VEEB Projects' Clock Pulls in "Atomic-ish" Signals to Turn a Raspberry Pi Pico Into a "Mother" Clock

from hackster.io

Design collective VEEB Projects is back with a new design built around the Raspberry Pi Pico microcontroller board: an "atomic-ish" driver for a retro secondary clock system.

"Reinvigorating a handsome old clock and making it super-accurate, without any internet," the collective writes of the project, simply called Clock. "Uses a Raspberry Pi Pico, a radio antenna, and a couple of components to emulate a signal from a mother clock."

The analog clock being driven in the project has no time-keeping capabilities of its own; instead, it's designed to be used with the aforementioned "mother clock" — a central device that sends timekeeping signals to any number of secondary clocks, ensuring they all stay in sync.

The project gets its "atomic-ish" designation by using the DCF77 radio time signal, which transmits timing information from high-accuracy atomic clocks — giving the Clock the ability to automatically set itself to the current time without any form of connectivity to the internet.

"The [DCF77] signal covers most of Europe and is accurate to within a second over about 300,000 years," the collective notes. "The DCF77 signal has been broadcasting since the time since the 1973 and in 2021 it was agreed to be continued for at least 10 more years. The United States uses WWVB, United Kingdom uses MSF and Japan uses JJY. You could easily adapt the code to any of those signals."

Aside from the Raspberry Pi Pico, a low-cost development board build around the popular RP2040 microcontroller, the project uses a simple ferrite receiver antenna, an H-bridge, and the secondary clock — plus a more modern real-time clock chip, designed as a backup in case the radio signal is lost.

The Python source code for the project is available on GitHub under the reciprocal GNU General Public License 3.