The PCF8574 IO Expansion Module is a remote 8-bit I/O expander for I2C-bus.
Up to 8 PCF8574 IO Expansion Board can be connected to the I2C-bus, providing up to 64 I/O ports.
The PCF8574 IO Expansion Board features I2C female header sockets on one side, and I2C male header pins connector on the opposite side. This allows the I2C connection to be made using either male pins or female sockets. This module also supports I2C cascading, allowing the use of multi module connected to the I2C bus at the same time by connecting one module to the other.