Here at Hackaday we have a bit of a preoccupation with timepieces. Maybe it’s the deeply personal connection to an object you wear on your body, or the need for ultimate reliability. Perhaps it’s just a fascination with the notion of time itself. Whatever the case, we don’t seem to be alone as there is a constant stream of time-related projects coming through our virtual doors. For this article we’ve unearthed the LED Pocketwatch 1.0 by [Dr. Pauline Pounds] from way back in 2009 (ironically via a post about a wristwatch from last year!). Fortunately for us the Internet Archive has saved this heirloom nouveau from the internet dustbin so we can appreciate the craftsmanship involved in [Dr. Pounds]’ work.
My how far we’ve come; a decade after this project was posted a hacker might choose to 3d print a case for a new wearable, but in 2009 that would have been an entire project by itself! [Dr. Pounds] chose to use the casing from an antique Elgin pocket watch. Even through the mists of a grainy demo video we can imagine how soft the well-worn casing must be from heavy use. This particular unit was chosen because it was a hefty 50mm in diameter, leaving plenty of room inside for a 44mm double sided PCBA with 133 0603 LEDs (60 seconds, 60 minutes, 12 hours), a PIC 16F946, an ERM, and a 110mAh LiPo. But what really sets the LED Pocketwatch 1.0 apart is the user interface.
The ERM is attached directly to the rear of the case in order to best conduct vibration to the outside world. For maximum authenticity it blips on the second, to give a sense that the digital watch is mechanically ticking like the original. The original pocket watch was designed with a closing lid which is released when the stem is pressed. [Dr. Pounds] integrated a button and encoder with the end of the stem (on the PCBA) so the device can be aware of this interaction; on lid open it wakes the device to display the time on the LEDs. The real pièce de résistance is that he also integrated a minuscule rotary encoder, so when the stem is pressed you can rotate it to set the time. It’s all quite elegantly integrated and imminently usable.
At this point we’d love to link to sources, detailed drawings, or CAD files, but unfortunately we haven’t found any. If this has you inspired check out some of the otherpocket watches we’ve posted about in the past. If you’re interested in a live demo of the LED Pocketwatch 1.0, check out the original video after the break.
In a project that was really only slighly less creepy before the singer’s untimely death in 2017, this alarm clock built by [Rafael Mizrahi] awakens its user to a random selection of Chris Cornell’s signature screams. Not content to be limited to just the audio component of the experience, he contained all of the hardware within a styrofoam head complete with a printed out facsimile of the singer’s face.
An Arduino Uno coupled with a seven segment LED display provides the clock itself, which is located in the base. There’s no RTC module, so the Arduino is doing its best to keep time by counting milliseconds. This means the clock will drift around quite a bit, but given that there’s also no provision for setting the time or changing when the alarm goes off short of editing the source code, it seems like accurate timekeeping was not hugely important for this project.
Audio is provided by an Adafruit VS1053, which contains a microSD card full of MP3 samples of Cornell’s singing. This is connected to an X-Mini portable capsule speaker which has been installed in a hollowed out section of the foam.
Until the 1960s, watches and clocks of all kinds kept track of time with mechanical devices. Springs, pendulums, gears, oils, and a whole host of other components had to work together to keep accurate time. The invention of the crystal oscillator changed all of that, making watches and clocks not only cheaper, but (in general) far more accurate. It’s not quite as easy to see them in action, however, unless you’re [noq2] and you have a set of strobe lights.
[noq2] used a Rigol DG4062 function generator and a Cree power LED as a high-frequency strobe light to “slow down” the crystal oscillators from two watches. The first one he filmed was an Accutron “tuning fork” movement and the second one is a generic 32,768 Hz quartz resonator which is used in a large amount of watches. After removing the casings and powering the resonators up, [noq2] tuned in his strobe light setup to be able to film the vibrations of the oscillators.
It’s pretty interesting to see this in action. Usually a timekeeping element like this, whether in a watch or a RTC, is a “black box” of sorts that is easily taken for granted. Especially since these devices revolutionized the watchmaking industry (and a few other industries as well), it’s well worthwhile to take a look inside and see how they work. They’re used in more than just watches, too. Want to go down the rabbit hole on this topic? Check out the History of Oscillators. Continue reading “Strobe Light Slows Down Time”→