:mod:`alarm.pin`
================

.. py:module:: alarm.pin





.. py:class:: PinAlarm(pin: microcontroller.Pin, value: bool, edge: bool = False, pull: bool = False)

   Trigger an alarm when a pin changes state.

   Create an alarm triggered by a `microcontroller.Pin` level. The alarm is not active
   until it is passed to an `alarm`-enabling function, such as `alarm.light_sleep_until_alarms()` or
   `alarm.exit_and_deep_sleep_until_alarms()`.

   :param microcontroller.Pin pin: The pin to monitor. On some ports, the choice of pin
     may be limited due to hardware restrictions, particularly for deep-sleep alarms.
   :param bool value: When active, trigger when the pin value is high (``True``) or low (``False``).
     On some ports, multiple `PinAlarm` objects may need to have coordinated values
     for deep-sleep alarms.
   :param bool edge: If ``True``, trigger only when there is a transition to the specified
     value of ``value``. If ``True``, if the alarm becomes active when the pin value already
     matches ``value``, the alarm is not triggered: the pin must transition from ``not value``
     to ``value`` to trigger the alarm. On some ports, edge-triggering may not be available,
     particularly for deep-sleep alarms.
   :param bool pull: Enable a pull-up or pull-down which pulls the pin to the level opposite
     that of ``value``. For instance, if ``value`` is set to ``True``, setting ``pull``
     to ``True`` will enable a pull-down, to hold the pin low normally until an outside signal
     pulls it high.

   .. py:attribute:: pin
      :annotation: :microcontroller.Pin

      The trigger pin.


   .. py:attribute:: value
      :annotation: :bool

      The value on which to trigger.