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.

Deathly Hallows Mark The Passing Of Time

January 14, 2013 by Mike Szczys 3 Comments

Whether you’re a Harry Potter fan or not we think you’ll enjoy this Deathly Hallows clock. The body is modeled after the triangle, circle, and line that make up the symbol that played a prominent role when concluding the fantasy novel series. A bit of motion and a couple handfuls of LEDs are what allow it to display the time of day.

[Yeenasty] started by building the triangular surround out of wood. In the center he added a circular veneer which was partitioned into twelve chambers. These indicate the hour and are illuminated one at a time from midnight until noon. Once all of the LEDs are switched on (as seen above) they are then extinguish one at a time from noon until midnight. [Yeenasty] mentions that this means the clock isn’t overly bright during the night-time hours.

Minutes are displayed by the wooden slat in the middle of the ring of LEDs. Here it’s showing 30 minutes after the hour because it is vertical and the bottom red LED is lit. The hand is mounted on a 180 degree servo so when it has made half of a rotation the hand backtracks 29 minutes and the LED at the other end is illuminated to continue progress around the face of the clock.

[via Reddit]

Super Slim Wristwatch Build

December 12, 2012 by Mike Szczys 33 Comments

This slmwtch lives up to its name. When the LCD screen is folded back onto the PCB the entire thing comes in at just 2.35mm. That’s including a coin-cell battery not shown above. Wow!

Part of what makes this possible is the specialized PCB design. [Anders] didn’t want to add more thickness than the screen and battery so he make a cutout in the PCB design to accept each component. In this image it’s easiest to see on the two SMD resistor in the upper left. They’re held in a void by the two solder connections. Admittedly this is not going to be a mass-production friendly design. And we have concerts about the long-term stability of suspending components by their leads. But as a one-off it’s fantastic! See for yourself in the video after the break.

The control for the watch uses two touch sensitive pads on the back of the PCB. There is no backlight for the display which can be a problem when trying to read the time while outdoors. We wonder if an ePaper display with similar dimensions is available?

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Sunrise Alarm Clock Uses DCF77 For Perfect Time

December 6, 2012 by Mike Szczys 10 Comments

Here’s a sunrise alarm clock that keeps perfect time. It was designed and built by [Renaud Schleck] who also published a post detailing the process.

As you can see, a series of white LEDs inside of the transparent case which provide the simulated sunrise. As the days get short and the nights longer we do see the benefit of having your clock brighten the room before it jolts you out of your slumber. Speaking of, that alarm sound seems to be the weak link in his design. He’s using a square wave smoothed with capacitors to drive a speaker at either end of the case. We didn’t hear an example but we imagine this not the most gentle of sounds.

The rest of the design is quite well done. He’s using a 4×20 Character LCD display and adjusts the backlight using PWM. A DCF77 radio feeds data from an atomic clock signal to the MSP430 chip which runs the clock. There’s even a battery backup in case the power goes out.

We just saw a project yesterday that aims to improve signal quality with a DCF77 radio.

[via Reddit]

The Beginnings Of A Geeky Wristwatch

December 5, 2012 by Mike Szczys 18 Comments

Wow, we’re seeing all kinds of good stuff from NYC Resistor today. [Caleb] found this link to [Hudson’s] early work on a geeky wristwatch. It is based around an HDSP-2112 eight-digit alpha-numeric display. Each digit is a 5×7 array of LEDs, but the look of it really reminds us of [Woz’s] Nixie Wristwatch. The nice thing about using a display like this one is it’s much easier to drive and the power requirements don’t really call for special consideration either.

The display happens to be nearly the same footprint as the Teensy 2.0. In fact, the display is a bit longer. That makes it a perfect backpack, bringing everything necessary to drive the display. Check out the video after the break to see it scrolling the time as words, and displaying numbers.

This needs to have an RTC and portable power source before you can wear it around. But the proof is there. Perhaps [Hudson] will spin his own board with a uC that includes RTC capability and a charging circuit for a tiny Lithium cell.

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Minecraft Clock Radio Puts A Creeper Head Next To Your Bed

November 30, 2012 by Mike Szczys 3 Comments

This clock radio plays tunes from Minecraft and it’s decorated to look just like a creeper head. In the game mob heads are available as decoration and [Young_Maker] liked to spice up his virtual bedside table with a creeper head. But we think it looks just as good in its physical form.

The main part of the clock is an Arduino with a character LCD screen. A DS1307 real-time clock makes sure the device is accurate. We called this a clock radio in the title of the post, but it’s more of a clock MP3 player. The uMp3 board is used to play random music from the game. We would categorize the soundtrack as minimalism, which is a reasonable way to gently wake in the morning. But if time runs out the boom of an exploding creeper is played to make sure you’re not late for work.

We’ve embedded [Young_Maker’s] demo video after the jump.

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