UPDATE - ESP8266 nEXT Evo Board - 4x4 Matrix Keyboard - P4

[TJ232]

Hello,

This new board is just a simple ESP8266 Board with USB + Extension Bus (nEXT) and is the result of looking for a smaller and somehow a more flexibile hardware configuration than the CBDB Evolution DevBoard.

This is how is looking the PCB for it:


and the finished Board:


This is the board that was also used for the long run battery tests posted on ESP8266 forum:
Ultra low power application schematic: RFC
In this case on top of it was added the RTC/Li-Ion battery charger nEXT module.

For more details about, please see related articles:

CBDB nEXT Evo Board - General presentation and schematics
CBDB nEXT Evo - Firmware upload and first run tests

[TJ232]

And the first Extension board, if you didn't seen it yet, this is AN1, the ANALOG ADC/DAC + I/O Board for CBDB nEXT EVO: http://www.esp8266-projects.com/2015/12/p3-esp8266-next-evo-analog-extension.html.
Off course can be directly used with any other MCU, Arduino, etc as long as it has a I2C bus and 3V logic.

 Basic default functions of the CBDB nEXT AN1 Extension Board:

• INPUT :    0-40V Autorange Analog frontend / 18 Bit ADC
• OUTPUT : 4x12 BIT DAC
• TEMPERATURE : I2C Temperature sensor, standard or high precision options
• I/O:  8 Bit I/O Expansion Port

[TJ232]

And a Graphical Display option for it

My first option for a Alphanumeric Display still remain the ST7032i LCD one, but as I was looking also for a Graphical Display option, I found this SSD1306 OLED as a easy to use one with the CBDB nEXT EVO Board.

Youtube Video :
https://youtu.be/4DzMogqOHWc

 
Original article about http://www.esp8266-projects.com/2015/12/mailbag-ssd1306-oled-display-for.html

[TJ232]

The SAGA Continues: Part 2 of the ESP8266 nEXT EVO Analog Extension Board (AN1)

  In this part we will talk a bit about the nEXT Bus I²C protocol  and we will start also a longer, multi-part discussion about testing procedures and software programming for the AN1 Board devices and functions (I/O Expansion port, Temperature, ADC, DAC, Voltage measurements,etc.




Any related comments, suggestions, ideas, are warmly welcomed




Thank you,
TJ.

[TJ232]

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

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.



 

[TJ232]

 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: