PCF8574; PCF8574A Remote 8-bit I/O expander for I2C-bus ...
1. General description The PCF8574/74A provides general-purpose remote I/O expansion via the two-wire bidirectional I2C-bus (serial clock (SCL), serial data (SDA)). The devices consist of eight quasi-bidirectional ports, 100 kHz I2C-bus interface, three hardware address inputs and interrupt output operating between 2.5 V and 6 V.
Lee mas