Class RTC – Real Time Clock¶
RTC is an independent clock that track date and time.
Example:
import machine
from machine import RTC
rtc = machine.RTC()
rtc.init((2018, 11, 21, 3, 9, 0, 0, 0))
print(rtc.datetime())
Method¶
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RTC.init([datetimetuple])¶
Initialize RTC. The date and time are 8 tuples of the form：
( year,month,day,weekday,hour,minute,second,microsecond )
Attention
weekday: Monday to Sunday correspond to [0-6] instead of [1-7]- The value in the millisecond is actually the value after the decimal point in seconds
-
RTC.datetime([datetimetuple])¶
When the time tuple is given, the RTC date and time are set, and if the parameter is not given, the current time tuple is returned. The 8-tuple format is the same as above.
>>> rtc.datetime()
(2018, 11, 18, 6, 12, 15, 8, 142409)
>>>
>>> rtc.datetime((2018, 11, 18, 6, 12, 15, 5, 607409))
(2018, 11, 18, 6, 12, 15, 8, 142409)
Although RTC can track the time and date for us, the accuracy of RTC has certain defects. Every 7: 45h there will be an error overflow of the second level, so it is recommended to perform time calibration every 7 hours.
Since the timer cannot perform timing work after a power failure, this will cause your device to enter the initial time before the next start-up January 1, 2000. So if we want to control the time accurately, we need to calibrate the time when we turn on.
Use ntptime module performs network timing calibration time.