Cakeday Countdown Clock Is A Sweet Little Scroller

July 8, 2020 by Kristina Panos 2 Comments

If you want strangers to give you well wishes on your birthday out in the real world, you have call attention to the occasion by wearing a pointy hat or a button that says ‘today is my birthday, gimme presents’. But on your reddit cakeday, aka the day you joined, you’re automatically singled out with the addition of a slice of 8-bit cake next to your username. The great thing about your cakeday is that you’re almost guaranteed to get some karma for once, especially if you make something cakeday related like [ScottyD]’s cakeday countdown clock. But plenty of people forget what their cakeday is and miss out on the fun.

This countdown clock works like you might expect — every day that isn’t your cakeday, a message scrolls by with the number of days remaining until your next one. When the big day comes, the message becomes TODAY IS YOUR CAKE DAY. Both messages are bookended by cute little pixelated cake slices that we would apply liberally to the day-of message if we made one of these.

This simple but fun project shouldn’t put too big of a dent in your parts box, since it’s essentially an Arduino, a real-time clock module, and a 32×8 LED matrix to display the text. We love the uni-body design of the enclosure because it creates a shelf for the Arduino and gives easy access for gluing in the display from the rear. If for some reason you don’t reddit, then make one anyway and use it to count down to your IRL birthday or something. We’ve got the build video cut and plated for you to consume after the break.

We would understand if 2020 is supplying you with enough existential crises, but if not, consider building a clock that counts down the rest of your life expectancy.

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Measuring The Time Is A Breeze With This Air Flow Clock

June 25, 2020 by Dan Maloney 15 Comments

If you’ve ever had surgery, and you’re over a certain age, chances are good you’re familiar with the dreaded incentive spirometer. It’s a little plastic device with one or more columns, each of which has a plastic ball in it. The idea is to blow into the thing to float the balls, to ensure that your lungs stay in good shape and reduce the chance of pneumonia. This unique air-powered clock reminds us a little of that device, without all the pain.

Like a spirometer, [Nir Tasher]’s clock has three calibrated tubes, each big enough to hold a foam ball loosely. At the bottom of each tube is a blower whose motor is under PWM control. A laser rangefinder sits below each ball and measures its height; the measurement is used by a PID loop to control the speed of each fan and thus the height of each ball. The video below shows that the balls are actually pretty steady, making the clock easy to read. It doesn’t, however, reveal what the clock sounds like; we’re going to go out on a limb here and guess that it’s pretty noisy. Still, we think it’s a fantastic way to keep time, and unique in the extreme.

[Nir]’s Air Flow clock is an early entry in the 2020 Hackaday Prize, the greatest hardware design contest on Earth. Everyone should enter something, or at least check out the cool things people are coming up with. It’s still early in the process, but there are so many neat projects already. What are you waiting for?

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Dim Hallway Gets Lighting Upgrade

May 27, 2020 by Lewin Day 13 Comments

There’s nothing worse than a lightswitch that’s nowhere near where it should be, leaving you fumbling around in the dark. [supersquirrel72] had just this problem, and decided to put an Arduino to work instead.

Rather than using the original mains lighting that was poorly positioned and not enough to light the hall, instead 2 meters of white LED strip was chosen. The form factor is perfect for lighting a long, thin space – far better than running a series of seperate bulbs. The strip was rigged up to an Arduino Uno, that triggers the lights when movement is detected with a simple PIR motion sensor. After some feedback from the other occupants of the house, it was decided to tweak things further. An RTC was implemented to allow the Arduino to keep things dimmer after 9PM, so as to not wake others when making a trip to the kitchen for a midnight snack.

It’s a simple solution which brightens up the hallway nicely. We imagine this could just be the first step to a yet-more-integrated lighting solution in [supersquirrel72]’s house. Whether it’s IOT lights or something more festive, we can’t wait to see what’s next.

Passing The Time By Reading The Time

May 14, 2020 by Sven Gregori 4 Comments

Binary clocks are a great way to confuse your non-technical peers when they ask the time from you — not that knowing about the binary system would magically give you quick reading skills of one yourself. In that case, they’re quite a nice little puzzle, and even a good alternative to the quarantine clocks we’ve come across a lot recently, since you can simply choose not to bother trying to figure out the exact time. But with enough training, you’ll eventually get the hang of it, and you might be in need for a new temporal challenge. Well, time to level up then, and the Cryptic Wall Clock built by [tomatoskins] will definitely keep you busy with that.

Example of the clock showing 08:44:47 — Diagram of the clock showing 08:44:47

If you happen to be familiar with the Mengenlehreuhr in Berlin, this one here uses the same concept, but is built in a circular shape, giving it more of a natural clock look. And if you’re not familiar with the Mengenlehreuhr (a word so nice, we had to write it twice), the way [tomatoskins]’ clock works is to construct the time in 24-hour format by lighting up several sections in the five LED rings surrounding a center dot.

Starting from the innermost ring, each section of the rings represent intervals of 5h, 1h, 5m, 1m, and 2s, with 4, 4, 11, 4, and 29 sections per ring respectively. The center dot simply adds an additional second. The idea is to multiply each lit up section by the interval it represents, and add the time together that way. So if each ring has exactly one section lit up, the time is 06:06:02 without the dot, and 06:06:03 with the dot — but you will find some more elaborate examples in his detailed write-up.

This straightforward and yet delightfully unintuitive concept will definitely keep you scratching your head a bit, though you can always go weirder with the Roman numerals palm tree clock for example. But don’t worry, [tomatoskins] has also a more classic, nonetheless fascinating approach in his repertoire.

Servo-Powered 7-Segments Choreograph This Chronograph

April 22, 2020 by Kristina Panos 11 Comments

Good clocks are generally those that keep time well. But we think the mark of a great clock is one that can lure the observer into watching time pass. It doesn’t really matter how technical a timepiece is — watching sand shimmy through an hourglass has its merits, too. But just when we were sure that there was nothing new to be done in the realm of 7-segment clocks, [thediylife] said ‘hold my beer’ and produced this beauty.

A total of 28 servos are used to independently control four displays’ worth of 3D-printed segments. The servos pivot each segment back and forth 90° between two points: upward and flat-faced to display the time when called upon, and then down on its side to rest while its not needed.

Circuit-wise, the clock’s not all that complicated, though it certainly looks like a time-consuming build. The servos are controlled by an Arduino through a pair of 16-channel servo drivers, divided up by HH and MM segments. The Arduino fetches the time from a DS1302 RTC module and splits the result up into four-digit time. Code-wise, each digit gets its own array, which stores the active and inactive positions for each servo. Demo and full explanation of the build and code are waiting after the break.

When it comes to 7-segment displays, we say the more the merrier. Here’s a clock that uses pretty much all of them.

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Watch Your Life Tick Away With This Lifetime Countdown Clock

February 6, 2020 by Dan Maloney 26 Comments

Good news, everyone! Now you can have an ongoing existential crisis, every second of your ever-dwindling life with this personal life countdown timer.

Why would anyone want to be confronted by a count of the number of seconds left until you’ve made 80 trips around the sun? We can think of plenty of reasons not to, but creator [Jia Xun Chai] thought it would be somehow motivating to see the seconds tick irretrievably by while going about his life. Thus the idea for “Lifeclocc” came to be, with its ten seven-segment displays and Teensy to tally up and display the number of seconds left in a nominal 80-year life. A DS3231 RTC module keeps it on track between power-offs. It’s not clear what happens when you hit your 80th birthday; we assume it rolls over and starts counting up as you start playing in the bonus round. No word either on what happens should you croak with time left on the clock. Answer these questions and many more by building one yourself, or you can just wait for the Kickstarter.

It took [Jia Xun] three years to develop Lifeclocc, during which time his personal life clock decreased by 94,608,000 seconds. We will say that the finished product, with its matte-finish PCB, makes a handsome timepiece. Circuit sculptor [Mohit Bhoite] took a less-angsty stab at a similar clock, the cute appearance of which is no doubt intended to blunt the pain of impending doom.

Oceanography As Open As The Seas

January 17, 2020 by Kristina Panos 12 Comments

With Earth in the throes of climate change and no suitable Planet B lined up just yet, oceanography is as important now as it has ever been. And yet, the instruments relied upon for decades to test ocean conditions are holding steady within the range of expensive to prohibitively expensive. Like any other area of science, lowering the barrier of entry has almost no disadvantages — more players means more data, and that means more insight into the inner workings of the briny deep.

[Oceanography for Everyone] aims to change all that by showing the world just how easy it is to build an oceanographic testing suite that measures conductivity (aka salinity), temperature, and depth using common components. OpenCTD is designed primarily for use on the continental shelf, and has been successfully tested to a depth of 100 meters.

An Adalogger M0 and RTC Featherwing run the show from their waterproof booth in the center of the PVC tube. There’s a 14-bar pressure sensor for depth, a trio of DS18B20s for temperature averaging, and a commercial conductivity probe that gathers salinity data. These sensors are fed through a 3D-printed base plate and ultimately potted in stainless steel epoxy. The other end of the tube is sealed with a mechanical plug that seats and unseats with the whirl of a wingnut.

We particularly like the scratch-built magnetic slide switch that turns OpenCTD on and off without the need to open the cylinder. If you’d like to build one of these for yourself, take a deep dive into [Oceanography for Everyone]’s comprehensive guide — it covers the components, construction, and calibration in remarkable detail. The switch is explained starting on page 50. You can find out more about the work Oceanography for Everyone is doing at their site.

As far as cheap waterproof enclosures go, PVC is a great choice. It works well for underwater photography, too.