Modernizing a 170 year old Antique Grandfather Clock

Frankly, we let out a yelp of despair when we read this in the tip line “Antique Grandfather clock with Arduino insides“! But before you too roll your eyes, groan, or post snark, do check out [David Henshaw]’s amazing blog post on how he spent almost eight months working on the conversion.

Before you jump to any conclusions about his credentials, we must point out that [David] is an ace hacker who has been building electronic clocks for a long time. In this project, he takes the antique grandfather clock from 1847, and puts inside it a new movement built from Meccano pieces, stepper motors, hall sensors, LEDs, an Arduino and lots of breadboard and jumper wires while making sure that it still looks and sounds as close to the original as possible.

He starts off by building a custom electro-mechanical clock movement, and since he’s planning as he progresses, meccano, breadboard and jumper wires were the way to go. Hot glue helps preserve sanity by keeping all the jumper wires in place. To interface with all of the peripherals in the clock, he decided to use a bank of shift registers driven from a regular Arduino Uno. The more expensive DS3231 RTC module ensures better accuracy compared to the cheaper DS1307 or similar clones. A bank of RGB LEDs acts as an annunciator panel inside the clock to help provide various status indications. The mechanical movement itself went through several iterations to get the time display working with a smooth movement of the hands. Besides displaying time, [David] also added a moon phase indicator dial. A five-rod chime is struck using a stepper motor driven cam and a separate solenoid is used to pull and release three chime hammers simultaneously to generate the loud gong sounds.

And here’s the amazing part – he did all of this before laying his hands on the actual grandfather clock – which was shipped to him in California from an antique clock specialist in England and took two months to arrive. [David] ordered just the clock housing, dial/face and external parts, with none of the original inner mechanism. Once he received it, his custom clock-work assembly needed some more tweaking to get all the positions right for the various hands and dials. A clock like this without its typical “ticktock” sound would be pretty lame, so [David] used a pair of solenoids to provide the sound effect, with each one being turned on for a different duration to produce the characteristic ticktock.

At the end of eight months, the result – christened Judge – was pretty satisfying. Check the video below to judge the Judge for yourself. If you would like to see some more of [David]’s clockwork, check out Dottie the Flip Dot Clock and A Reel to Reel Clock.

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Get Inside a TCXO Clock Chip

[Pete] wondered how real-time clock modules could be selling on eBay for $1.50 when the main component, the Maxim DS3231 RTC/TCXO chip, cost him more like $4 apiece. Could the cheap modules contain counterfeit chips?

Well, sure they could. But in this case, they didn’t, and [Pete] has the die shots to prove it. He started off by clipping the SOIC leads rather than desoldering — he’s not going to be reusing this chip after he’s cut it in half. Next was a stage of embrittling the case by heating it up with a lighter and dunking it in water. Then he went at it with sandpaper.

It’s cool. You can see the watch crystal inside, and all of the circuitry. The DS3231 includes a TCXO — temperature-corrected crystal oscillator — and it seems to have a bank of capacitors that it connects and disconnects depending on the chip’s temperature to keep the oscillator running at the right speed. [Pete] used one in an offline situation, and it only lost sixteen seconds over a year, so we’d say that they work fine.

If you’d like to know more about how crystals are used to keep time, check out [Jenny]’s excellent article. And if sixteen second per year is way too much for you, tune up your rubidium standard and welcome to the world of the time nuts.

Power Sipping Master Keeps Slave Clock on Time

Few things are as infuriating as clocks that are not synchronized. It’s frustrating when the clock on the range and the clock on the microwave act like they’re in time zones that are one minute apart. Now picture that same issue over dozens of clocks in a train station, or hundreds in a school or factory. It’s no wonder that slave clocks, which advance on signals from a master clock, were developed.

When a pair of vintage Lepaute slave clocks made their way to [melka], he knew just what to do – build his own master clock to keep the slave on track. This particularly stylish slave clock uses pulses of alternating polarity every 30 seconds and will work on 1.5-volt pulses, which let [melka] meet his design goal of running for a year off a single AA battery. To keep the power needs low, [melka] relies on the RTC to wake up the MSP430 every second to increment a counter. When it hits 30, a pulse is sent to the clock’s motor through an H-bridge; the MCU alternates the polarity of every other pulse to advance the clock.

It’s not immediately clear how the clock is set; we recall the slave clocks in high school rapidly advancing for Daylight Saving adjustments, so we assume [melka] has provided some way of pulsing the clock quickly to set the time. Regardless, it’s a good lesson in low-power design. And be sure to check out this PIC-based master clock replacement, too.

7 Segment Display Using Neopixel Rings

There’s something about clocks — sooner or later, every hacker wants to build one. And we end up seeing all kinds of display techniques being used to show time. For the simplest of builds, 7-segment display modules usually get dug up from the parts bin. If you have a bunch of “smart” LED’s (WS2812’s, APA102’s), then building your own custom 7-segment modules isn’t too difficult either. [rhoalt] had neither, but he did have several 8 LED Neopixel rings lying around. So he thought of experimenting with those, and built a ‘Binoctular’ LED clock which uses the Neopixel rings as 7 segment displays.

figure-eight-segment-displaysEach digit is made using one pair of Neopixel rings, stacked to form a figure of eight. All the digits are composed of arcs, so readability isn’t the best but it’s not hard either. [rhoalt] does mention that the display is easier to read via blurred camera images rather than visually, which isn’t surprising. We’re long used to seeing numbers composed of straight line segments, so arc segmented digits do look weird. But we wouldn’t have known this if [rhoalt] hadn’t shown us, right ? Maybe a thicker diffuser with separator baffles may improve the readability.

The rest of the build is pretty plain vanilla — an Arduino Nano clone, a DS3231 RTC, a Lithium battery, and some buttons, all housed together in a laser cut enclosure which follows the figure of eight design brief. And as usual, once you’ve built one, it’s time to improve and make a better version.

Alarm System Upgrade Tips The Functionality Scale

Residential-grade commercial alarm systems are good at a few things but terrible at others, like keeping pace with telephone technology. So what to do when a switch to VOIP renders your alarm system unable to call in reinforcements? Why not strip out the old system and roll your own value-added alarm and home automation system?

Generally, the hardest part about installing an alarm system is running the wires to connect sensors to the main panel, so [Bill Dudley] wisely chose to leverage the existing wiring and just upgrade the panel. And what an upgrade it is. [Bill]’s BOM reads like a catalog page from SparkFun or Adafruit – Arduino MEGA 2560, Ethernet shield, a sound board, stereo amplifier, X10 interface, and a host of relays, transformers, and converters. [Bill] is serious about redundancy, too – there’s an ESP8266 to back up the wired Ethernet, and a DS3231 RTC to keep the time just in case NTP goes down. The case is a bit crowded, but when closed up it’s nicely presentable, and the functionality can’t be beat.

Rehabilitating old alarm systems is a popular project that we’ve covered plenty of times, like this Arduino upgrade for a DSC 1550 panel. But we like the way [Bill] really went the extra mile to build add value to his system.

A Laser Cut Word Clock

DIY laser cut word clock.

What is a word clock? A word clock is a clock that displays the time typographically that is also an interactive piece of art. Rather than buy one for $1500, [Buckeyeguy89] decided to build one as a present for his older brother. A very nice present indeed!

There are many different things that come into play when designing a word clock. The front panel is made from a laser cut piece of birch using the service from Ponoko. Additionally, white translucent pieces of acrylic were needed to keep each word’s light from bleeding into the neighboring letters. The hardware uses two Arduinos to control the LEDs and a DS3231 RTC for keeping accurate time. The results are very impressive, but it would sure make assembly easier if a custom PCB was used in the final version. For a one-off project, this makes a great birthday present.

The craftsmanship of this word clock is great, making it well suited for any home. What projects have you built that involve more than just electronics? Sometimes, quality aesthetics make all the difference.

LED clock lights up a dead Mac Mini

[Professor Shadoko’s] Mac Mini died. But since the case designs on Apple products are half the reason to buy them, he decided to reuse the enclosure by turning it into this clock (translated).

As with the binary clock we saw yesterday, this one uses a bunch of LEDs to display the time, but it does it in a way that’s a bit more readable if you know what you’re looking for. The face has been divided up into two columns. On the left is hours, then minutes and seconds in increments of five. To the right is AM/PM, with minutes and seconds in increments of one. If we’re doing this right, the time seen above is 10:23:42 PM on April 28th, 2012. The white LEDs below the date act as a digital pendulum, scrolling left and right as the seconds tick by.

The display uses two MAX7219 LED drivers to control the grid which is build on a big hunk of protoboard. An Arduino ties the whole system together with a Chonodot for accurate time keeping. There’s even an ambient light sensor which adjusts the LED intensity to make this readable in direct sun, or the dark of night. See a demo clip embedded after the break.

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