Internet is a wild and wooly place where people can spout off about anything with impunity. If you sound like you know what you’re talking about and throw around a few bits of the appropriate jargon, chances are good that somebody out there will believe whatever you’re selling.
Case in point: those that purport that watches rated for 300-meter dives will leak if you wiggle them around too much in the shower. Seems preposterous, but rather than just dismiss the claim, [Kristopher Marciniak] chose to disprove it with a tiny wireless pressure sensor stuffed into a dive watch case. The idea occurred to him when his gaze fell across an ESP-01 module next to a watch on his bench. Figuring the two needed to get together, he ordered a BMP280 pressure sensor board, tiny enough itself to fit anywhere. Teamed up with a small LiPo pack, everything was stuffed into an Invicta dive watch case. A little code was added to log the temperature and pressure and transmit the results over WiFi, and [Kristopher] was off to torture test his setup.
The first interesting result is how exquisitely sensitive the sensor is, and how much a small change in temperature can affect the pressure inside the case. The watch took a simulated dive to 70 meters in a pressure vessel, which only increased the internal pressure marginally, and took a skin-flaying shower with a 2300-PSI (16 MPa) pressure washer, also with minimal impact. The video below shows the results, but the take-home message is that a dive watch that leaks in the shower isn’t much of a dive watch.
We are very familiar with retrocomputers, and if you want you too can build a computer that could have been made in the late ’70s on a breadboard. Just grab your CPU of choice, add some RAM, some ROM, a ton of jumper wires, and give it some way to talk to the outside world. The problem with the computers inspired by yesteryear is that they all, inexplicably, use through-hole parts. If only someone used the small QFP parts instead of the big chonkin’ PDIPs, we could have really small retrocomputers. That’s exactly what [NotArtyom] did, and he managed to come up with a wearable 6502 watch.
The system design for this 6502-based watch is fairly standard for what you would find in any other retrocomputer. There’s a PLCC 6502, 32k of SRAM, 16k of ROM, and a PLLC’d 6522 for a bit of IO. There are a few peripherals hanging off the 6522, and since this thing is a watch the most important is a real time clock. There’s also a Nokia LCD and a 20-pin Commodore keyboard connector.
Software-wise, most of the ROM is dedicated to G’Mon, a generic monitor that can view and modify memory. There’s also EhBasic, and a kernel to handle the RTC, keyboard, and display.
Whether or not this is a useful smartwatch isn’t the question; this is one of the first retrocomputer projects we’ve seen that lean into the non-PDIP versions of these classic chips. This is a bit surprising, because you can still buy these parts, PDIP or not, new from the usual vendors. If nothing else, it’s a demonstration of what can be done with modern IC packages.
Sporting a new wristwatch to school for the first time is a great moment in a kid’s life. When it’s a custom digital-analog watch made by your dad, it’s another thing altogether.
As [Chris O’Riley] relates, the watch he built for his son [Vlad] started out as a simple timer for daily toothbrushing, a chore to which any busy lad pays short shrift unless given the proper incentive. That morphed into an idea for a general purpose analog timepiece with LEDs taking the place of hands. [Chris] decided that five-minute resolution was enough for a nine-year-old, which greatly reduced the number of LEDs needed. An ATtiny841 tells a 28-channel I2C driver which LEDs to light up, and an RTC chip keeps [Vlad] on schedule. The beautiful PCB lives inside a CNC machined aluminum case; we actually commented to [Chris] that the acrylic prototype looked great by itself, but [Vlad] wanted metal. The watch has no external buttons; rather, the slightly flexible polycarbonate crystal bears against a PCB-mounted pushbutton to control functions.
So, a little hard to choose a topic, but we asked Simon to talk a bit about his recent Enigma watches. He has managed to put an electronic emulation of the Enigma cypher machine from World War II into both a wristwatch and, more recently, a pocket watch. They’re both gorgeous builds that required a raft of skills to complete. We’ll start there and see where the conversation takes us!
Please join us for this Hack Chat, where we’ll discuss:
Where the fascination with Enigma came from;
Tools, techniques, and shop setup;
Melding multiple, disparate skill sets; and
What sorts of new projects might we see soon?
You are, of course, encouraged to add your own questions to the discussion. You can do that by leaving a comment on the All Things Enigma Hack Chat and we’ll put that in the queue for the Hack Chat discussion.
Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.
It may only run for a brief time, and it’s too big for use in an actual wristwatch, but this 3D-printed tourbillon is a great demonstration of the lengths watchmakers will go to to keep mechanical timepieces accurate.
For those not familiar with tourbillons, [Kristina Panos] did a great overview of these mechanical marvels. Briefly, a tourbillon is a movement for a timepiece that aims to eliminate inaccuracy caused by gravity pulling on the mechanism unevenly. By spinning the entire escapement, the tourbillon averages out the effect of gravity and increases the movement’s accuracy. For [EB], the point of a 3D-printed tourbillon is mainly to demonstrate how they work, and to show off some pretty decent mechanical chops. Almost the entire mechanism is printed, with just a bearing being necessary to keep things moving; a pair of shafts can either be metal or fragments of filament. Even the mainspring is printed, which we always find to be a neat trick. And the video below shows it to be satisfyingly clicky.
[EB] has entered this tourbillon in the 3D Printed Gears, Pulleys, and Cams Contest that’s running now through February 19th. You’ve still got plenty of time to get your entries in. We can’t wait to see what everyone comes up with!