ATC Clock Sync
Clock sync and calibration for the Xiaomi LYWSD03MMC with pvvx custom firmware (Web Bluetooth). Calibration data is read from the device; the browser only stores a cookie with the name of the last connected device.
Device
disconnected
Times
PC (local time)–
Device (last reading)–
Offset vs PC local time–
Last time set (stored in device)–
Calibration
Time since last set–
Accumulated error–
Residual drift (with active trim)–
Active hardware trim (cmd 0x24)–
Estimated crystal error–
Measurement uncertainty–
Daylight saving time
Current offset–
Offset at last time set–
Next change–
Options (this session only)
The device itself keeps the time of the last set (in RAM: lost if the battery is removed) and the clock trim (in flash). From these two values the page derives the accumulated error and the drift. To avoid losing the measurement reference, "Sync" does not reset the time while the interval is still short and the error is small; "Force set time" always writes it. Whenever the hardware trim is updated, the time is always reset right afterwards.