the 3 needle ammeters that make up the face of the clock

IC Clock Uses Ammeters For A Unique Time-Telling Display

September 10, 2021 by Jim Heaney 24 Comments

It is a rite of passage for hackers to make a clock out of traditionally not-clock items. Whether it be blinking LEDs or servos to move the hands, we have all crafted our own ways of knowing when it currently is. [SIrawit] takes a new approach to this, by using ammeters to tell the time.

The clock is built using mostly CMOS ICs. A CD4060 generates the 1HZ clock signal, which is then passed to parallel counters to keep track of the hours, minutes, and seconds. [SIrawit] decided to keep the ammeters functioning as intended, rather than replacing the internals and just keeping the needle and face. To convert the digital signal to a varying current, he used a series of MOSFETs connected in parallel to the low side of the ammeters, with different sizes of current-limiting resistors. By sizing these resistors properly, precise movement of the needle could be achieved by turning on or off the MOSFETs. You can see the schematics and learn more about how this is achieved on the project’s GitHub page (at the time of writing, the most recent commits are in the ‘pcb’ branch).

In addition to the custom PCB that holds all the electronics, PCBs help make up the case as well. While the main body of the case is made out of a repurposed junction box, [SIrawit] had a PCB on an aluminum substrate manufactured for the front panel. While the board has no actual traces or electrical significance, this makes for a cheap and easy way to get a precisely cut piece of aluminum for your projects, with a sharp-looking white solder mask to boot.

We love to see cool and unique ways to tell the time, such as using Nixie Tubes to spell out the time in binary!

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Word clock in the style of the Christmas lights from Stranger Things. If you know, you know.

Stranger Things Message Board Passes The Time By Spelling It Out

September 5, 2021 by Kristina Panos 5 Comments

Will Netflix’s nostalgic hit Stranger Things be back for a fourth series anytime soon? We could pull out a Ouija board and ask the spirits, but we’d much rather ask closer to the source, i.e. a spirit in the upside down. And you know that the best way to do that is with LEDs — one for each letter of the alphabet so the spirit can spell out their messages.

Although contact with the Demogorgon’s world isn’t likely with [danjovic]’s open-source Stranger Things board, you are guaranteed to get the time spelled out for you every minute, as in, ‘it’s twenty-five (or six) to four’. And if you want to freak out your unwitting friends, you can covertly send messages to it from your phone.

There are two versions now — the original desktop version, and one that hangs on the wall and uses a high-quality photo print for the background. Both use an ESP-01 and an Arduino to help drive the 26 RGB LEDs, and use a DS2321 real-time clock for timing. We love the enameled wiring job on the wall-mount version, but the coolest part has to be dual language support for English and Brazilian Portuguese. You can check out demos of both after the break.

We’ve seen many a word clock around here, but this is probably one of the few that’s dripping with pop culture. If it’s stunning modernism you want, take a look at this painstakingly-constructed beauty.

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Binary Clock Lets The Nixies Glow

August 28, 2021 by Brian McEvoy 2 Comments

We’re not here to talk about another clock. Okay, we are, but the focus isn’t about whether or not it can tell time, it’s about taking a simple idea to an elegant conclusion. In all those ways, [Marcin Saj] produced a beautiful project. Most of the nixie clocks we see are base-ten, but this uses base-two for lots of warm glow from more than a dozen replaceable units.

There are three rows for hours, minutes, and seconds. The top and bottom rows are labeled with an “H” and “S” respectively displayed on IN-15B tubes, while the middle row shows an “M” from an IN-15A tube. The pluses and minuses light up on IN-12 models so you’ll need eighteen of them for the full light show, but you could skimp and use sixteen in twelve-hour mode since you don’t need to count to twenty-four. We won’t explain how to read time in binary, since you know, you’re here and all. The laser-cut acrylic is gorgeous with clear plastic next to those shiny nixies, but you have to recreate the files or buy the cut parts as we couldn’t find vector files amongst the code and schematics.

Silly rabbit, nixies aren’t just for clocks. You can roll your own, but they’re not child’s play.

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A Whole Lot Of Stepper Motors Make The Most Graceful 7-Segment Displays

August 11, 2021 by Mike Szczys 23 Comments

Over the years we’ve seen many takes on the 7-segment display. Among the most interesting are the mechanical versions of what is most often an LED-based item. This week’s offering is from [John Burd], who published a very odd video showing off the clock he made. But look beyond YouTuber antics and you’ll see the stepper motors he used to turn the segments are dripping with graceful beauty. (Video, embedded below.)

Okay if you want to hear [Charlie Sheen] say “Raspberry P-eye”, this is the video for you. [John] used Cameo to get the (former?) star to talk about what was used to build the clock. Like we said, the video is weird. Let’s embrace that right away and then never talk about it again.

The thing is, the build is such a good idea. [John] went with some stepper motors you can source relatively cheaply from Ali Express and the like. Typically they’re around a buck or two each and have a couple of wings for screw mounting brackets. This builds on the segment displays we’ve seen that use hobby servos by allowing you finer control of how the segments move. Sure, the 90° rotation isn’t all that much to work with, but it will be much smoother and you can get fancy with the kinematics you choose. The only place we see room for improvement is the alignment of the segments when they are turned “off” as you can see the center segment in the video thumbnail below is not quite level. Maybe a linkage mechanism would allow for a hing mechanism that aligns more accurately while hiding the servos themselves behind the mounting plate? It’s in your hands now!

In the demo video you’ll also find some interesting test rigs built to proof out the project. One just endurance tests the mechanism, but the other two envision water-actuated segments. One pumps a hollow, transparent segment with colored liquid. The other tried to use water droplets sprayed in the air to illuminate laser segments. Both are cool and we’d like to see more of the oddball approaches which remind us of the ferrofluid clock.

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Relay Logic Nixie Tube Clock Checks All The Boxes

August 9, 2021 by Ryan Flowers 5 Comments

There are a few words in the electrical engineering lexicon that will perk any hardware hacker’s ears. The first of course is “Nixie tubes” with their warm cold war era ambiance and nostalgia inducing aura. A close second is “relay logic”. Between their place in computing and telecom history and the way a symphony of click and clatter can make a geek’s heart go pitter patter, most of us just love a good relay hack. And then there’s the classic hacker project: A unique timepiece to adorn our lair and remind us when we’ve been working on our project just a little too long, if such a thing even exists.

With those things in mind, you can forgive us if we swooned ever so slightly when [Jon Stanley]’s Relay Logic Nixie Tube Clock came to us via the Tip Line. Adorned with its plethora of clicking relays and set aglow by four Nixie tubes, the Relay Logic Nixie Tube Clock checks all our boxes.

[Jon] started the build with relay modules that mimic CD4000 series CMOS logic chips. When the prototype stage was complete, the circuit was recreated on a new board that mounts all 55 Omron relays on the same PCB. The result? A glorious Nixie tube clock that will strike envy into even the purest hacker’s heart. Make sure to watch the video after the break!

[Jon] has graciously documented the entire build and even makes various relay logic boards available for purchase if you’d like to embark on your own relay logic exploits . His site overflows with unique clock projects as well, so you can be sure we’ll be checking those out.

If you feel inspired to build your own relay logic project, make sure you source genuine Omron relays, especially if your Relay Computer Masterpiece takes six years to build.

Thanks to [Daniel] for sending this our way. Got a cool project you’d like to share? Be sure to send it in via the Tip Line.

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Accurate Digital Clock Keeps Ticking With FPGA

August 8, 2021 by Chris Lott 12 Comments

Even the most punctual among us are content to synchronize their clocks to external time sources like navigation satellite constellations, network time servers, frequency-controlled AC mains, or signals broadcast by radio stations such as WWV, CHU, and DFC77 — but not [zaphod]. After building a couple of more traditional clocks over the years, he set his sights on making a completely isolated digital clock that doesn’t rely on external synchronization (well, except to initialize the time at first power-up).

The accuracy goal he set for himself was that of a Casio F-91W wristwatch, which is specified to maintain +/- 30 seconds per month (about 12 ppm). At the heart of the design is an oven-controlled crystal oscillator whose stability is in the single-digits parts-per-billion.

The counter chain that accumulates the time is implemented in an FPGA — admittedly overkill, but [zaphod] wanted to learn FPGA programming for this project as well. An ATmega328 drives the display and does other bookkeeping tasks. The whole design is partitioned into three PCBs which fit inside a custom 3D-printed case.

[zaphod] does a thorough job documenting his build, including the bugs and failures along the way. We like the honest summary he wrote at the project’s conclusion, noting things that could be improved or should have been done differently. Be sure to check out the GitHub repository, where all the source code and PCB design files are posted. How accurate is your wristwatch, if you even wear one anymore?

Wristwatch PCB Swaps Must Be In The Air

August 8, 2021 by Mike Szczys 19 Comments

Are we seeing more wristwatch PCB swapping projects because more people are working on them, or because we saw one and they’re on our mind? The world may never know, but when it comes to design constraints, there’s a pretty fun challenge here both in fitting your electronic wizardry inside the confines of an injection molded case, and in the power budget to make your creation run on a sippy straw of battery power.

Just this morning we came across [Joey Castillo’s] sensor-watch project. He chose the Casio F-91W as the donor wristwatch. It’s got that classic Casio look of a segment LCD display capable of displaying hours, minutes, and seconds, as well as day and date. But the added bonus is that we know these have decent water resistance while still providing three buttons for user input. Sure, it’s less buttons than the pink calculator watch we saw [Dave Darko] working on earlier in the week, but which would you trust in the pool?

Replacement PCB sized to use the same battery contact and CR2016 for power [via @josecastillo]

We see that [Joey] also chose to use the ATSAML22 microcontroller and sheds some light on why: it includes a built-in segment LCD controller! If you’re a peripheral geek like us, you can read about the SLCD controller on page 924 of the datasheet (PDF), it’s a whole datasheet onto itself.

The sensor part of the sensor-watch is a flex PCB breakout that allows you to swap in whatever sensor fits your needs. The first to be reflowed at [Joey’s] bench is a BME280 humidity sensor, which is most obviously useful for the included temperature measurements, but maybe it could also alarm at moisture ingress? [Joey] says you can swap in other parts as long as they’re in the QFN or LGA size range. We think an IMU is in order since there’s a lot of fun interaction there like the watch reacting to being positioned in front of your face, or to take tap-based inputs.

We think beginning with a donor watch is brilliant since pulling off a case, especially one that keeps water out, is 97% of the battle. But when your UI is unique to the watch world, sometimes you need to start from scratch like this wooden word clock wristwatch.