Micro Word Clock

A word clock – a clock that tells time with words, not dials or numbers – is one of those builds that’s on every Arduino neophyte’s ‘To Build’ list. It’s a bit more complex than blinking a LED, but an easily attainable goal that’s really only listening to a real time clock and turning a few LEDs on and off in the right pattern.

One of the biggest hurdles facing anyone building a word clock is the construction of the LED matrix; each LED or word needs to be in its own light-proof box. There is another option, and it’s something we’ve never seen before: you can just buy 8×8 LED matrices, so why not make a word clock out of that? That’s what [Daniel] did, and the finished project is just crying out to be made into a word watch.

[Daniel]’s word clock only uses eight discrete components: an ATMega328p, a DS1307 real time clock, some passives, and an 8×8 LED matrix. A transparency sheet with printed letters fits over the LED matrix forming the words, and the entire device isn’t much thicker than the LED matrix itself.

All the files to replicate this build can be found on [Daniel]’s webpage, with links to the Arduino code, the EAGLE board files, and link to buy the board on OSH Park.

Chicken-powered Pendulum

Every once in a while we get sent a link that’s so cute that we just have to post it. For instance: this video from [Ludic Science]. It’s a wind-up chicken toy that kicks a pendulum back and forth. No more, no less.

But before you start screaming “NOT A HACK!” in the comments below, think for a second about what’s going on here. The bird has a spring inside, and a toothed wheel that is jammed and released by the movement of the bird’s foot (an escapement mechanism). This makes the whole apparatus very similar to a real pendulum clock.

Heck, the chick toy itself is pretty cool. It’s nose-heavy, so that under normal conditions it would tip forward. But when it’s wound up, tipping forward triggers the escapement and makes it hop, tipping it backward in the process and resetting the trigger. The top-heavy chicken is an inverted pendulum!

And have a look, if you will indulge, at the very nice low-tech way he creates the pivot: a bent piece of wire, run through a short aluminum tube, held in place by a couple of beads. Surely other pivots are lower-friction, but the advantage of using a rod and sleeve like this is that the pendulum motion is constrained to a plane so that it never misses the chicken’s feet.

Our only regret is that he misses (by that much) the obvious reference to a “naked chick” at the end of the video.

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The ChronodeVFD Wristwatch

Not just another steampunk fashion statement, [Johngineer’s] ChronodeVFD wristwatch is as intricate as it is beautiful. Sure, we’ve seen our share of VFD builds (and if you want a crash course in vacuum fluorescent displays, check out Fran’s video from earlier this year) but we seldom see them as portable timepieces, much less ones this striking.

The ChronodeVFD uses a IVL2-7/5 display tube, which in addition to being small and low-current is also flat rather than rounded, and features a transparent backing. [Johngineer] made a custom board based around an AtMega88 and a Maxim DS3231 RTC (real time clock): the latter he admits is a bit expensive, but no one complains about left-overs that simplify your design.

The VFD runs off a Maxim MAX6920 12-bit shift register and is powered by a single alkaline AA battery. A rechargable NiMH would have been preferable, but the lower nominal voltage meant lower efficiency for his boost converters and less current for the VFD. [Johngineer] won’t get much more than 6-10 hours of life, but ultimately the ChronodeVFD is a costume piece not meant for daily wear. Swing by his blog for a number of high-res photos and further details on how he built the brass tubing “roll cage” enclosure as well as the mounts for the leather strap.

Dottie the Flip Dot Clock

What is it that we like so much about inefficient, noisy clocks made with inappropriate technology? Answer the question for yourself by watching the video (below) that [David Henshaw] sent us of Dottie, the flip-dot clock.

But besides the piece itself, we really like the progression in the build log, from “how am I going to do this?” to a boxed-up, finished project.

Another stunning aspect of this build is just how nice an acrylic case and a raft of cleverly written software can make a project look. You’d never guess from the front that the back-side was an (incredible) rat’s nest of breadboards and Ethernet wires. Those random switching patterns make you forget all the wiring.

And the servo-steered, solenoid-driven chimes are simply sweet. We’re sure that we’d love to hear them in real life.

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Joule Thief Steals Power for a Clock

A common project among electronics tinkerers is the joule thief, a self-oscillating circuit that can “steal” the remaining energy in a battery after the voltage has dropped so low that most devices would stop working. Typically the circuit powers an LED until almost all of the energy is extracted from the battery, but [Lionel Sears] has created a specialized joule theif that uses the “extra” energy to power a clock.

The circuit uses four coils instead of the usual two to extract energy from the battery. The circuit charges a large capacitor which provides the higher current pulses needed to drive the clock’s mechanism. It can power the clock from a single AA battery, and will run until the voltage on the battery is only 0.5 volts.

Normally the clock would stop running well before the voltage drops this low, despite the fact that there’s still a little chemical energy left in the batteries. The circuit can drive the clock for an extended time with a new battery, or could use old “dead” batteries to run the clock for a brief time while the final little bit of energy is drawn from them. If you’re so inclined, you could even use hot and cold water with a joule thief to run your clock! Thanks to [Steven] for the tip.

A Nixie Clock with Neon Bulb Logic

This is an oldie, but oh, man is this ever good. It’s a Nixie clock made without a microcontroller. In fact, there aren’t any logic chips in this circuit, either. As far as we can tell, the logic in this clock is made with resistors, diodes, caps, and neon tubes.

The design of this is covered in the creator’s webpage. This clock was inspired by a few circuits found in a 1967 book Electronic Counting Circuits by J.B. Dance. The theory of these circuits rely on the different voltages required to light a neon lamp (the striking voltage) versus the voltage required to stay lit (the maintaining voltage). If you’re exceptionally clever with some diodes and resistors, you can create a counting circuit with these lamps, and since it’s pretty easy to get the mains frequency, a neon logic clock starts looking like a relatively easy project.

This clock, like a lot of the author’s other work, is built dead bug style, and everything looks phenomenal. It looks like this clock is mounted to a plastic plate; a good thing, because something of this size would be very, very fragile.

Video below, thanks [jp] for sending this one in.

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Topsy Turvy Clock Tells Confusing Time

Looking for a new clock but hate the fact that all the numbers are always in the correct order? Look no further than [Andy]’s topsy turvy clock which correctly tells time despite the fact that the numbers on the face of the clock are in random positions.

At first glance, the clock looks fairly normal despite the mixed-up numerals. Upon closer inspection, the clock is much more than it appears to be. A battery backed real-time clock keeps track of time, and a microcontroller turns the hands of the clock to where they need to be. The clock uses optical sensors to make sure the hands are in the correct starting position when it is first powered on.

Check out the video below for a better illustration of what the clock looks like when in operation. The hour hand is always pointing at the correct hour, and the minute hand starts every five minutes at the number it would have started at on a normal clock, i.e. at 1:15 the hour hand will point at “one” and the minute hand will point at “three”.

We love this very interesting and unique take. It was inspired by a few other clocks, including a version of the infamous Vetinari “random tick” clock which will drive you crazy in a different way.