Maker Pro
Maker Pro

Seeking opinion on how to modify this selection knob.

Bujuk

Sep 13, 2022
2
Joined
Sep 13, 2022
Messages
2
hello guys, I'm working on a samsung front load washing machine. Which has an electronic selection knob. every time we switch on the machine, the selection will be "Cotton" as the default.

My question is, is there a way to modify/hack the selection knob so the default will be other than "cotton". For example if i modify the selection knob to "Delicate", the machine will automatically select "delicate" whenever i turn On the machine.

thanks in advance. thank you
 

Attachments

  • button.jpg
    button.jpg
    43.4 KB · Views: 4

Harald Kapp

Moderator
Moderator
Nov 17, 2011
12,770
Joined
Nov 17, 2011
Messages
12,770
Short answer:
Most likely no.

Long answer:
The knob itself is probably a rotary encoder which gives only information about changes in position, but no absolute position.
For the software to have a "starting point" upon turning on the machine, the default state is most likely programmed into the software. To change the default state will require a re-programming of the software or the code defining the default state somewhere in non-volatile memory.
Not impossible with a lot of hard re-engineering work - impossible otherwise.
There may (or may not) be a software tool that the manufacturer can use to program the default state. I doubt such a tool, if it exists, is freely available.
 

Bujuk

Sep 13, 2022
2
Joined
Sep 13, 2022
Messages
2
thank you Harald for the clarification. I really hope i can do something about the knob. obviously it is not an easy task. I ll look other options. thanks
 

crutschow

May 7, 2021
520
Joined
May 7, 2021
Messages
520
As Harold noted, the initial selection on power-up is likely in the controller software.
Nothing you can do to the knob will affect that.

The only possibility I see is to determine what the signal output is from the knob to the controller to go from Cotton to Delicate, and add a circuit to generate that signal when (or shortly after) power is applied.
The circuit would then be controlled by the knob for any further selections.
Commonly such a control knob generates a 2-phase quadrature digital (on-off) signal using two wires plus common (example below).
This is decoded by the controller to determine which direction the knob moves, and by how much.

1663171018556.png
 
Last edited:

crutschow

May 7, 2021
520
Joined
May 7, 2021
Messages
520
I just realized you probably want the circuit to remember the last setting and go to that, which means you would need to detect and remember the last of the ten selection lights that was lit before power was removed, which adds another level of complexity.
An added microcontroller, programmed to do all that, would likely be the easiest way.
Have you done any programming?
 
Top