[Cameron Meredith] starts the Hackaday.io page for one of his projects by quoting a Hackaday write-up: “A timepiece is rather a rite of passage in the world of hardware hacking“. We stand by that assertion, but we’d say most of the clocks we feature aren’t as capable as his project. He’s made a real-time-clock module controlled by a rubidium frequency standard, and since it also includes a GPS clock he can track local time dilation effects by comparing the two.
Surplus rubidium standards are readily available, but each description of one seems to feature a lot of old-fashioned hardware hacking simply to get it working. This one is no exception, an unusual connector had to be replaced and an extra power supply module attached. Once those modifications had been made and a suitable heatsink had been attached, he was able to bring the rubidium standard, an RTC module, and GPS module together with an ATMega32U4 miniature Arduino-compatible board and an LCD display. The firmware is functional, but he admits it is not finished.
All the project’s files can be found on the Hackaday.io page linked above. Future plans include also monitoring the NIST WWVB radio time signal from Fort Collins, Colorado, for an extra time dilation comparison.
We’ve featured innumerable clocks over the years here at Hackaday, but among them have been a few based upon atomic standards. More than one has been used as a lab reference standard, but most similar to this build is [Max Carters] experiments to check the accuracy of an atomic standard, also using the WWVB transmissions.