ESP8266 Community Forum

In this part we will continue exploring the ESP8266 nEXT Evo 8 Bit I/O Expansion Port based on the PCF8574 chip from NXP, testing procedures and software programming for the AN1 Board.

Part 3 of the ESP8266 nEXT EVO Analog Extension Board (AN1)

Part 4 of the ESP8266 nEXT EVO Analog Extension Board (AN1)

In this part we will continue talking about the ESP8266 nEXT Evo 8 Bit I/O Expansion Port based on the PCF8574 chip from NXP, testing procedures and software programming for the AN1 Board.

After testing the Output of the 8Bit I/O Port it's now time to test also the Input function.
So, what can be easier to use for such a processs than some pushbuttons for interaction? I was thinking about some sort of buttons interface and because I just have arround a small 4x4 Matrix Keyboard why not directly a keyboard interface, especially that I'm waiting to receive some very thin membrane ones to be used for some projects: