[gfish] was planning on attending Burning Man and wanted to make something unique (and useful) to wear. He decided on a hat/clock hybrid. Just slapping a clock on a hat would be too easy, though. [gfish] wanted his hat to change time zones both via manual switches or physical location.

On the front of the hat there are 2 hands, as most clocks have. Each one is attached to one of two concentric shafts that run to the back of the hat. Each hand is individually controlled by an RC vehicle servo. Those of you familiar with RC servos know that a servos’ max rotation is about 180 degrees and is certainly not enough for a full revolution required by the clock. To fix this, there is a 3:1 gear set that allows a 120 degree rotation of the servo to move the clock hand a full 360 degrees. With this method, each hand can’t move past 12 and instead has to quickly move counter-clockwise to get where it needs to be in order to again start its journey around the clock face.

Mounted inside the hat there is an Arduino that controls the clock, a GPS shield to determine location and an RTC to maintain accurate time. Mounted on the side of the hat is a control panel that contains an overall on/off switch as well as a rotary switch for selecting a specific timezone or for engaging GPS mode. The whole thing is powered by a 9 volt battery.

If you like unnecessarily complicated top hats, check out this WiFi enabled message displaying one.

[Bob’s] Pac-Man clock is sure to appeal to the retro geek inside of us all. With a tiny display for the time, it’s clear that this project is more about the art piece than it is about keeping the time. Pac-Man periodically opens and closes his mouth at random intervals. The EL wire adds a nice glowing touch as well.

The project runs off of a Teensy 2.0. It’s a small and inexpensive microcontroller that’s compatible with Arduino. The Teensy uses an external real-time clock module to keep accurate time. It also connects to a seven segment display board via Serial. This kept the wiring simple and made the display easy to mount. The last major component is the servo. It’s just a standard servo, mounted to a customized 3D printed mounting bracket. When the servo rotates in one direction the mouth opens, and visa versa. The frame is also outlined with blue EL wire, giving that classic Pac-Man look a little something extra.

The physical clock itself is made almost entirely from wood. [Bob] is clearly a skilled wood worker as evidenced in the build video below. The Pac-Man and ghosts are all cut on a scroll saw, although [Bob] mentions that he would have 3D printed them if his printer was large enough. Many of the components are hot glued together. The electronics are also hot glued in place. This is often a convenient mounting solution because it’s relatively strong but only semi-permanent.

[Bob] mentions that he can’t have the EL wire and the servo running at the same time. If he tries this, the Teensy ends up “running haywire” after a few minutes. He’s looking for suggestions, so if you have one be sure to leave a comment.

We’re surprised we haven’t seen this kind of clock before, or maybe we have, but forgot about it in the dark filing cabinets of our minds. The above picture of [danjhamer’s] Matrix Clock doesn’t quite do it justice, because this is a clock that doesn’t just tick away and idly update the minutes/hours.

Instead, a familiar Matrix-esque rain animation swoops in from above, exchanging old numbers for new. For the most part, the build is what you would expect: a 16×8 LED Matrix display driven by a TLC5920 LED driver, with an Arduino that uses a DS1307 RTC (real-time clock) with a coin cell battery to keep track of time when not powered through USB. [danjhamer] has also created a 3D-printed enclosure as well as added a piezo speaker to allow the clock to chime off customizable musical alarms.

You can find schematics and other details on his Hackaday.io project page, but first, swing down below the jump to see more of the clock’s simple but awesome animations.

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.

World Maker Faire was host to some incredible projects. Among the favorites was Nixie Rex [YouTube Link]. Nixie Rex is actually a Panaplex display, since it’s glow comes from 7 planer segments rather than 10 stacked wire digits. One thing that can’t be contested is the fact that Rex is BIG. Each digit is nearly 18 inches tall!

Nixie Rex was created by [Wayne Strattman]. Through his company Strattman Design, [Wayne] supplies lighting effects such as plasma globes and lightning tubes to the museums and corporations. Nixie Rex’s high voltage drive electronics were created by [Walker Chan], a PHD student at MIT. Believe it tor not the entire clock runs on an ATmega328P based Arduino. The digits are daisy chained from the arduino using common Ethernet cables and RJ45 connectors. A Sparkfun DS1307 based real-time clock module ensures the Arduino keeps accurate time.

[Wayne] and Rex were located in “The Dark Room” at Maker Faire, home to many LED and low light projects. The dim lighting certainly helped with the aesthetics, but it did make getting good photos of the clock difficult. Long time Hackaday tipster [Parker] graciously provided us with a size reference up above.

Click past the break to see a closeup of that awesome cathode glow, and a video of the Nixie Rex  in action.

Got to love that tube glow.

[Brett] just finished construction and long-term testing of this extremely accurate timepiece. It keeps such great time by periodically syncing with the atomic clock in Mainflingen, Germany.

The core of the project is an ATMega328 which uses the new DCF77 library for decoding the signal broadcast by an atomic clock. The libraries written by Udo Klein significantly increase the noise tolerance of the device reading the signal, but they will not work with any project that use a resonator rather than a crystal.

In the event of a complete signal loss from the atomic clock, the micro driving the clock also has a backup crystal that can keep the clock running to an accuracy of within 1 second per day. The clock can drive slave clocks as well, using pulses with various timings depending on what [Brett] needs them to do. The display is no slouch either: six seven-segment displays show the time and an LCD panel reads out data about the clock. It even has chimes for the hour and quarter hour, and is full of many other features to boot!

One of the most annoying things about timekeeping is daylight savings time corrections, and this clock handles that with a manual switch. This can truly take care of all of your timekeeping needs!

[Joakim] has built a clock that spells out the time in words. Wait a second – word clock, what is this, 2009? Word clocks are one of those projects that have become timeless. When we see a build that stands out, we make sure to write it up. [Joakim's] clock is special for a number of reasons. The time is spelled out in Norwegian, and since the clock is a birthday gift for [Daniel], [Joakim] added the his full name to the clock’s repertoire.

One of the hard parts of word clock design is controlling light spill. [Joakim] used a simple 3D printed frame to box each LED in. This keeps the spill under control and makes everything easier to read. The RGB LED’s [Joakim] used are also a bit different from the norm. Rather than the WS2812 Neopixel, [Joakim] used LPD8806 LED strips. On the controller side [Joakim] may have gone a bit overboard in his choice of an Arduino Yun, but he does put the ATmega328 and Embedded Linux machine to good use.

The real magic happens at boot. [Daniel's] name lights up in red, with various letters going green as each step completes. A green ‘D’ indicates an IP address was obtained from the router’s DHCP server. ‘N’ switches to green when four NTP servers have been contacted, and the Linux processor is reasonably sure it has the correct time. The last letter to change will be the ‘E’, which reports ambient light.

[Joakim] added a web interface to trigger his new features, such as a rainbow color palette, or the ability to show minutes by changing the color of the letters K,L,O,K. The final result is a slick package, which definitely brings a 2009 era design up to 2014 standards!

There are LED clocks, and then there are LED clocks that can blind you from 30 paces. [Stiggalicious's] LED ring clock is of the latter variety. 200 WS2812B/Neopixel RGB LEDs drive the ring clock to pupil searing levels. The clock runs on ATMega1284P, with timekeeping handled by an NXP PCF8563 real-time clock chip. Code is written in Arduino’s wiring language using Adafruit’s Neopixel library.

Building the clock with a single Printed Circuit Board (PCB) would be both expensive and wasteful. [Stiggalicious] cleverly designed his clock to be built with 8 copies of the same PCB. Each board makes up a 45° pie slice of the ring. All 8 PCBs have footprints for the CPU, clock chip, and other various discrete parts, but only the “master” section has these parts populated. 7 “slave” sections simply pass clock, data, power and ground through each LED. He used Seeedstudio’s board service to get 10 copies of his PCB made, just in case there were any mistakes.

[Stiggalicious] rolled the dice by buying exactly the 200 LEDs he needed. Either he got really lucky, or the WS2812 quality testing has improved, because only one LED had a dead blue LED.

If you’d like to find out more, [Stiggalicious] gives plenty of details in his Reddit thread. He doesn’t have a webpage setup for the clock but he’s uploaded his source code (pastebin link) and Altium schematic/PCB files (mega.nz link). We may be a bit biased, but hackaday.io would be a perfect spot for this or any other project!

Clocks have taken many forms of the years, starting with shadow clocks and sundials in Egypt around 3500 BC. Obviously, these could only tell the time while the sun was out. Water Clocks followed which could track time in the dark. Water Clocks are basically a bowl with a hole in the bottom. This bowl was set in a container filled with water. The water entered the bowl at a consistent rate and graduations on the inside of the bowl showed how much time had passed.

Mechanical clocks followed, as did quartz and the atomic clock. We have now entered a new era in time-telling, the Bamboo LED Clock. [Pascal] brings us this funky fresh chronometer all the way from Germany.

The front face is made from a bamboo pizza plate and gives the clock some modern minimalist pizzazz. A 1-meter long LED strip is attached to the circumference of the plate and contains 60 individually assignable RGB LED’s. An Arduino and Real Time Clock are responsible for the time keeping and coordination of the LED’s.

As you can see in the photo, 2 of the LED’s colors are used. The single red LED indicates the hour. The strip of blue LED’s show the minutes. If you’d like to build one of these [Pascal] has shared the Arduino code on his Instructables page.

[Keith] got his hands on a few grandfather clocks. Apparently the price tag is greatly reduced if you are able to get them second-hand. The mechanical timepieces require weekly winding, which is a good thing since you’ll also need to correct the time at least that often. But this drift got [Keith] thinking about improving the accuracy of these clocks. He figured out a high-tech way to adjust the timepiece while it’s ticking.

The first thing he needed was a source of super-accurate time. He could have used a temperature compensated RTC chip, but instead went the more traditional route of using the frequency of mains power as a reference. The next part of the puzzle is to figure out how to both monitor the grandfather clock and make small tweaks to its pendulum.

The answer is magnets. By adding a magnet to the bottom of the pendulum, and adjusting the proximity of a metal plate positioned below it, he can speed up or slow down the ticking. The addition of a hall effect sensor lets the Arduino measure the rate of each swing and calculate the accuracy compared to the high voltage frequency reference.