Decipher 4x6 keyboard with 8 pins

[sergioarduino]

Hi Class,

I left 8 digital pins reserved on a Nodemcu 1.0 12E to connect a keyboard for a weighing scale that I am adding more functions to. When I looked at her keyboard more closely I noticed that it has 24 keys and 8 pins.

Of course, this doesn't make 4x4 = 16 keys.

I looked at the board with the keys and came across some 20K and 680r resistors and a screen print containing WGV12345 in the identification of the 8 pins.

The two photos are the same. Each with its own quality:

Can anyone help? By any luck, has anyone come across this type of keyboard? What would the code be like to use these keys on an esp8266 nodemcu 1.0 12E?

What code snippet could I try here?

Grateful. Good week.

[Railroader]

A 4 by 6 key keyboard can be handled by 2 + 3 I/O pins and 2 control pins using external circuitry. Else 10 pins would be needed.
Else drop some keys and use 4 by 4 keys.

[Railroader]

@sergioarduino

What code snippet could I try

Most likely, the one You create Yourself.

[Railroader]

@sergioarduino

I noticed that it has 24 keys and 8 pins.

Schematics please.

[sergioarduino]

My second option, which is becoming the first option, is to build another board and then put the keys in a 4x4 matrix format. But I found this here:

4x6 Button Matrix keypad.h wrong buttons

Hi fellow Arduino'ers, i build with my arduino micro an 4x6 Buttonmatrix for a Game. I can't access the first button (Doesn't match with any Pin setup). Buttons two to seven are working perfectly. But the the problem appears. If i press 8 the Controller output is 8 -> 9 -> 10 -> 11 -> 8 -> 9 -> 10 -> 11. If i press any other button it is the same result. The same behavior is for the buttons 14 - 17. The Buttons 12, 13 and 18 are working. [2021-12-07 21_05_40-arduino.drawio - diagrams.net] …

However, even so, on my board, in the photo, the key circuit is different.

I'll wait a bit to see if anyone has come across a keyboard like this and might want to help.

.

[sergioarduino]

I tried to draw the key diagram using a multimeter:

But I think I'm really going to make a new board with just the keys that I'm going to use. This keyboard contains resistors and so I think it uses voltage range and ADC input to distinguish certain keys. It's a complexity that my intention doesn't need at this moment. That's why I'm closing this topic.

[TomGeorge]

Hi,
Where did you get the board?

Can you please post a link to the PCB?

Thanks.. Tom...

[TomGeorge]

@sergioarduino

I tried to draw the key diagram using a multimeter:

Where are the wires that go to the WGV12345 connections?

Thanks.. Tom..

[sergioarduino]

@TomGeorge

Thanks

It's just a simple heavy scale as reported in post#1. I already resolved it here. I placed the keys in 4x4 format in a new layout on another plaque I made here. Good week.