Recently I bought a kit for a binary clock from pollin. Like with my other self-made digital clocks (from the university's lab excercise), I got annoyed by the need to set the time manually (especially for spring forward and fall back). For those, I had already added support for a DCF77-receiver, so the solution is obvious: add a DCF77-receiver also here.
The clock's hardware is similar to the one from the lab:
- multiplexed display
- two buttons for setting the time
- plenty of pins unconnected.
- Only real difference: The bought clock uses an ATTiny2313 - my personal favourite micro controller - instead of P16f872 in the lab clock.
Here is the code - of course with some intentional (and probably also unintentional) bugs:
- Minutes including leap seconds will not be recognized.
- There is no attempt to correct radio errors - the decoder logic is really strict.
The complete, assembled clock (some parts for mounting the PCB and ferrit core have been 3d-printed by a friend):