PCF8575 - 16 Bit I/O Port Expander - Driver implementation

Step-by-step Tutorial for programming the new ESP8266 PCF8575 - 16 Bit I/O Port Expander Board.

Part 1: Initalisation and Writing data on the 16Bit I/O Port.

Related Article : http://www.esp8266-projects.com/2016/06/p1-pcf8575-remote-16-bit-io-expander.html