Pcf8574-Gpio-Extender-Lib 关于库 Pcf8574-Gpio-Extender-Lib is for supporing multiple Pcf8574 boards together in chain with less complexcity of the programming mex we can connect 8 Pcf8574 together in chain which will give extra 64 pins for operations this api support a simple interface where we can controll 1-64 pins by its sequence number respected to their sequence in the chain pin number will s