PCF8574 I/O Expander¶
The PCF8574 component allows you to use PCF8574 or PCF8575 I/O expanders (datasheet, SparkFun) in ESPHome. It uses I²C Bus for communication.
Once configured, you can use any of the 8 pins (PCF8574) or 16 pins (PCF8575) 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 Pin Schema can theoretically be used, but some more complicated components that do communication through this I/O expander will not work.
# Example configuration entry pcf8574: - id: 'pcf8574_hub' address: 0x21 pcf8575: false # Individual outputs switch: - platform: gpio name: "PCF8574 Pin #0" pin: pcf8574: pcf8574_hub # Use pin number 0 number: 0 # One of INPUT or OUTPUT mode: output: true inverted: false
id (Required, ID): The id to use for this PCF8574 component.
address (Optional, int): The I²C address of the driver. Defaults to
pcf8575 (Optional, boolean): Whether this is a 16-pin PCF8575. Defaults to
If you use PCF8575, pin numbers are from 0 to 15, not 0 to 7 and 10 to 17 as datasheet states!
Pin configuration variables:¶
pcf8574 (Required, ID): The id of the PCF8574 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
mode (Optional, string): A pin mode to set for the pin at. One of