Method to know that the RTC was initialized and has valid time/date

[IndianaTux]

If there a method to know that the RTC (on an M5 Core2 or M4 CoreInk) was initialized and does not need to be updated in a scenario where Internet (NTP) access is not available ?

Thanks.

[felmue]

Hello @IndianaTux

have a look at the PCF8563 datasheet chapter 8.4.1 Register VL_seconds. In addition to the seconds, register 0x02 also holds a bit (7), which gets set if the voltage dropped too much.

I don't see a ready made method / function to read this bit in the M5Core2 library on github, but it should be relatively easy to add.

Thanks
Felix

[IndianaTux]

@felmue Thanks for the pointer !