PCA9554 I/O Expander

The PCA9554 component allows you to use PCA9554, PCA9554A or PCA9536 I/O expanders in ESPHome. It uses I²C Bus for communication.


PCA9554A I/O Expander chip

Once configured, you can use any of the 8 pins (PCA9554, PCA9554A) or 4 pins (PCA9536) 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.


The 7 bit I²C device address ranges are:

  • PCA9554: 0x20 to 0x27

  • PCA9554A: 0x38 to 0x3F

  • PCA9536: 0x41

For the PCA9554 and PCA9554A, the actual choice of the I²C device address depends on state of the 3 address pins. Please refer to the individual datasheets linked at the bottom of the page for further details to set the address.

Up to eight PCA9554 and an additional eight PCA9554A devices can reside on the same I²C bus. Please note that only one PCA9536 device is allowed per I²C bus due to its fixed address.

The PCA9554 and PCA9554A provide 8 bits of GPIO’s (pin numbers 0-7).

The PCA9536 provides 4 bits of GPIO’s (pin numbers 0-3).

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
  - id: 'pca9554a_device'
    address: 0x38

# Individual outputs
  - platform: gpio
    name: "PCF9554A Pin #0"
      pca9554: pcf9554a_device
      # Use pin number 0
      number: 0
      # One of INPUT or OUTPUT
        output: true
      inverted: false

Configuration variables:

  • id (Required, ID): The id to use for this pca9554 component.

  • address (Optional, int): The I²C address of the driver. Defaults to 0x20.

Pin configuration variables:

  • pca9554 (Required, ID): The id of the pca9554 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