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Project - DCF77 decoder with demo project


DCF77 decoder with demo project

In Europe you can receive a time signal at 77.5 kHz. I connected one receiver that you can buy here at a local electronic supplier to a gadgetee socket and wrote a small modules that decodes the received time informatione.

The demo project is a clock that is synchronized every hour with the DCF77 time. The protocol is publicly available, for example here:

There are also other radio stations transmittig the encoded time:


@ Stefan Heesch - Thanks for sharing your nice tools.


Great work.
I have a questions. Reading the code, I didn’t notice any seconds handling. I guess that DHC77 doesn’t support seconds reading, but i want to be sure.


Yes, DCF77 sends a second impuls.
A short impuls (100msec) represents a logic LOW.
A long impuls (200msec) represents a logic HIGH.
On the 59th second there is no impuls. This acts as a sync.

Cu Wim


Hello Stefan,
pls, can you give me any contant of you? I need help with read data from DCF module.
Thank you


hi @ Hawkcz, feel free to post your questions here, I’m sure someone here can give you some pointers as well… what problem have you hit?