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.

Continue reading “QR Clock Is Unreadable By Humans And Computers Alike” →

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?

Automate Your Tea Time

October 22, 2012 by Mike Szczys 14 Comments

There are a couple of things that go into a great cup of tea. One is to have the water at the correct temperature, the other is to steep for just the right amount of time. This offering solves the latter by extracting the tea bag after a carefully timed steep.

It’s hard to imagine how this could be more simple. The timing mechanism is a cheap egg timer which has been modified to include a paperclip which moves with the minute hand. When the timer hits zero that paper clip contacts a stationary electrode, which powers the motor. That motor is the laser sled from a dead CD-ROM drive. Since these usually die because of the lens (not the mechanism) this is a great re-use of the internals. The sled zips to one side until it hits a limiting switch which kills the power. At the same time, this motion uses the wooden lever to extract the tea bag. All of this is explained in the clip after the jump.

Since the egg timer already has its own bell, you’ll even be alerted that it’s tea time!

Continue reading “Automate Your Tea Time” →

Wiring Up A Lot Of LED Segment Displays

September 21, 2012 by Mike Szczys 16 Comments

One look at this display and you know there’s a whole lot of pins that need to be wired up. Now look at what those display modules are mounted on. That’s right, [Kemley] is using point-to-point soldering to rig up this big display. It sports four sixteen segment modules on top for alpha-numeric information, and eight large seven segment modules for displaying numbers only.

We’re not certain as to how the electronics are arranged. When talking about the 16-segment modules he mentions that all four are in parallel with NPN transistors to switch the common anode of each. That’s easy enough to understand. But when you get a look at the transistor board you’ll see 24 of them in use. He’s included a 150 ohm resistor on the collector of each transistor. It must be set up to only allow one segment of each group to switch on at a time? We’d guess that each segment is divided into two (upper and lower pins are multiplexed separately), which would explain the double set of transistors. As for date and time, an Arduino board monitors a DS1307 RTC and manages the scanning of the display.

Incredible Fabrication Process Makes This Word Clock Stand Out

September 17, 2012 by Mike Szczys 13 Comments

From the look of it his is just another Word Clock, right? From the outside maybe. But if you take a look at the build photos this a good example of extreme fabrication.The design uses a five-layer lamination of glass bezel, vinyl lettering, diffuser, mounting plate, and back panel. The mounting and lettering layers were labor intensive, but are also the reason for the gorgeous finished look.

The bezel consists of black adhesive foil applied to the back of the glass faceplate. The letters were cut out using a vinyl cutter, and the lamination process happened in a pool of water. This technique helps to ensure that no fine particles end up between the glass and the foil.

The wooden mounting bracket was ordered from a local kitchen cabinet fabricator. It’s MDF that is 17.7″ and has been edge wrapped in glossy white PVC. Once it arrived, [Muris] started drilling the 248 holes and their counter sinks. This is on the front side of the layer and when sprayed with silver paint the countsinks act as reflectors. On the back side he milled groves to accept PCB strips to host the LEDs as well as the breakout boards that hold the MAX7219 drivers.

Don’t miss the video clip after the break that shows off the final product.

Continue reading “Incredible Fabrication Process Makes This Word Clock Stand Out” →

An Ice Tube Clock For The TI Launchpad

September 17, 2012 by Brian Benchoff 8 Comments

Because Nixies, Decatrons, and VFD tubes really are that cool, [cubeberg] over on the 43oh forums designed an IV-18 clock for the TI Launchpad.

Like adafruit’s Ice Tube clock, [cubeberg]’s project uses a surplus Russian IV-18 VFD tube conveniently sourced on eBay. On the board, there are three buttons for changing the time and setting the alarm along with a MAX6921 VFD tube driver and a small switching regulator to boost the 5 Volts on the Launchpad to the 50 V the tube requires.

There was a little bit of space left on [cubeberg]’s PCB design, and he filled that space with a header for a buzzer and a temperature sensor. Right now, the code doesn’t support an alarm function and he’s still waiting on a few components to finish off the thermometer portion of the board, but it’s still the makings of a very nice clock.

If you’d like to grab your own Launchpad ice tube clock, [bluehash] is organizing a group buy for 430h forum members. If they can get 15 pieces built, the clock will cost less than $5/unit. Very cool, and very cheap when you consider TI is practically giving Launchpads away.