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By virtue of its name, the pyb module would only be available on a pyboard and so does not need to have conditional "only" directives throughout its documentation. These conditionals were added mostly incfcf47c064in the initial development of the cc3200 port, which had the pyb module before it switched to the machine module. And wipy only conditionals were removed from the pyb module documentation in4542643025, so there's no need to retain any more conditionals.
79 lines
2.2 KiB
ReStructuredText
79 lines
2.2 KiB
ReStructuredText
.. currentmodule:: pyb
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.. _pyb.RTC:
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class RTC -- real time clock
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============================
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The RTC is and independent clock that keeps track of the date
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and time.
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Example usage::
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rtc = pyb.RTC()
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rtc.datetime((2014, 5, 1, 4, 13, 0, 0, 0))
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print(rtc.datetime())
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Constructors
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------------
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.. class:: pyb.RTC()
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Create an RTC object.
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Methods
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-------
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.. method:: RTC.datetime([datetimetuple])
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Get or set the date and time of the RTC.
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With no arguments, this method returns an 8-tuple with the current
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date and time. With 1 argument (being an 8-tuple) it sets the date
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and time (and ``subseconds`` is reset to 255).
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The 8-tuple has the following format:
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(year, month, day, weekday, hours, minutes, seconds, subseconds)
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``weekday`` is 1-7 for Monday through Sunday.
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``subseconds`` counts down from 255 to 0
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.. method:: RTC.wakeup(timeout, callback=None)
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Set the RTC wakeup timer to trigger repeatedly at every ``timeout``
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milliseconds. This trigger can wake the pyboard from both the sleep
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states: :meth:`pyb.stop` and :meth:`pyb.standby`.
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If ``timeout`` is ``None`` then the wakeup timer is disabled.
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If ``callback`` is given then it is executed at every trigger of the
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wakeup timer. ``callback`` must take exactly one argument.
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.. method:: RTC.info()
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Get information about the startup time and reset source.
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- The lower 0xffff are the number of milliseconds the RTC took to
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start up.
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- Bit 0x10000 is set if a power-on reset occurred.
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- Bit 0x20000 is set if an external reset occurred
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.. method:: RTC.calibration(cal)
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Get or set RTC calibration.
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With no arguments, ``calibration()`` returns the current calibration
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value, which is an integer in the range [-511 : 512]. With one
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argument it sets the RTC calibration.
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The RTC Smooth Calibration mechanism adjusts the RTC clock rate by
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adding or subtracting the given number of ticks from the 32768 Hz
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clock over a 32 second period (corresponding to 2^20 clock ticks.)
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Each tick added will speed up the clock by 1 part in 2^20, or 0.954
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ppm; likewise the RTC clock it slowed by negative values. The
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usable calibration range is:
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(-511 * 0.954) ~= -487.5 ppm up to (512 * 0.954) ~= 488.5 ppm
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