TCA9555 I/O Expander
====================

.. seo::
    :description: Instructions for setting up TCA9555 digital port expanders in ESPHome.

The TCA9555 component allows you to use TCA955 I/O expanders
(`datasheet <https://www.ti.com/lit/ds/symlink/tca9555.pdf>`) in ESPHome. It uses :ref:`I²C Bus <i2c>` for communication.

Once configured, you can use any of the 16 pins (TCA9555) as
pins for your projects. Within ESPHome they emulate a real internal GPIO pin
and can therefore be used with many of ESPHome's components such as the GPIO
binary sensor or GPIO switch.

Any option accepting a :ref:`Pin Schema <config-pin_schema>` can theoretically be used, but some more
complicated components that do communication through this I/O expander will
not work.

.. code-block:: yaml

    # Example configuration entry
    tca9555:
      - id: 'TCA9555_hub'

    # Individual outputs
    switch:
      - platform: gpio
        name: "TCA9555 Pin #0"
        pin:
          tca9555: tca9555_hub
          # Use pin number 0
          number: 0

Configuration variables:
************************

- **id** (**Required**, :ref:`config-id`): The id to use for this TCA9555 component.
- **address** (*Optional*, int): The I²C address of the driver.
  Defaults to ``0x21``.

Pin configuration variables:
****************************

- **TCA9555** (**Required**, :ref:`config-id`): The id of the TCA9555 component of the pin.
- **number** (**Required**, int): The pin number.
- **inverted** (*Optional*, boolean): If all read and written values
  should be treated as inverted. Defaults to ``false``.
- **mode** (*Optional*, string): A pin mode to set for the pin at. One of ``INPUT`` or ``OUTPUT``.


See Also
--------

- :ref:`i2c`
- :doc:`switch/gpio`
- :doc:`binary_sensor/gpio`
- `TCA9555 Arduino Library <https://github.com/RobTillaart/TCA9555>`__ by `Rob Tillaart <https://github.com/RobTillaart>`__
- :apiref:`TCA9555/TCA9555.h`
- :ghedit:`Edit`