Make Your Own Atomic Clock

We see plenty of clock projects come through, but usually it is their visual or mechanical design that stands out. The DCF-77 LED PIC clock is fun because it is synchronized with the Atomic clock in Braunschweig Germany. The clock picks up the radio signal at 77.5 KHz known as DCF77, and that’s where it got its name.

The circuit looks surprisingly simple and usually costs less than $30 to build, depending on how you piece it together. You can download the schematics and code from the site, but you may have to do a little research about how to catch the signal from your location. The person who wrote this was located in Europe.

[found via HackedGadgets]

30 thoughts on “Make Your Own Atomic Clock

  1. Make your own Atomic clock?

    Next week on Hackaday: Make you own Atomic Bomb!
    (actually just a crappy arduino hack that allows you to display video of an atomic explosion on a crappy nokia phone display)

    1. An atomic clock and The Bomb are completely different. The clock “movement” does not need radioactivity while The Bomb needs the fissible material. The atomic clock was actually invented before we invented The Bomb that gave the Japanese the hint. If you can run an Arduino on 10MHZ you can have a “nuke clock”. What you want is a Rubidium frequency standard, easy to find om eBay for ~ a C Note. ($100)

      How accurate a clock do you want? The more accurate the better!

  2. Agreed. This is making an atomic clock like buying a laptop is making the internet.

    Not to say this is not a useful trick. If commercial clocks used this for say a dollar per unit, we would never have to set a clock again.

  3. In the USA, the corresponding longwave time signal is called WWVB. A groundwave is preferred over shortwave skip because the radio wave path is constant and predictable.

    WWVB isn’t to hot a signal on the east coast though.

    The real advantage in a clock like this is that it can be made to set itself and deal with daylight savings time. Aside from that though, seriously, for clock/radio/alarm level precision you can usually trust the power company to issue 5,184,000 power peaks per day, and then just divide that down.

  4. Very nice. What I’d really like to see is a clock that transmits the WWVB or DCF signal. In my country there is neither of these signals, but I do have several gadgets that can “listen” for these signals.


  5. Keep on mind this will only work in Europe, and only in reasonable distance from the sender.
    Commercial clocks with this receiver are available for a couple of bucks, and I’ve even seen wristwatch using DCF77.

  6. These days, synchronization via DCF-77 is a really common feature for alarm clocks, weather stations and wall clocks here in Europe. Cheap DCF-77 clocks (“Funkuhr” in German) can be bought for around 10€. So, you’re essentially saying that there are a few million atomic clocks around here ;)

  7. Has the rest of the world gone on night time robing time like the US, or is the time soon. We shifted two weeks ago and on cue we went from frosty to eighty’s overnite and kept it going till yesterday.
    My way of protesting this situation with clocks is to use UTC.
    It’s fun to hear voice time on WWVB and WWVH mixing together on 10 or 15 mHz, and hear him (Colorado) and her (Hawaii!) pipping along out of time like John Lennon’s Give Peace A A Chance clap track.

  8. I have a working LIDL DCF clock however with some problems due to reception. I’m at Lisbon so far away from Germany
    so the signal change very much from acceptable to nothing from summer to winter. So today I’m using a GPS clock I adapted
    from an old SONY photo tagher and works very whell.

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