micropython: add micropython component

components/language/micropython/docs/library/machine.ADC.rst

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+.. currentmodule:: machine
+.. _machine.ADC:
+
+class ADC -- analog to digital conversion
+=========================================
+
+The ADC class provides an interface to analog-to-digital convertors, and
+represents a single endpoint that can sample a continuous voltage and
+convert it to a discretised value.
+
+For extra control over ADC sampling see :ref:`machine.ADCBlock <machine.ADCBlock>`.
+
+Example usage::
+
+   from machine import ADC
+
+   adc = ADC(pin)        # create an ADC object acting on a pin
+   val = adc.read_u16()  # read a raw analog value in the range 0-65535
+   val = adc.read_uv()   # read an analog value in microvolts
+
+Constructors
+------------
+
+.. class:: ADC(id, *, sample_ns, atten)
+
+   Access the ADC associated with a source identified by *id*.  This
+   *id* may be an integer (usually specifying a channel number), a
+   :ref:`Pin <machine.Pin>` object, or other value supported by the
+   underlying machine.
+
+   If additional keyword-arguments are given then they will configure
+   various aspects of the ADC.  If not given, these settings will take
+   previous or default values.  The settings are:
+
+     - *sample_ns* is the sampling time in nanoseconds.
+
+     - *atten* specifies the input attenuation.
+
+Methods
+-------
+
+.. method:: ADC.init(*, sample_ns, atten)
+
+   Apply the given settings to the ADC.  Only those arguments that are
+   specified will be changed.  See the ADC constructor above for what the
+   arguments are.
+
+.. method:: ADC.block()
+
+   Return the :ref:`ADCBlock <machine.ADCBlock>` instance associated with
+   this ADC object.
+
+   This method only exists if the port supports the
+   :ref:`ADCBlock <machine.ADCBlock>` class.
+
+.. method:: ADC.read_u16()
+
+   Take an analog reading and return an integer in the range 0-65535.
+   The return value represents the raw reading taken by the ADC, scaled
+   such that the minimum value is 0 and the maximum value is 65535.
+
+.. method:: ADC.read_uv()
+
+   Take an analog reading and return an integer value with units of
+   microvolts.  It is up to the particular port whether or not this value
+   is calibrated, and how calibration is done.