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568 Articles

Time And Tide Are One Thing

September 19, 2023 by 3 Comments

The rise of 3D printing has given us incredible things, from awesome tchotchkes to intricate chocolates to useful things like spare body parts. But none has been so vital to comedy as say, printing hats for sea urchins. That’s right, sea urchins like to cover up with various things and will happily don, say, a 3D printed hat if presented the opportunity.

So anyway, this is a tide clock that uses a printed sea urchin and various hats to tell the time until/between low and high tide. How? It uses the position of a given hat relative to a couple nOOds LED strands, one for high tide and another for low.

Inside the large bamboo enclosure is an TTGO that fetches cheaply-obtained tide information and displays it on the screen. The TTGO also controls a servo that moves the sea urchin around. As it moves, a magnet in the urchin’s head (?) attracts the next hat.

Before settling on the current design, [rabbitcreek] experimented with both a sand dollar and a sea urchin skeleton. All the files are available if you want to whip up your own.

This isn’t [rabbitcreek]’s first foray into tide clocks. Here’s a solar number that should last for years.

Clock Hack Gives DEC Rainbow A New Lease On Life

September 12, 2023 by 21 Comments

In retrocomputing circles, it’s often the case that the weirder and rarer the machine, the more likely it is to attract attention. And machines don’t get much weirder than the DEC Rainbow 100-B, sporting as it does both Z80 and 8088 microprocessors and usable as either a VT100 terminal or as a PC with either CP/M or MS-DOS. But hey — at least it got the plain beige box look right.

Weird or not, all computers have at least a few things in common, a fact which helped [Dr. Joshua Reichard] home in on the problem with a Rainbow that was dead on arrival. After a full recapping — a prudent move given the four decades since the machine was manufactured — the machine failed to show any signs of life. The usual low-hanging diagnostic fruit didn’t provide much help, as both the Z80 and 8088 CPUs seemed to be fine. It was then that [Joshua] decided to look at the heartbeat of the machine — the 24-ish MHz clock shared between the two processors — and found that it was flatlined.

Unwilling to wait for a replacement, [Joshua] cobbled together a temporary clock from an Arduino Uno and an Si5351 clock generator. He connected the output of the card to the main board, whipped up a little code to generate the right frequency, and the nearly departed machine sprang back to life. [Dr. Reichard] characterizes this as a “defibrillation” of the Rainbow, and while one hates to argue with a doctor — OK, that’s a lie; we push back on doctors all the time — we’d say the closer medical analogy is that of fitting a temporary pacemaker while waiting for a suitable donor for a transplant.

This is the second recent appearance of the Rainbow on these pages — [David] over at Usagi Electric has been working on the graphics on his Rainbow lately.

Turning Soviet Electronics Into A Nixie Tube Clock

August 27, 2023 by 17 Comments

Sometimes you find something that looks really cool but doesn’t work, but that’s an opportunity to give it a new life. That was the case when [Davis DeWitt] got his hands on a weird Soviet-era box with four original Nixie tubes inside. He tears the unit down, shows off the engineering that went into it and explains what it took to give the unit a new life as a clock.

Each digit is housed inside a pluggable unit. If a digit failed, a technician could simply swap it out.

A lot can happen over decades of neglect. That was clear when [Davis] discovered every single bolt had seized in place and had to be carefully drilled out. But Nixie tubes don’t really go bad, so he was hopeful that the process would pay off.

The unit is a modular display of some kind, clearly meant to plug into a larger assembly. Inside the unit, each digit is housed in its own modular plug with a single Nixie tube at the front, a small neon bulb for a decimal point, and a bunch of internal electronics. Bringing up the rear is a card edge connector.

Continues after the break…

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

August 6, 2023 by 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 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.

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These Fake Nixie Tubes Have A Bootup Screen

July 15, 2023 by 34 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.

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Timekeeping For Distributed Computers

July 13, 2023 by 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.