.. include:: defs.hrst

AnalogIn
========

An analog (ie. continuous) input unit that returns values between 0 and 1 (ie. 0% and 100%).

The unit is assigned to a specific ``pin`` on the board.

The ``mode`` specifies the behavior of the component attached to the pin:

- in ``DIRECT`` mode (default) the value is expressed as a percentage of the reference voltage (Vref, typically 5V)
- in ``INVERTED`` mode the value is inverted (ie. 0V corresponds to 100% while 2.5V corresponds to 50%).

.. warning::

   If the analog input pin is **not connected** to anything, the value returned by ``get()`` will fluctuate
   based on a number of factors (e.g. the values of the other analog inputs, how close your hand is to
   the board, etc.).

|Example|
---------

Control an LED using a potentiometer.

.. code-block:: c++

   #include <Plaquette.h>

   AnalogIn potentiometer(A0);

   AnalogOut led(9);

   SineWave oscillator;

   void begin() {}

   void step() {
     // The analog input controls the frequency of the LED's oscillation.
     oscillator.frequency(potentiometer.mapTo(2.0, 10.0));
     oscillator >> led;
   }


|Reference|
-----------

.. doxygenclass:: AnalogIn
   :project: Plaquette
   :members:

|SeeAlso|
---------
- :doc:`AnalogOut`
- :doc:`DigitalIn`
