DCF77 Powered Clock Is A Work of Art

[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.

21 thoughts on “DCF77 Powered Clock Is A Work of Art

    1. Thanks for the kind comments. I take your points about the Blue LCD display a white on Black or even an E Ink display (if you can get them) would look very nice.

      I have just had a look at your pages. The DCF77 pulse ticking effect would work very well as a case back light. The whole case and movement would pulse to the DCF77 code.

  1. Very nice, but not ISO 8601 compliant. It needs to display date/time as “YYYY-MM-DD HH:MM:SS” to be truly global and not local proprietary. (very simple change in the arduino code so personal preference can reign supreme. :-) ) Yes, I’m a bit CDO (similar to OCD but the letters are in the right order)

      1. Perhaps I can win you over to my side with this statement. (or not :-) ) If you use “YYYY-MM-DD HH:MM:SS” to represent date/time for a list of events it sorts nicely chronometricly. I often write report code off of databases and it is usually good to sort data by time and this does so naturally. As for the clock, I have a penned up desire to make something similar as a grandfather clock with real chimes, pendulum, gears and hands but with an NIST precise timing system and some kind of way to power it with gravity so I don’t have to plug it in. I would just have to pull chains once a week. :-)

          1. Forgot to mention. I have seen an electric clock on You Tube that uses an electromagnet to keep the pendulum in sync. On my grandfather clock I have disabled the chime and I use an old 30 sec pulse clock movement with a bell hammer on the armature to strike the bell by pulses from my master clock. I have sampled this chime and play it back through my other clocks. As they are all in sync they all chime together.

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