Being inspired by some articles at the internet, I liberated
an old Russian military frequency counter from the attic and reused its famous "Nixie" tubes
to build a retro-look clock controlled by an Arduino™ board. Below are some links to various
items from that project. All of these can be freely downloaded, modified and distributed.
Software snippets/libraries (tested on Arduino™ Leonardo & Nano):
To design your own Arduino™-based atomic clock, you may implement the C-library provided under the below link
as a beginning. The program decodes the signal coming from a "DCF77" receiver. In order to work, the two
none-standard libraries "Time" and "BitArray" must be loaded, too. Both are already added to this package.
Please consult the Arduino™ project page in order to learn how to add libraries to the Arduino™
In semiconductor age driving a Nixie tube can be quite a challenge. Nixies should not be multiplexed in
order to prevent them from aging quite rapidly. Hence, hardware efforts are typically big. In addition
there is the issue of having to control voltages higher than most nowadays ICs can handle. In the case of
my clock I decided to apply a slightly different concept, using a low-power MOSFET for both, high-voltage switching
and data buffering. This approach somewhat resembles a DRAM memory, where information is being held temporarily by
charged capacitors which have to be refreshed at some interval. The resulting design is quite cheap, compact
and robust. The sketch under the below link is only meant for inspiration. There surely are many
other possible ways of implementation. If you are interested in the code controlling this hardware or have
questions related to the concept itself, just send me a message.
Looking for a good-sounding and freely available clock-chime at the internet actually turned out
to be quite hard. Perhaps I was too demanding ...Whatever, here comes my self-synthesized sound
of a Grandfather's clock chiming 12 (WAV / mono / 16bit resolution / 44.1kHz sampling rate /
max. frequency 3kHz / 29.5s / each chime 2s + 0.5s seconds of silence).