Hello everyone, I currently want to control my washing machine using a microcontroller. I found that the board is powered by a connector labeled "CN3" based on this picture. This connector is connected to the logic board powered through a 220VAC, and then passed through a transformer. I unfortunately can't find the datasheet of the transformer This should be the part, but I can't download it.

I believe that the display board is the one who will send commands to control board. I'm thinking of probing using USB to TTL, or using a logic analyzer to understand the commands sent. However I'm not sure which one is the VCC, GND, Tx, or Rx. By only looking at the board and without powering the board through a power plug (220VAC), is it possible for me to identify which one is the VCC and GND for CN3? And, How much voltage (3V3, 5V, 12V) and amps should I source to the board?


This is the image of the back side of the PCB






And this is the control board. I can't show the back side of the PCB because everything is being resin-ed to the plastic molding.

Thank you for your help.

 

is it way too obvious for some people just by looking at the wire color? should I just follow this cable color code I found randomly on the internet?

 

There is not any standard for a color code for digital logic connections. There is a standard for connections to both 9 position and 25 position connectors, and some others, but nothing for washer machines. There is indeed a standard for numbers versus colors, that is used for indicating component values, and also a telecom color code.
But the cable shown would not reflect conformance to any standard that I am aware of as far as logic connections.
There should be, someplace dry inside the washer machine, an electrical circuit drawing, along with a lot of useful information, that will describe the connections and also the functionality. If you still have possession of the machine body.

And why do you want to machine with a microcontroller???

 

I believe that the display board is the one who will send commands to control board.

More likely the other way round. The control MCU will monitor the states of the various switches, transducers and buttons and send commands to the display, motor, sounder and valves.
How do you propose adding your own MCU so that it doesn't conflict with the existing one?

 

There should be, someplace dry inside the washer machine, an electrical circuit drawing, along with a lot of useful information, that will describe the connections and also the functionality. If you still have possession of the machine body.

And why do you want to machine with a microcontroller???

More likely the other way round. The control MCU will monitor the states of the various switches, transducers and buttons and send commands to the display, motor, sounder and valves.
How do you propose adding your own MCU so that it doesn't conflict with the existing one?

Unfortunately no, seems like they are not sharing any information regarding the electrical circuit drawing.

My idea is that the display board and the control board probably will communicate through serial communication, In my mind, the system should be sending a signal from the display board (tx), to the control board (rx). I want to remove the display board, use the existing harness, and connect it to a microcontroller to send the same signal/command the display board send to the control board, so that I can control my washing machine from afar by creating an API server or something similar.

My power cable has just arrived, meaning that I have no more reason to power the board without having to power the system.

This is what i found from putting multimeter to the female connector (from the control board):

say that the connector looks like below, and we number it also like below:

1 to 3 = 5V stable
2 to 3 = 2.7V ~ 3.7V
4 to 3 = 18.32V stable
5 to 3 = 5V stable
6 to 3 = 0V (continuity test no sound)
1 to 5 = 0V (continuity test no sound)

I assume that number 2 is a signal coming from the control board.
Connecting to all socket except number 4 (since it's 18V) to my logic analyzer shows that it has no clock used.

My current assumption that it is communicating using UART. I'm currently testing baud rates, number of bits, etc, but still have no luck.

 

What is the intended purpose for adding another control to the wash machine?? The actual control process is rather complex.
And if it is a very modern front load machine, there are a number of additional considerations.
If the intention is to replace a failed controller, it is quite possible that a system reset can solve the problem. I did exactly that for a client several years ago. Her machine had stopped working and a totally incompetent "factory serviceman" had quoted many hundreds of dollars to replace the defective control board.

I studied the instructions sheet and did a reset command , and then unplugged it for a minute. When I plugged it back in the machine functioned correctly. And it has continued to perform correctly for several years since.

So it might be that only a reset is in order.

BUT if the intention is to replace the control, I suggest that it will be vastly simpler to totally replace the power controls instead of attempting to use the existing control system.

 

What is the intended purpose for adding another control to the wash machine?? The actual control process is rather complex.
And if it is a very modern front load machine, there are a number of additional considerations.
If the intention is to replace a failed controller, it is quite possible that a system reset can solve the problem. I did exactly that for a client several years ago. Her machine had stopped working and a totally incompetent "factory serviceman" had quoted many hundreds of dollars to replace the defective control board.

I studied the instructions sheet and did a reset command , and then unplugged it for a minute. When I plugged it back in the machine functioned correctly. And it has continued to perform correctly for several years since.

So it might be that only a reset is in order.

BUT if the intention is to replace the control, I suggest that it will be vastly simpler to totally replace the power controls instead of attempting to use the existing control system.

The intention is purely so that i can control the washing machine without touching any button from the display board. The washing machine has several washing program (3 or 4 to be exact), I want to have a full control (normal wash, delicate, etc.) from my phone to run the machine. The reason why I don't try to control the power source is because I don't have control for which program to run. I know this is probably a bit overkill, but hey I'm probably learning something by doing this

 

REmote control of the washer machine, other than delivering a "start" command, seems like a dive into disaster.
Every part of the control scheme is private knowledge that is not likely to be available. And the serial communication is not likely to be in any normal format.
What you have is an embedded control system, and it has been developed for the one application. And certainly the communications format is proprietary.

 

REmote control of the washer machine, other than delivering a "start" command, seems like a dive into disaster.
Every part of the control scheme is private knowledge that is not likely to be available. And the serial communication is not likely to be in any normal format.
What you have is an embedded control system, and it has been developed for the one application. And certainly the communications format is proprietary.

it's nothing but a project that i want to try. so, yeah probably I'll timebox it for several weeks and see if I can get anything from it. Else, I'll probably try another option

 

Since you need to be at the machine in order to load it up with clothes, detergent etc, what's so difficult about turning a knob and/or pressing a machine button by hand?

 

Since you need to be at the machine in order to load it up with clothes, detergent etc, what's so difficult about turning a knob and/or pressing a machine button by hand?

it is not good to leave your washed laundry inside the washing machine for too long. say that I wash my laundry at 8 AM before work, then I got back at 6 PM, the laundry will smell awful. So, it would be great if I can wash my laundry when I'm on my way back home, and my laundry is done when I'm back from work

 

All you need to do is use a reed relay connected in parallel to each button you wish to control, and control them from an ESP32 or equivalent.

 

All you need to do is use a reed relay connected in parallel to each button you wish to control, and control them from an ESP32 or equivalent.

Yes this is exactly what was my idea previously, i made a thread about this also. However i can't know the current state of the system (did it ran into an error, is it still washing). So, I want to go a bit deeper.