Millivolt Meter Nixie Clock

October 25, 2011 by Brian Benchoff 9 Comments

Surprisingly, up until a year ago, [Jimmy] hadn’t seen a Nixie tube. Awful we know, but he has come around to the beauty of glowing numbers in a tube. He recently found an old millivolt meter in a junk pile that used Nixie tubes. The wondrous orange glow beckoned him, so [Jimmy] decided to build a clock.

Just about all of the Nixie clocks we’ve seen (including non-clock builds) rely on building a controller for the Nixie tubes. The controllers range from Nixie Arduino shields to the good ‘ol 74141 IC. [Jimmy] realized he didn’t need to bother with controlling the tubes in an already functional millivolt meter – he only needed to send the right voltage.

For his clock build, [Jimmy] used an Arduino to output a voltage through a bunch of resistor dividers. For example, if the time is 12:30, the output voltage will be 12.30mV. Using this technique, the values for the needed resistors don’t exist, so a little bit of PWM means the Arduino keeps fairly good time.

There’s one added bonus of [Jimmy]’s clock – because the voltage varies around 0.01mV, the finished project acts like a digital version of Lord Vetinari’s clock. It may not be perfect, but at least a nice piece of equipment was saved from the trash.

Build A Binary Wall Clock For Just A Few Bucks

October 13, 2011 by Mike Szczys 11 Comments

The weekend is almost here and if you’re looking for an afternoon project consider building your own binary wall clock. [Emihackr97] built the one you see above using parts on hand, but even if you put in an order for everything, it won’t cost you much.

He used a cardboard box as the housing for the clock, marking a grid for the LEDs on the face and drilling holes to house them. Two columns for hours and another two for minutes let the clock display 24-hour time with alternate firmware for 12 hour time. Since there are two buttons – one to set hours, the other to set minutes – a little coding would make it possible to select between the two either by clicking both buttons at once, or holding down one button.

[Emihackr97] is driving the display with an ATmega48, which is a pin-compatible replacement for the ATmega168/328. Those chips are the type most commonly found on Arduino boards an indeed this project is running the Arduino bootloader, but uses an ISP programmer and breadboarded circuit to keep the costs low. There are plenty of pins to drive the 13 LEDs directly, making the soldering quick and painless. Check out a demo clip after the break.

If you’re successful at this build and get the itch for something with more style, there’s a ton of ways to spice up the look of a binary clock.

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Building A Better Clock To Drive You Insane

October 12, 2011 by Brian Benchoff 24 Comments

[youtube=http://www.youtube.com/watch?v=YpqFU4SGe1Y&w=470]

[Simon] came up with an improved version of Lord Vetinari’s clock that begs to be installed in waiting rooms around the world.

Last week, we were introduced to a real-life Vetinari Clock that keeps regular time but ticks at irregular intervals. It’s a great way to turn someone’s mind into porridge, but the original build broke after a few weeks because of some limitations in the clock drive. [Simon] built a very minimal circuit does away with these problems.

Just as in the first build, a microcontroller pulses the second hand motor once every second. As for the random component of this build, the microcontroller has a puts 32 bytes into a 128 byte array. The array is checked 4 times a second, and if the byte is 1, the second hand is incremented. If the byte is 0, time stops for a little bit. [Simon] included the schematic, board layout and code if you’d like to build one yourself.

There are a few drawbacks to this design; the pattern of ticking and not ticking is hard-coded into the microcontroller. Even though the 32 second long pattern shouldn’t be noticeable by watching the clock, it’s not an entirely random solution. Judging from the comments on the original build, using radioactive decay to increment a second might be a bit uncalled for.

We would like to see a second hand that stops when you look at it though. Facial recognition, anyone?

Vetinari Clock Will Drive You Insane

October 6, 2011 by Brian Benchoff 47 Comments

Sometimes we need more psy ops in our life. Being an eminent fan of the Discworld series, Reddit user [rdmiller3] decided he needed to build Lord Vetinari’s clock. This fictional clock was placed in the waiting room for Lord Vetinari in several of the Discworld books. Although the clock keeps accurate time overall, it sometimes tics irregularly and out of sync. The reason? To whittle away the minds of whoever waits for Lord Vetinari.

The build uses a standard battery-powered analog clockwork. The ticking mechanism is just a magnet mounted inside a coil driven iron core. The coil leads were disconnected from the clock circuit and connected to digital inputs of an Arduino. With a few random() calls, the clock keeps accurate but random time.

Unfortunately, the clock stopped working after a few weeks because the 5 V from the Arduino was, “pounding it way too hard.” [rdmiller3] says a few resistors and LEDs for the voltage drop would make for a more reliable circuit, though. Check out the hard to watch video of the clock in action after the break.

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A Sunrise Clock For Those Cold, Dark Winter Mornings

October 1, 2011 by Mike Nathan 26 Comments

For most of the working world, the onset of autumn and winter in the Northern hemisphere means one thing – waking up well before the sun rises to get a start on the daily grind. [Brent] from Freeside Atlanta knows that routine well and decided to build himself a sunrise alarm clock in an attempt to wake himself more naturally on those dark mornings.

He bought an assortment of LEDs in varying colors including blue, red, yellow, and white, along with a few UV diodes for good measure. His goal with this array of LEDs was to simulate the natural colors of the sunrise, rather than simply slowly brightening the room. The clock uses a DS1307 RTC to keep the time, and an Arduino is tasked with lighting the LEDs about 25 minutes before it’s time for [Brent] to wake up.

He says that it seems to be working pretty well, gently waking his body before the clock radio kicks in. It certainly beats a loud buzzer!

What Has 114 LEDs And Is Always Running?

September 29, 2011 by Mike Szczys 27 Comments

The answer, of course, is a word clock. This is actually [Eric’s] second version of a word clock. Like the first one, it uses 114 LEDs to back light the words on the display.

In his first iteration he used an Arduino to drive a Charlieplex array of lights. It was an 11 by 10 grid, plus four LEDs to display the in-between minutes as dots at each corner of the clock face. This time around he’s still using an Arduino, but the lights have seen a huge upgrade. In one of his build pictures you can see the reel of RGB led modules which have two RGB LEDs and an HL1606 driver on each segment. These are SPI controlled, making them easy to hook up, using just a few data and power bus rails. Check out the test video after the break that shows what this grid is capable of.

In case you can’t figure out what time is displayed above, you might check out an English version of a Word Clock face to help in your own build.

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Putting Twitter In A VFD Clock

September 29, 2011 by Brian Benchoff 1 Comment

Not content with only knowing the time, [trandi] decided his Vacuum Fluorescent Display clock would be much better if it displayed the weather and a Twitter feed.

[trandi] received a Lady Ada Ice Tube clock last month. The kit went together almost too easily. Now he had to, “make it connect to other ‘stuff’ and display some custom messages.” After playing with the firmware to display a Hello World, [trandi] mucked around with the GPS mod and figured out how to add scrolling text over a serial connection.

A serial connection to an Internet-connected computer is all well and good, but [trandi] really wanted a stand-alone solution. A tiny WiFi to RS-232 board was sourced and the work of getting a clock on the internet began in earnest. After a weekend was wasted trying to debug the HTTP mode of the WiFi board, [trandi] gave up and used TCP mode with manually constructed HTTP headers.

The clock gets the current weather and a Twitter feed. To one-up to the Ice Cube GPS mod, the clock now sets its own time from the Internet. Check out the video of [trandi] showing off his Internet clock and fine collection of single malts after the break.

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