Скачать или смотреть Easy DS3231 calibration: On-Demand Sync Clock (OSC)

Very short demo of the calibration process for DS3231, the RTC used in the “On-Demand Sync Clock (OSC)”

The distinctive feature of this clock is its effortless adjustment (sync and calibration): Simply press the push-button while an open network (Wi-Fi without password) is available, for instance, a smartphone hotspot.

The OSC is an open-source, DIY smart table clock that synchronizes with NTP (Network Time Protocol) servers on demand via a button press, automatically calibrates its RTC drift, and runs for months on battery power.
The DS3231 calibration becomes active 14 days after the previous sync, allowing a resolution finer than 1 ppm (part per million).

In this video, the clock had been running for almost 15 days since its last NTP sync, when the calibration was triggered. The NTP server provides the accurate time, which is then used to calculate the DS3231 drift. The “aging offset” register is adjusted automatically; in this case, the clock needed to slow down by 1 ppm (≈ 2.6 seconds per month).

More about this project: https://www.instructables.com/On-dema...