Features:
Based on the I2C interface I / O expansion modules, use two I / O scalability eight I / O (up to 8 simultaneous use PCF8574, expanded to 64 I / O)
The most important feature:
1. Support two interface types access target board: Pin or row seat
2. Supports I2C bus cascade (by pin, row seat docking method, which can use multiple I2C modules)
Typical applications: for I / O resources were scarce MCU I / O expansion
The main resource: PCF8574, I2C interfaces, eight parallel