pca9674a — I2C Expander Driver

8-bit I/O expander.

class PCA9674A – 8-bit I/O expander

class pca9674a.PCA9674A(bus: machine.I2C, irq_pin: str, address: int = 63, callback: Callable | None = None)

Creates an interface to the I/O expander.

• bus is the machine.I2C bus the expander is connected to.

• irq_pin is the pin label connected to the expander’s IRQ output.

• address is the I2C address of the expander.

• callback is invoked on the falling edge of irq_pin when any pin state changes.

write(value: int) → None

Writes the 8-bit value to the I/O expander pins.

read() → int

Returns the 8-bit value of the I/O expander pins.

reset() → None

Resets and re-initializes the I/O expander, and re-attaches the IRQ callback if one was provided.