LED Pocket Watch

November 30, 2012 by Eric Evenchick 22 Comments

[Frank] wanted a classy way of telling the time, so he built up a LED Pocket Watch. The watch features 132 LEDs for displaying the time, two buttons to activate and change modes, a vibration motor, and a buzzer.

It’s controlled by a picoPower ATmega645P, which has enough pins to drive the array of LEDs, an internal real time clock, and low power consumption. The device is housed behind laser cut acrylic face, and sits in a 3D printed case.

To power the device, [Frank] used a rechargeable lithium coin cell battery. The charging circuitry is based on a MCP73831, which is an easy to integrate charge control IC. A USB connector is used to provide power to the board.

One of the bigger challenges of the design is driving the large array of LEDs. [Frank] uses Charlieplexing to group the LEDs and reduce the number of pins required. Another trick he used was offsetting the ISP header pins. This allows for programming the AVR without soldering a connector to the board.

[Frank]’s Instructables write-up is very detailed, and includes explanations of the schematic, PCB layout, software design, and case design. It’s a good read that details his design decisions.

After the break, watch [Frank]’s video overview of the project.

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Spare Parts Pulled Together Into A Nixie Clock

November 27, 2012 by Mike Szczys 6 Comments

We’d like to dig around in [Small Scale Research’s] parts bin. Apparently there’s good stuff in there because he managed to build this Nixie tube clock using mostly leftovers.

The chip driving the device is an ATtiny1634. We weren’t familiar with it so here’s a datasheet (pdf) if you’re curios as well. The microcontroller communicates with an old GPS module in order to keep perfect time. There is an external antenna for it which connects through the hole next to the red switch seen above. The high voltage driver is a repurposed backlight inverter which is fed 12V power from an old laptop supply.

The album linked above shows the build quite well and even includes full schematics. There are some fireworks when he encountered an issue with a pretty large cap shorting to a resistor leg. If this isn’t enough juicy detail for you there are a few more nuggets shared in the Reddit comments.

More CRT Fun With The Scope Clock

November 7, 2012 by Mike Szczys 13 Comments

That’s a sexy way to use parts from an old oscilloscope. [Aaron] took his inspiration from another project that was using CRTs from old oscilloscopes. Now he’s giving back with a site dedicated to sharing information about the Scope Clock. This project is along the same lines as the one we saw a few days ago.

The image above shows his first build in its new home in Hong Kong. The clock is housed in two clear acrylic containers, paired through a surprisingly beefy military grade connector. You can see the journey that it took to get to this polished finish by going to the Prototype tab at the top of the page linked above. One of the images shows some fast captures of the screen redraw. It lets you see the vectors which are being traced on the phosphor screen by the electron gun. This gives an image that we think is far more pleasing than the row scanning of a traditional CRT monitor.

Of course you don’t have a to start from scratch either. Here’s a clock project that just augments a functional CRT scope.

Nixie Clock That Doesn’t Skimp On The Number Of Tubes

November 2, 2012 by Mike Szczys 21 Comments

[Nina Blum] figures that if you’re going to the trouble of driving Nixie tubes you might as well use a lot of them. The details about this clock, which were sent directly to our tips line, lists a total of thirteen tubes used. There are six Russian IN-8 tubes (large digits), four Z573M tubes (small digits), but the colon tubes and the sine wave tube part numbers were not specified.

An ATmega8 controls the segments via a set of transistors. To operate the display [Nina] included a user interface made from five buttons and a four line character LCD. There is a video showing off the menu system that includes a way to set the time, date, and toggle the various illuminated bits. We’re waiting for permission to post that clip on our YouTube channel as [Nina] only included a Rapidshare link to the movie. Right now you’ll find more images after the break and we’ll embed the video if we get to okay.

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Scrapped DVD Player Turns Into A Full Featured Clock

October 30, 2012 by Mike Szczys 14 Comments

[Dmitry] really went the distance with this project. It started as a broken DVD player scrapped for parts, and turned into this clock with way too many features. That link is a pretty a dry technical collection of the work. You’ll definitely want to have a look at it, but we’d suggest first watching the demo video after the break which is initially much more exciting.

The donor DVD hardware included a Vacuum Fluorescent display which is the nugget which [Dmitry] was after. But that board came along with some other nice things, like an integrated IR receiver. He also chose to use the PSU from the device. An Arduino is used to drive the clock. We’re not sure where he found it, but the video shows the service manual for the DVD player which must have a been a real help in interfacing with the display. The white dome on the right is a PIR motion sensor. It brings the device out of sleep mode when someone is in the room.

The case is laser-cut and started as cardboard to ensure everything fit as designed. The enclosure makes it a showpiece, but the features of displaying day, date, time, and temperature make it functional as well. Since the VFD is alpha-numeric we think this could even see future upgrades to be used as a new-mail/tweet/IM alert as well.

QR Clock Is Unreadable By Humans And Computers Alike

October 29, 2012 by Brian Benchoff 44 Comments

The clock is a perfect technology. For just a few dollars, you can buy a digital wristwatch and chronometer able to keep extremely accurate time for years without winding a spring or replacing a battery. Anything ‘improvement’ on the design of a clock only makes it harder to read, a feature exploited by the very 1337 binary clocks we see from time to time. [Ch00f] decided it was time to give way to the march of progress and build a completely unreadable clock. He came up with a QR code clock that is unreadable by humans and cellphones alike.

The hardware is built around nine 8×8 LED matrix panels resulting in a 24 x 24 pixel display, perfect for displaying a 21 pixel square QR code. The LED drivers are a standard multiplexed affair, but this project really shines in the firmware department.

The microcontroller [Ch00f] used – an ATMega328 – is far too small to store the 1440 QR codes for every minute of the day. No, this project would have to dynamically generate QR codes on the fly, not exactly an easy problem.

After looking over the official QR code standard, [Ch00f] wrote a rather large program that turns alphanumeric sequences into QR code. This runs on the microcontroller every minute, generating a new QR code for every minute of the day.

It’s nigh impossible for a human to read a QR code, but [Ch00f] figured he could make his project even less useful. By multiplexing the LEDs at a very low duty cycle [Ch00f] made it impossible for a camera to capture the entire QR code, even though the pattern of pixels is still visible to the human eye. A fabulously useless build that really steps up the game for unreadable clocks.

Video after the break.

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A TTL Timer Project Of Yore

October 22, 2012 by Mike Szczys 6 Comments

[Viktor] just pulled out another one of his decades-old projects. This time around it’s a timer he built using 7400 logic chips. It was a great way for him to learn about electronics, and ended up serving as his alarm clock every morning.

Two pieces of copper clad board were cut to the same size. One of them was etched to act as the circuit board. The other was outfitted as a face plate. The same type of transfer sheets used to mask the traces of the circuit were also used to apply labels to the face plate. It was then coated with acrylic spray to protect it and stave off corrosion. The clock keeps time based on a half-wave rectified signal. The source is from a transformer which steps mains voltage down to a safe level for the 7805 regulator that supplies the clock’s power bus.

We’re glad [Viktor] has been showing off these old projects. We’ve also enjoyed seeing a TV sleep timer he built. If you’ve got something neat for yester-year why not dust it off, post the details, and send us a tip about it?