PCF8574 I/O Expander
====================

The PCF8574 component allows you to use PCF8574 and PCF8575 I/O port expanders with many of
esphomelib's components. With most components, you are able to specify GPIOOutputPin or
GPIOInputPin for internal pins. The PCF8574 component subclasses those types.

Example Usage
-------------

.. code-block:: cpp

    auto *pcf8574 = App.make_pcf8574_component(0x21);
    App.make_gpio_binary_sensor("PCF pin 0 sensor", pcf8574->make_input_pin(0, PCF8574_INPUT));
    App.make_gpio_binary_sensor("PCF pin 0 sensor", 0);
    App.make_gpio_switch("PCF pin 1 switch", pcf8574->make_output_pin(1));
    auto *out = App.make_gpio_output(pcf8574->make_output_pin(2));
    App.make_binary_light("PCF pin 2 light", out);

.. cpp:namespace:: esphomelib

See :cpp:func:`Application::make_pcf8574_component`.

API Reference
-------------

.. cpp:namespace:: nullptr

.. doxygenenum:: PCF8574GPIOMode

.. doxygenclass:: io::PCF8574Component
    :members:
    :protected-members:
    :undoc-members:

.. doxygenclass:: io::PCF8574GPIOInputPin
    :members:
    :protected-members:
    :undoc-members:

.. doxygenclass:: io::PCF8574GPIOOutputPin
    :members:
    :protected-members:
    :undoc-members: