Lord Vetinari’s Clock Strikes Again

February 12, 2013 by Mike Szczys 15 Comments

Inspired by the maddening timepiece from Discworld, this clock keeps time, but anyone watching the seconds tick by may be mentally unstable for it. [Renaud Schleck] built the stuttering clock using very few components. He undertook the build after being inspired by the version which [Simon Inns] built.

The clock itself is a run-of-the-mill item which uses one battery to keep time. We’re always impressed by how these dirt-cheap things remain so accurate over the long haul — but we digress. The method of attack uses coil injection to drive the hands. [Renaud] used one of the microcontrollers from the MSP430 Launchpad, along with the clock crystal which also shipped with the kit, to gain control of the mechanism. The crystal triggers an interrupt which does the actual time-keeping. The seconds hand is driven rather sporadically based on an algorithm explained in his write-up.

You can watch the uneven ticking in the video after the break. Despite that visually disturbing functionality, the short and long ticks balance each other and the correct time continues to be displayed.

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GLCD Clock Project Packed With Great UI And Features

February 11, 2013 by Mike Szczys 4 Comments

This Graphic LCD clock doesn’t have a fancy case, but [Gregory Wright] built in so many great features we think it will serve as inspiration for many projects to come. If he does decide to add a case it will be quite easy as there are no buttons to work around.

Without buttons how can the thing be adjusted? He decided to go with an IR remote control for all settings. This gives him a lot more options than a handful of buttons would have. Plus, heavy sleepers will need to find the remote control in order to shut off the alarm. We also think it’s interesting that the 595 shift registers he used have a low enough data high threshold (3.15V when VCC is 4.5V) that he didn’t need level converters to drive the 5V display with his 3.3V MSP430 Launchpad.

Check out his video after the break to learn about all the features he included in the UI. Our favorite is shown on the bottom right where it says “Hello World”. This is an area dedicated to a custom message for each day. He uses it to remind him about trash day (now there’s a feature!).

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HDD POV Clock Takes The Best From Those That Came Before It

January 30, 2013 by Mike Szczys 5 Comments

The concept behind this clock has been seen before, but [Dieter] tried to combine the best aspects of several projects into his HDD POV clock (translated). The basic principle of the design is to cut a slot into the top platter of the hard drive. This will let the light from some LEDs shine through. By carefully synchronizing the LED with the spinning platter a set of differently colored hands can be shown to mark time. We’ve been looking at the project for several minutes now and we’re not quite sure if the lines marking the 5-minute segments on the clock are generated in the same way as the hands, or if they’re marks on a faceplate on top of the platters. Check out the clip after the break and let us know what you think.

Past HDD clock project include this one, or this other one. Some of the design improvements include a better motor driver (which [Dieter] pulled from an old VCR) and the inclusion of an RTC chip to keep accurate time without the need to be connected to a computer. We also think it’s a nice touch to sandwich the hardware between two picture frames for a nice finished look.

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Sunrise Alarm Clock Mounted Above The Bed

January 25, 2013 by Mike Szczys 12 Comments

This sunrise alarm clock was made in a bit different form factor than we normally see. Instead of a box next to the bed it’s a bar above the headboard which slowly illuminates every morning. This was [Holly’s] first electronics project. She spent pretty much all summer working on it and accumulated a skill set that included designing for and operating the laser cutter and assembling and programming the electronics.

She didn’t start from square one. The hardware and programming were greatly simplified by the availability of RGB LED strips and the Monochron clock which drives them. [Holly] altered the code to bring up a blueish hue over a 35-minute time period. Since this will be used to wake her at 5:30am she was also obliged to include some backup sounds just in case. But after the project was finished and mounted she forgot to turn them on and was pleasantly surprised that the lights woke her up on time. The mounting bracket seen above uses t-slot rail with laser cut brackets to hold the half-cylinder shade for the sconce. The final product looks fantastic!

Retrotechtacular: How A Watch Works

January 23, 2013 by Mike Szczys 31 Comments

Anyone who has ever tried to keep time with an electronic project will have respect for a timepiece that stays accurate over the span of months or more. We think it’s even more respectable when it comes to mechanical watches. This video was made by the Hamilton watch company back in 1949 to explain the basic processes behind a precision mechanical timepiece.

It takes several minutes to get to the meat of the presentation, but we think you’ll find the introduction just as entertaining as the explanation itself. When it does come time to look inside the watch a set of large pieces is used to help illustrate the workings of each part. The clip (which is also embedded after the break) does a great job with these demonstrations, but almost immediately you’ll come to realize the complexity wrapped up in an incredibly tiny package. It goes on to explain the low-friction properties that are brought to the table by the jewel bearings. Enjoy!

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Award Clock Put To Good Use As A Bench Meter

January 21, 2013 by Mike Szczys 6 Comments

The motivation industry turns out these type of award trinkets by the millions. Here’s a way to actually put the thing to use. Instead of displaying time, the clock dial serves as the readout of a voltage meter.

When we first saw this post we assumed that the hack used some type of coil injection to drive the hands. But it turns out that this is mechanically driven. The image above shows the stepper motor which is mounted behind the clock. Its drive shaft is coupled with the adjustment knob on the back of the clock. The precision of the motor lets the PICAXE set the clock dial based on the number of motor steps. The hour hand shows the tens value with the minutes serving as ones (base 10, not base 60). This means the top measurable voltage is 12V — when the hour hand is at 12 the measurement is 0 volts plus tenths of a volt from the minute hand. With the dial taken care of the rest of the project focuses on measuring the voltage using the ADC, which has an upper limit of just 5V. This is overcome with a simple voltage divider.

After the break you can see the accuracy of the rig as it performs measurements next to a digital voltmeter.

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Hacking Grandfather Clock Accuracy While It’s Still Ticking

January 15, 2013 by Mike Szczys 36 Comments

[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.