kopia lustrzana https://github.com/micropython/micropython
209 wiersze
5.3 KiB
ReStructuredText
209 wiersze
5.3 KiB
ReStructuredText
class Pin --- control I/O pins
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==============================
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A pin is the basic object to control I/O pins. It has methods to set
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the mode of the pin (input, output, etc) and methods to get and set the
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digital logic level. For analog control of a pin, see the ADC class.
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Usage Model:
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All Board Pins are predefined as pyb.Pin.board.Name ::
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x1_pin = pyb.Pin.board.X1
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g = pyb.Pin(pyb.Pin.board.X1, pyb.Pin.IN)
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CPU pins which correspond to the board pins are available
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as ``pyb.cpu.Name``. For the CPU pins, the names are the port letter
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followed by the pin number. On the PYBv1.0, ``pyb.Pin.board.X1`` and
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``pyb.Pin.cpu.B6`` are the same pin.
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You can also use strings::
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g = pyb.Pin('X1', pyb.Pin.OUT_PP)
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Users can add their own names::
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MyMapperDict = { 'LeftMotorDir' : pyb.Pin.cpu.C12 }
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pyb.Pin.dict(MyMapperDict)
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g = pyb.Pin("LeftMotorDir", pyb.Pin.OUT_OD)
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and can query mappings ::
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pin = pyb.Pin("LeftMotorDir")
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Users can also add their own mapping function::
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def MyMapper(pin_name):
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if pin_name == "LeftMotorDir":
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return pyb.Pin.cpu.A0
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pyb.Pin.mapper(MyMapper)
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So, if you were to call: ``pyb.Pin("LeftMotorDir", pyb.Pin.OUT_PP)``
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then ``"LeftMotorDir"`` is passed directly to the mapper function.
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To summarise, the following order determines how things get mapped into
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an ordinal pin number:
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1. Directly specify a pin object
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2. User supplied mapping function
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3. User supplied mapping (object must be usable as a dictionary key)
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4. Supply a string which matches a board pin
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5. Supply a string which matches a CPU port/pin
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You can set ``pyb.Pin.debug(True)`` to get some debug information about
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how a particular object gets mapped to a pin.
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Constructors
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------------
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.. class:: pyb.Pin(id, ...)
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Create a new Pin object associated with the id. If additional arguments are given,
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they are used to initialise the pin. See ``init``.
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Class methods
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-------------
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.. method:: Pin.af_list()
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Returns an array of alternate functions available for this pin.
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.. method:: Pin.debug([state])
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Get or set the debugging state (``True`` or ``False`` for on or off).
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.. method:: Pin.dict([dict])
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Get or set the pin mapper dictionary.
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.. method:: Pin.mapper([fun])
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Get or set the pin mapper function.
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Methods
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-------
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.. method:: pin.__str__()
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Return a string describing the pin object.
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.. method:: pin.af()
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Returns the currently configured alternate-function of the pin. The
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integer returned will match one of the allowed constants for the af
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argument to the init function.
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.. method:: pin.gpio()
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Returns the base address of the GPIO block associated with this pin.
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.. method:: pin.high()
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Set the pin to a high logic level.
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.. method:: pin.init(mode, pull=Pin.PULL_NONE, af=-1)
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Initialise the pin:
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- ``mode`` can be one of:
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- ``Pin.IN`` - configure the pin for input;
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- ``Pin.OUT_PP`` - configure the pin for output, with push-pull control;
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- ``Pin.OUT_OD`` - configure the pin for output, with open-drain control;
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- ``Pin.AF_PP`` - configure the pin for alternate function, pull-pull;
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- ``Pin.AF_OD`` - configure the pin for alternate function, open-drain;
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- ``Pin.ANALOG`` - configure the pin for analog.
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- ``pull`` can be one of:
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- ``Pin.PULL_NONE`` - no pull up or down resistors;
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- ``Pin.PULL_UP`` - enable the pull-up resistor;
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- ``Pin.PULL_DOWN`` - enable the pull-down resistor.
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- when mode is Pin.AF_PP or Pin.AF_OD, then af can be the index or name
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of one of the alternate functions associated with a pin.
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Returns: ``None``.
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.. method:: pin.low()
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Set the pin to a low logic level.
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.. method:: pin.mode()
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Returns the currently configured mode of the pin. The integer returned
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will match one of the allowed constants for the mode argument to the init
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function.
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.. method:: pin.name()
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Get the pin name.
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.. method:: pin.names()
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Returns the cpu and board names for this pin.
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.. method:: pin.pin()
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Get the pin number.
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.. method:: pin.port()
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Get the pin port.
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.. method:: pin.pull()
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Returns the currently configured pull of the pin. The integer returned
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will match one of the allowed constants for the pull argument to the init
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function.
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.. method:: pin.value([value])
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Get or set the digital logic level of the pin:
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- With no argument, return 0 or 1 depending on the logic level of the pin.
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- With ``value`` given, set the logic level of the pin. ``value`` can be
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anything that converts to a boolean. If it converts to ``True``, the pin
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is set high, otherwise it is set low.
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Constants
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---------
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.. data:: Pin.AF_OD
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initialise the pin to alternate-function mode with an open-drain drive
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.. data:: Pin.AF_PP
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initialise the pin to alternate-function mode with a push-pull drive
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.. data:: Pin.ANALOG
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initialise the pin to analog mode
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.. data:: Pin.IN
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initialise the pin to input mode
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.. data:: Pin.OUT_OD
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initialise the pin to output mode with an open-drain drive
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.. data:: Pin.OUT_PP
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initialise the pin to output mode with a push-pull drive
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.. data:: Pin.PULL_DOWN
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enable the pull-down resistor on the pin
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.. data:: Pin.PULL_NONE
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don't enable any pull up or down resistors on the pin
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.. data:: Pin.PULL_UP
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enable the pull-up resistor on the pin
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