An Open Firmware For LILYGO’s E-ink Smart Watch

August 6, 2023 by Bryan Cockfield 21 Comments

The world’s first quartz wristwatches were miles ahead of electric and mechanical wristwatches by most standards of the time, their accuracy was unprecedented and the batteries typically lasted somewhere on the order of a year. Modern smart watches, at least in terms of battery life, have taken a step backwards — depending on use, some can require daily charging.

If you’re looking to bridge the gap between a day and a year, you might look into a smart watch with an e-ink display. One option is the ESP32-based LILYGO T-Wrist. Of course, it’s not a smart watch without some software to run on it, which is where qpaperOS comes in.

Developed by [qewer33], this open source firmware for the T-Wrist is designed to get the most out of the battery by updating only once per minute. With a 250 mAh battery, it should last about five days on a charge. Of course, with the power of the ESP32 comes a whole host of other features including GPS, a step counter, and a weather display, although since the firmware is still under development, some of these features have yet to be implemented.

With all of the code available, qpaperOS could make an excellent platform from which to build your own smart watch around. Or perhaps you could chip in and add some of the features on the whislity. The ESP32 is a capable and versatile chip, even capable of playing popular 8-bit video games, although we’re not sure this functionality would fit in a smart watch and preserve battery life at the same time.

Turning A Quartz Clock Module Into A Time Reference

July 21, 2023 by Lewin Day 11 Comments

If you’re looking for a 1-second time reference, you’d probably just grab a GPS module off the shelf and use the 1PPS output. As demonstrated by [InazumaDenki], though, an old quartz clock module can also do the job with just a little work.

The module was harvested from an old Seiko wall clock, and features the familiar 32.768 KHz crystal you’d expect. This frequency readily divides down by 2 multiple times until you get a useful 1 Hz output. The module, originally designed to run a clock movement, can be repurposed with some basic analog electronics to output a useful time reference. [InazumaDenki] explains various ways this can be done, before demonstrating his favored method by building the device and demonstrating it with a decade counter.

It has some benefits over a GPS time reference, such as running at a much lower voltage and needing no external signal inputs. However, it’s also not going to be quite as accurate. Whether that matters to you or not depends on your specific application. Video after the break.

Continue reading “Turning A Quartz Clock Module Into A Time Reference” →

These Fake Nixie Tubes Have A Bootup Screen

July 15, 2023 by Donald Papp 35 Comments

[IMSAI Guy] bought a fake Nixie clock, and luckily for all of us has filmed a very close look and demonstration. Using OLED displays as the fake Nixie elements might seem like cheating to some, the effect is really very well done.

Clock digits with bootup screens is something we didn’t know we liked until we saw it.

When it comes to Nixie elements, it’s hard to say which gets more attention and project time from hardware folks: original Nixie tube technology, or fake Nixie elements. Either way, their appeal is certainly undeniable.

Original Nixie tubes have shown up in modern remakes of alarm clocks, and modern semiconductors make satisfying a Nixie tube’s power requirements much easier with clever and compact Nixie drivers costing under $3 USD. This is also a good time to remind people that Nixie tubes don’t have to be digits. This audio spectrum visualizer, for example, uses IN-13 tubes which serve as elements of a bar graph.

Authentic Nixie elements require high voltages and are labor-intensive to manufacture to say the least, and as far as fake Nixie elements go, this one looks pretty good once it lights up. You can see it in action in the video, embedded below.

Continue reading “These Fake Nixie Tubes Have A Bootup Screen” →

Timekeeping For Distributed Computers

July 13, 2023 by Bryan Cockfield 14 Comments

Ask any programmer who has ever had to deal with timekeeping on a computer, and they’re likely to go on at length about how it can be a surprisingly difficult thing to keep track of. Time zones, leap years, leap seconds, various timekeeping standards, clock drift, and even relativity are all problems that can creep in to projects. Issues with timekeeping are exacerbated in distributed systems as well, adding another layer of complexity when we need to reliably determine the order that a series of actions occurred across a number of different computers with a high precision. One solution to this problem is the implementation of a vector clock.

When using other systems such as logical clocks to attempt to keep track of the order of events on different computers, a problem that may arise is that these systems don’t always track these changes with perfect reliability due to many issues such as varying temperature, race conditions, or clock skew. The vector clock instead tracks causal relationships between events. Each separate process maintains its own vector clock, represented by a list of integers. When one of these processes performs an event, it increments its own clock and sends it out to the rest of the system. By keeping track of this clock as it is updated by various processes across the computer the distributed system can be much more confident about the order in which events took place.

Of course, there are always downsides with elegant solutions like this. In the case of vector clocks the downside is largely increased overhead for keeping track of all of the sets of integers. But in systems where the ordering of processes is of the upmost importance, this is worth the trade-off to ensure reliability. And unless we hook all of our computers up to atomic clocks like they do for some computers at CERN we will have to take the increased overhead instead.

Clock Escapement Uses Rolling Balls

July 9, 2023 by Bryan Cockfield 15 Comments

The escapement mechanism has been widely used for centuries in mechanical clocks. It is the mechanism by which a clock controls the release of stored energy, allowing it to advance in small, precise intervals. Not all mechanical clocks contain escapements, but it is the most common method for performing this function, usually hidden away in the clock’s internals. To some clockmakers, this is a shame, as the escapement can be an elegant and mesmerizing piece of machinery, so [Brett] brought his rolling ball escapement to the exterior of this custom clock.

The clock functions as a kitchen timer, adjustable in 10-second increments and with several preset times available. The rolling ball takes about five seconds to traverse a slightly inclined, windy path near the base of the clock, and when it reaches one side, the clock inverts the path, and the ball rolls back to its starting place in another five seconds. The original designs for this type of escapement use a weight and string similar to a traditional escapement in a normal clock. However, [Brett] has replaced that with an Arduino-controlled stepper motor. A numerical display at the bottom of the clock and a sound module that plays an alert after the timer expires rounds out the build.

The creation of various types of escapements has fascinated clockmakers for centuries, and with modern technology such as 3D printers and microcontrollers, we get even more off-the-wall designs for this foundational piece of technology like [Brett]’s rolling ball escapement (which can also be seen at this Instructable) or even this traditional escapement that was built using all 3D-printed parts.

Continue reading “Clock Escapement Uses Rolling Balls” →

Clock Project Doesn’t Require A Decision

June 17, 2023 by Al Williams 12 Comments

You decide to build a clock. The first thing you have you determine if it is going to be digital or analog. Or is it? If you build [Ivanek240267]’s clock, you can have both.

The digital portion uses an OLED display. The analog portion contains two rings of smart LEDs. The WiFi configuration is always an issue in projects like this, and this clock also offers options. In addition, the Raspberry Pi Pico-based clock also sets itself via NTP.

You can, of course, compile the WiFi credentials into the code, and assuming you don’t plan on changing networks, that’s fine. But if you’re in a more dynamic situation, the clock can also read its configuration from a memory card.

The analog clock uses colors. The green LEDs represent quarter hours. The blue LEDs are for minutes, while the red ones are full hours. Of course, reading the OLED doesn’t require any special interpretation.

When debugging, the timing doesn’t drive the smart LEDs. That means if you need to work on that part of the code, you won’t be able to count on debugging support.

We’ve mentioned before that digital clocks are all analog, anyway. If you want to use fewer LEDs, you can get by with only five.

A wristwatch based on a red PCB with seven-segment LCD screens

The Time Machine Mk. 8 Is A Sleek Smartwatch With Retro Styling

June 11, 2023 by Robin Kearey 16 Comments

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.