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d8e0320485
The WiPy machine.Timer class is very different to the esp8266 and esp32 implementations which are better candidates for a general Timer class. By moving the WiPy Timer docs to a completely separate file, under a new name machine.TimerWiPy, it gives a clean slate to define and write the docs for a better, general machine.Timer class. This is with the aim of eventually providing documentation that does not have conditional parts to it, conditional on the port. While the new docs are being defined it makes sense to keep the WiPy docs, since they describe its behaviour. Once the new Timer behaviour is defined the WiPy code can be changed to match it, and then the TimerWiPy docs would be removed.
65 lines
1.9 KiB
ReStructuredText
65 lines
1.9 KiB
ReStructuredText
.. currentmodule:: machine
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.. _machine.Timer:
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class Timer -- control hardware timers
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======================================
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Hardware timers deal with timing of periods and events. Timers are perhaps
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the most flexible and heterogeneous kind of hardware in MCUs and SoCs,
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differently greatly from a model to a model. MicroPython's Timer class
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defines a baseline operation of executing a callback with a given period
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(or once after some delay), and allow specific boards to define more
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non-standard behavior (which thus won't be portable to other boards).
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See discussion of :ref:`important constraints <machine_callbacks>` on
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Timer callbacks.
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.. note::
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Memory can't be allocated inside irq handlers (an interrupt) and so
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exceptions raised within a handler don't give much information. See
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:func:`micropython.alloc_emergency_exception_buf` for how to get around this
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limitation.
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If you are using a WiPy board please refer to :ref:`machine.TimerWiPy <machine.TimerWiPy>`
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instead of this class.
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Constructors
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------------
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.. class:: Timer(id, ...)
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Construct a new timer object of the given id. Id of -1 constructs a
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virtual timer (if supported by a board).
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Methods
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-------
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.. method:: Timer.init(\*, mode=Timer.PERIODIC, period=-1, callback=None)
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Initialise the timer. Example::
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tim.init(period=100) # periodic with 100ms period
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tim.init(mode=Timer.ONE_SHOT, period=1000) # one shot firing after 1000ms
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Keyword arguments:
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- ``mode`` can be one of:
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- ``Timer.ONE_SHOT`` - The timer runs once until the configured
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period of the channel expires.
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- ``Timer.PERIODIC`` - The timer runs periodically at the configured
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frequency of the channel.
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.. method:: Timer.deinit()
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Deinitialises the timer. Stops the timer, and disables the timer peripheral.
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Constants
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---------
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.. data:: Timer.ONE_SHOT
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Timer.PERIODIC
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Timer operating mode.
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