clock hacks

912 Articles

The Tide Is High, And This Clock Lets You Know

September 9, 2018 by 7 Comments

In case you happen to have an ocean nearby, you’re probably familiar with its rising and falling tides. And if mudflat hiking is a thing in your area, you’re also aware of the importance of good timing and knowing when the water will be on its way back. Tide clocks will help you to be prepared, and they are a fun alternative to your usual clock projects. If you’re looking for a starting point, [rabbitcreek] put together an Arduino-based tide clock kit for educational purposes.

If you feel like you’re experiencing some déjà vu here, this indeed isn’t [rabbitcreek]’s first tide clock project. But unlike his prior stationary clock, he has now created a small and portable, coin-cell version to take with you out on the sea. And what shape would better fit than a 3D printed moon — unfortunately the current design doesn’t offer much waterproofing.

For the underlying tide calculation itself, [rabbitcreek] uses just like in his previous project [Luke Miller]’s location-based library for the ubiquitous DS1307 and DS3213 real-time clocks. Of course, if you also want to keep track of other events on your clock, why not set up calendar events for the next rising tide?

Transistor Logic Clock Gets Stacked Up

September 6, 2018 by 9 Comments

A couple years back we covered a very impressive transistor logic clock which was laid out so an observer could watch all of the counters doing their thing, complete with gratuitous blinkenlights. It had 777 transistors on 41 perfboards, and exactly zero crystals: the clock signal was extracted from the mains frequency of 50 Hz. It was obviously a labor of love and certainly looked impressive, but it wasn’t exactly the most practical timepiece we’d ever seen.

Creator [B Brett] recently wrote in to share news that the second version of his transistor logic clock has been completed, and we can confidently say it’s a triumph. He’s dropped the 41 perfboards in favor of 9 professionally fabricated PCBs, which this time around are stacked vertically to make it a bit more desktop friendly. The end goal of a transistor logic clock that you can take apart to study is the same, but this “MkII” as he calls it is a far more refined version of the concept.

In addition to using fewer boards, the new MkII design cuts the logic down to only 283 transistors. This is thanks in part to the fact that he allowed himself the luxury of including an oscillator this time. The clock uses a standard watch crystal at 32.768 KHz, the output of which is converted into a square wave through a Schmitt trigger. This is then fed into a divider higher up the stack which uses flip flops to produce 1Hz and 2Hz signals for use throughout the rest of the clock.

In addition to the original version of this project, we’ve also seen a beautiful single-board wall mounted version, and even a “dead bug” style one built from scraps.

Continue reading “Transistor Logic Clock Gets Stacked Up” →

A BCD Clock For Your Desk

September 1, 2018 by 8 Comments

We see so many clocks here at Hackaday, and among those we see our fair share of binary clocks. But to see one that at first sight looks as though it might be a commercial product when it is in fact a one-off project is something special. That’s just what [Tobi4sDE] has done though, with his desktop BCD binary LED clock.

The front panel is a black PCB on which sit the LEDs that form the binary display, and its back holds an ATMega328P microcontroller and DS3231 real-time clock. A smart desktop case is 3D-printed, and while the clock is USB-powered it features a CR2032 coin cell as a backup to hold the time while the USB is disconnected.

Unexpectedly he’s used a mini USB socket rather than the expected micro USB, but the rest of the clock is one we’d probably all have on our desks given the chance. We’d even go so far as to say we’d have this one as a kit if it were available.

Of course, regular readers will notice that this isn’t the only high-standard BCD timepiece you’ll have seen recently, though the other one was a wristwatch.

An Abstract Kind Of Clock: The Chinese Remainder Clock

August 27, 2018 by 15 Comments

Hackaday likes clocks, a lot. Speaking personally, from my desk I can count at least eight clocks, of which seven are working. There’s normal quartz movement analog clocks, fun automatic wristwatches, run-of-the-mill digital clocks, a calculator watch, and a very special and very broken Darth Vader digital clock/radio combo that will get fixed one day — most likely. Every clock is great, and one of life’s great struggles is to see how many you can amass before you die. The more unique the clock is, the better, and nothing (so far) tops [Antonella Perucca]’s Chinese Remainder Clock.

Continue reading “An Abstract Kind Of Clock: The Chinese Remainder Clock” →

An Arduino Watch Without A Clock

August 24, 2018 by 27 Comments

When you show up at a party wearing this bare PCB watch, there are effectively two possible reactions you might receive from the other people there. Either they are going to snicker at the nerd who’s wearing a blinking circuit board on their wrist in public, or they are going to marvel at the ridiculously low part count. We’ll give you one guess as to which reaction you’d likely get at any event Hackaday is involved in.

Designed and built by [Electronoobs], this extremely simple watch consists of a ATmega328P microcontroller, a dozen LEDs with their associated 200 Ω resistors, and a battery. There’s also a single push button on the front which is used to not only set the watch, but turn the LEDs on when you want to check the time. Short of dropping down to one LED and blinking out the time, it’s hard to imagine a timepiece with fewer components than this.

You’re probably wondering how [Electronoobs] pulled this off without an external clock source for the ATmega328P chip. The chip actually has an internal 8 MHz oscillator that can be used, but you need to flash the appropriate bootloader to it first. Accordingly, the backside of the PCB has both SPI and a UART solder pads for external bootloader and firmware programming.

As you might expect, there’s a downside to using the internal oscillator: it’s not very good. The ATmega328P spec sheet claims a factory calibrated accuracy of ±10%, and [Electronoobs] has found that equates to a clock drift of around 15 seconds per day. Not exactly great, but considering the battery only lasts for two days anyway, it doesn’t have much of an impact in this case.

Compared to other “analog” LED watches we’ve seen, the simplicity of this build is really quite remarkable. The closest competitor we’ve seen so far is this slick binary watch.

Continue reading “An Arduino Watch Without A Clock” →

What Will You Do If WWVB Goes Silent?

August 20, 2018 by 136 Comments

Buried on page 25 of the 2019 budget proposal for the National Institute of Standards and Technology (NIST), under the heading “Fundamental Measurement, Quantum Science, and Measurement Dissemination”, there’s a short entry that has caused plenty of debate and even a fair deal of anger among those in the amateur radio scene:

NIST will discontinue the dissemination of the U.S. time and frequency via the NIST radio stations in Hawaii and Ft. Collins, CO. These radio stations transmit signals that are used to synchronize consumer electronic products like wall clocks, clock radios, and wristwatches, and may be used in other applications like appliances, cameras, and irrigation controllers.

The NIST stations in Hawaii and Colorado are the home of WWV, WWVH, and WWVB. The oldest of these stations, WWV, has been broadcasting in some form or another since 1920; making it the longest continually operating radio station in the United States. Yet in order to save approximately $6.3 million, these time and frequency standard stations are potentially on the chopping block.

What does that mean for those who don’t live and breathe radio? The loss of WWV and WWVH is probably a non-event for anyone outside of the amateur radio world. In fact, most people probably don’t know they even exist. Today they’re primarily used as frequency standards for calibration purposes, but in recent years have been largely supplanted by low-cost oscillators.

But WWVB on the other hand is used by millions of Americans every day. By NIST’s own estimates, over 50 million timepieces of some form or another automatically synchronize their time using the digital signal that’s been broadcast since 1963. Therein lies the debate: many simply don’t believe that NIST is going to shut down a service that’s still actively being used by so many average Americans.

The problem lies with the ambiguity of the statement. That the older and largely obsolete stations will be shuttered is really no surprise, but because the NIST budget doesn’t specifically state whether or not the more modern WWVB is also included, there’s room for interpretation. Especially since WWVB and WWV are both broadcast from Ft. Collins, Colorado.

What say the good readers of Hackaday? Do you think NIST is going to take down the relatively popular WWVB? Are you still using devices that sync to WWVB, or have they all moved over to pulling their time down over the Internet? If WWVB does go off the air, are you prepared to setup your own pirate time station?

[Thanks to AG6QR for the tip.]

A Surprisingly Practical Numitron Watch

August 16, 2018 by 6 Comments

Regular Hackaday readers are surely familiar with Nixie tubes: the fantastically retro cold cathode display devices that hackers have worked into all manner of devices (especially timepieces) to give them an infusion of glowing faux nostalgia. But unfortunately, Nixie displays are fairly fragile and can be tricky to drive due to their high voltage requirements. For those who might want to work with something more forgiving, a possible alternative is the Numitron that uses incandescent filaments for each segment.

There hasn’t been a lot of prior-art that utilizes Numitrons, but that might be changing, given how fantastic this wristwatch created by [Dycus] looks. With a multi-day battery life, daylight readability, and relatively straightforward construction, the Filawatch is likely to end up being something of a reference design for future Numitron watches.

[Dycus] has gone through three revisions of the Filawatch so far, with probably at least one more on the way. The current version is powered by a ATmega328 microcontroller with dual 16-bit LED drivers to control the filaments in the KW-104S Numitron display modules. He’s also included an accelerometer to determine when the wearer is looking at the display, and even a light sensor to control the brightness of the display depending on the ambient light level.

If there’s a downside to Numitron displays, it’s their monstrous energy consumption. Just like in the incandescent light bulbs most of us have been ditching for LED, it takes a lot of juice to get that filament glowing. [Dycus] reports the display draws as much as 350 mA while on, but by lighting it up for only five seconds at a time it can be checked around 150 times before the watch needs to be recharged.

Its been a few years since we’ve seen a Numitron watch, and it’s interesting to see how the state of the art has advanced.

[via /r/electronics]