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77 lines
2.4 KiB
ReStructuredText
77 lines
2.4 KiB
ReStructuredText
PCF8574 I/O Expander
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====================
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.. seo::
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:description: Instructions for setting up PCF8574 digital port expanders in ESPHome.
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:image: pcf8574.jpg
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The PCF8574 component allows you to use PCF8574 or PCF8575 I/O expanders
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(`datasheet <http://www.ti.com/lit/ds/symlink/pcf8574.pdf>`__,
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`SparkFun`_) in ESPHome. It uses :ref:`I²C Bus <i2c>` for communication.
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Once configured, you can use any of the 8 pins (PCF8574) or 16 pins (PCF8575) as
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pins for your projects. Within ESPHome they emulate a real internal GPIO pin
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and can therefore be used with many of ESPHome's components such as the GPIO
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binary sensor or GPIO switch.
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Any option accepting a :ref:`Pin Schema <config-pin_schema>` can theoretically be used, but some more
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complicated components that do communication through this I/O expander will
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not work.
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.. figure:: images/pcf8574-full.jpg
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:align: center
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:width: 80.0%
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PCF8574 I/O Expander.
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.. _SparkFun: https://www.sparkfun.com/products/retired/8130
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.. code-block:: yaml
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# Example configuration entry
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pcf8574:
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- id: 'pcf8574_hub'
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address: 0x21
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pcf8575: false
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# Individual outputs
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switch:
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- platform: gpio
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name: "PCF8574 Pin #0"
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pin:
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pcf8574: pcf8574_hub
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# Use pin number 0
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number: 0
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# One of INPUT or OUTPUT
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mode: OUTPUT
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inverted: false
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Configuration variables:
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************************
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- **id** (**Required**, :ref:`config-id`): The id to use for this PCF8574 component.
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- **address** (*Optional*, int): The I²C address of the driver.
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Defaults to ``0x21``.
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- **pcf8575** (*Optional*, boolean): Whether this is a 16-pin PCF8575. Defaults to ``false``.
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Pin configuration variables:
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****************************
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- **pcf8574** (**Required**, :ref:`config-id`): The id of the PCF8574 component of the pin.
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- **number** (**Required**, integer): The pin number.
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- **inverted** (*Optional*, boolean): If all read and written values
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should be treated as inverted. Defaults to ``false``.
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- **mode** (*Optional*, string): A pin mode to set for the pin at. One of ``INPUT`` or ``OUTPUT``.
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See Also
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--------
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- :ref:`i2c`
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- :doc:`switch/gpio`
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- :doc:`binary_sensor/gpio`
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- `PCF8574 Arduino Library <https://github.com/skywodd/pcf8574_arduino_library>`__ by `Fabien Batteix <https://github.com/skywodd>`__
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- :apiref:`pcf8574/pcf8574.h`
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- :ghedit:`Edit`
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