DCF77 Powered Clock Is A Work of Art

December 6, 2013 by Mathieu Stephan 21 Comments

[Brett] just completed his DCF77 Master Bracket Clock, intended to be a backup to an old logic controlled clock he made. For our readers that don’t know, DCF77 is a German longwave time signal whose transmitter is located near Frankfurt (Germany). Every minute, the current date and time are sent on the 77.5kHz carrier signal.

The result, which you can see above, is made using an Ikea lantern, a skeleton clock, an ATmega328 (for Arduino compatibility), a voice recording playback IC (ISD1730), a cheap 20×4 LCD display, a DCF77 receiver module, and many LEDs. We’re pretty sure that it must have taken [Brett] quite a while to get such a nice looking clock. In case the clock loses power from the power supply, 3 AA cells provide battery backup. On the firmware side, making the platform Arduino-compatible allowed [Brett] to use its libraries so the coding was quickly done. Embedded after a break is a video of the final result.

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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]

DCF77 Signal Filtering And Decoding

December 4, 2012 by Mike Szczys 22 Comments

[Udo] decided to build a clock using the DCF77 radio module seen above. This of course has been done before: the hardware draws a clock signal from the atomic clock in Braunschweig, Germany. So he grabbed a library for Arduino and got to work. But he was getting rather poor results and upon further investigation realized that the library had been written for 20 Hz modules and his operates at 300 Hz. This means better accuracy but the drawback is that the hardware is more susceptible to noise.

So began his journey to filter, process, and decode the DCF77 protocol. That link goes to the project overview. It will be in several parts all of which will be linked on that page. So far he has applied a low-pass filter and coded some exponential smoothing. He has yet to write the other four parts, but does mention that early testing shows that this technique will make the reception better than what is achieved with commercially available clocks. He was able to lock onto a signal that had more than 80% noise ratio. That’s impressive!

Just want to see a clock that uses a DCF77 module? Check out this PIC-based atomic clock.

Hackaday Podcast Episode 268: RF Burns, Wireless Charging Sucks, And Barnacles Grow On Flaperons

April 26, 2024 by Dan Maloney 4 Comments

Not necessarily the easy way to program an EPROM

Elliot and Dan got together to enshrine the week’s hacks in podcast form, and to commiserate about their respective moms, each of whom recently fell victim to phishing attacks. It’s not easy being ad hoc tech support sometimes, and as Elliot says, when someone is on the phone telling you that you’ve been hacked, he’s the hacker. Moving on to the hacks, we took a look at a hacking roadmap for a cheap ham radio, felt the burn of AM broadcasts, and learned how to program old-school EPROMs on the cheap.

We talked about why having a smart TV in your house might not be so smart, especially for Windows users, and were properly shocked by just how bad wireless charging really is. Also, cheap wind turbines turn out to be terrible, barnacles might give a clue to the whereabouts of MH370, and infosec can really make use of cheap microcontrollers.

Grab a copy for yourself if you want to listen offline.

Continue reading “Hackaday Podcast Episode 268: RF Burns, Wireless Charging Sucks, And Barnacles Grow On Flaperons” →

A Clock Made Out Of Electromechanical Relays

February 13, 2024 by Maya Posch 11 Comments

Electromechanical circuits using relays are mostly a lost art these days, but sometimes you get people like [Aart] who can’t resist to turn a stack of clackity-clack relays into a functional design, like in this case a clock (article in Dutch, Google Translate).

It was made using components that [Aart] had come in possession of over the years, with each salvaged part requiring the usual removal of old solder, before being mounted on prototype boards. The resulting design uses the 1 Hz time signal from a Hörz DCF77 master clock which he set up to drive a clock network in his house, as he describes in a forum post at Circuits Online (also in Dutch).

The digital pulses from this time signal are used by the relay network to create the minutes and hours count, which are read out via a resistor ladder made using 0.1% resistors that drive two analog meters, one for the minutes and the other for the hours.

Sadly, [Aart] did not draw up a schematic yet, and there are a few issues he would like to resolve regarding the meter indicators that will be put in front of the analog dials. These currently have weird transitions between sections on the hour side, and the 59 – 00 transition on the minute dial happens in the middle of the scale. But as [Aart] says, this gives the meter its own character, which is an assessment that is hard to argue with.

Thanks to [Lucas] for the tip.

Rise And Shine With This Japanese-Inspired Clock

November 3, 2019 by Tom Nardi 4 Comments

On the Hackaday.io page for his gorgeous “Sunrise Alarm Clock”, [The Big One] is quick to point out that his design is only inspired by Japanese lanterns, and does not use authentic materials or traditional woodworking techniques. Perhaps that’s an important fact to some, but we’ll just say that the materials used seem far less important when the end result looks this good.

Unfortunately [The Big One] hasn’t provided any interior shots of his clock, as it sounds like the aesthetics of the internal wiring isn’t quite up to the standard set by the outside of it. But he has provided a concise parts list, a wiring diagram, and source code, so we’ve got a pretty good idea of what’s under the hood.

The clock is powered by the uBBB 32u4, an ATMega32u4 development board that [The Big One] developed in conjunction with [Warren Janssens]. It uses the popular MAX7219 LED matrix for the display, and a DS3231 RTC module to help keep the time. There’s also a DFPlayer Mini module onboard that allows him to play whatever sound effects or music he wants when the alarm goes off.

Of course the star of the show is the LED strips which illuminate the shōji-style column. These have apparently been wrapped around a coffee can of all things, which not only serves as a convenient way of holding the strips, but [The Big One] says actually makes the speaker sound a bit better. Hey, whatever works.

This isn’t the first “lantern” clock to grace these pages, but compared to the high-tech presentation of previous projects, we can’t help but be impressed by the grace and elegance of this wooden masterpiece.

Hackaday Podcast 036: Camera Rig Makes CNC Jealous, Become Your Own Time Transmitter, Pi HiFi With 80s Vibe, DJ Xiaomi

September 20, 2019 by Mike Szczys 5 Comments

Hackaday Editors Elliot Williams and Mike Szczys work their way through a fantastic week of hacks. From a rideable tank tread to spoofing radio time servers and from tune-playing vacuum cleaners to an epic camera motion control system, there’s a lot to get caught up on. Plus, Elliot describes frequency counting while Mike’s head spins, and we geek out on satellite optics, transistor-based Pong, and Jonathan Bennett’s weekly security articles.

Take a look at the links below if you want to follow along, and as always tell us what you think about this episode in the comments!

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (60 MB or so.)