replace display on T12 soldering iron

[smile]

Hello, I would like to replace display on T12 chinese soldering iron.
The current display works by I2C 4 wires. Image attached.

OLED seems to be typical 30 wire.

I would like to use bigger display like this
https://www.ebay.com/itm/1-54-OLED-Display-Module-12864-LCD-Screen-SPI-Serial-Port-For-Arduino-Yellow/322785495290?hash=item4b2783c8fa%3Ag%3AFVgAAOSwcqBZyp~u&_sacat=0&_nkw=oled+screen+yellow&_from=R40&rt=nc&LH_TitleDesc=0%7C0

Now controller must match for it to work.

[JS]

Are you planning on touching up the firmware or just a drop in replacement? In any case you will need a i2c display, not a spi one.

  Then, for a drop in you need to match the pixel count, otherwhise the display will show whatever, and the controller chip which is likely to be the same, and later hope than both displays behaves the same.

JS

[smile]

Display will be "drop in" replacement.
I tried this 128x64px display

https://www.ebay.com/itm/0-96-I2C-IIC-Serial-128-64-OLED-LCD-Screen-LED-Display-Module-for-Arduino-au/183176374087?var=690453422388&hash=item2aa629a747%3Ag%3A69YAAOSwSlRa0BKt&_sacat=0&_nkw=oled+screen+yellow&_from=R40&rt=nc&LH_TitleDesc=0%7C0

And it does not work at all.

[JS]

Do both have the same amount of colours?

JS

[smile]

Both are 128x64px displays, both are I2C. original is 1.3" blue color, the one I tried is 0.96" white (Driver IC: SSD1306).
The T12 iron is https://www.aliexpress.com/store/product/STM32-2-1S-OLED-T12-Solder-Iron-Temperature-Controller-Welding-Tools-Electronic-Soldering-Wake-Sleep-Shock/1486111_32788912011.html?spm=2114.12010612.8148356.6.172111d7Rrg7JL

The only one with individual soldering tip temperature calibration feature. Nice font, too. They gave new 2018version but font is crap, and they even made power in small connector like big wires soldered directly to PCB was bad.

[Zimphire]

You can get a display and a whole newer controller for less than $20. I'd do that instead.

[JS]

You can get a display and a whole newer controller for less than $20. I'd do that instead.

I think he wants a bigger display, most soldering irons have a tini tiny display, mine does but it's fine for my eyes, I can read 0805 resistors markings bare eyed with some effort.

What you can do is to get a soldering iron with LED segment displays, not as much info on the display but you can see the temp in bug chunky numbers.

JS

[smile]

to my question "Why Can't you tell me driving IC for your screen so I can try find another color /size that would work?"
The KSGER Official Store replied that "our engineer donot allow me to tell that."

So much for support. Any way to solder new bigger screen to the PCB in the photo in hopes that it would work.
The screens seem to have same 30 wire flex cable. Doesn't they are standardized? The controller is on PCB or the screen itself?

[smile]

You can get a display and a whole newer controller for less than $20. I'd do that instead.

I think he wants a bigger display, most soldering irons have a tini tiny display, mine does but it's fine for my eyes, I can read 0805 resistors markings bare eyed with some effort.

What you can do is to get a soldering iron with LED segment displays, not as much info on the display but you can see the temp in bug chunky numbers.

JS

I can't use LED segment displays since I want to see info about soldering tip I currently use. I need to see that it is calibrated and a way to select them. This is not possible with 7 segment displays imho.

[JS]

Then you have a few options,
  One is start ordering displays and try to get one that works, the remaining could be used for other personal projects.
  Order a soldering iron with a bigger display already, I know most of them have tiny screens.
  Try to modify the code for yours to accept a different screen, I believe firmware for this STM32 soldering irons are on line but you would need to reverse engineer the controller board to be sure the µC and connections are the same for the firmware you get or modify the code so it fits. You could download the original firmware so you can go back if that doesn't work.
  Watch the data bus and try to make sense of the data to find a proper replacement.
  After reading the post again I see you are trying to go for a smaller display, I don't exactly understand why you are doing this, but couldn't the seller send a replacement display for you to mock around, you probably need to tell them your display isn't working but the iron does heat up and all that. If you have a second one you could even try to solder a 30 pin OLED directly to the PCB they had sent you, or reverse engineer the display PCB and make a new one for yours, it doesn't looks as simple as drop in but it seems like you are having trouble to find one.

JS

[stj]

you need the same resolution and the same controller.
ALSO, you need it set to the same i²c address - a lot of displays have a couple of pads on them to select between several addresses.

[JS]

you need the same resolution and the same controller.
ALSO, you need it set to the same i²c address - a lot of displays have a couple of pads on them to select between several addresses.

The adress, I forgot the adress...

You could check yours by looking at the controller part number, as said it will probably have a few options but looking at the PCB should tell.

JS

[smile]

you need the same resolution and the same controller.
ALSO, you need it set to the same i²c address - a lot of displays have a couple of pads on them to select between several addresses.

The adress, I forgot the adress...

You could check yours by looking at the controller part number, as said it will probably have a few options but looking at the PCB should tell.

The PCB photo is on my first post, I see nothing useful there.
I have only once LCD PCB. I could try ordering another and remove the screen but judging from Chinese reply there will be nothing there too. Without the address even with same pin count screen it will not work?

JS

[JS]

No, if the adress is not the same they won't be able to talk.

JS

[stj]

datasheets are your friend at this point.

[JS]

datasheets are your friend at this point.

He doesn't know what part the display has before ordering, at least not the exact one tp know the adress range it works on.

But even the chineese publications tells you the adress of the display, most of them. If the adress is close to yours, like 2 or 3 bits away there's a good chance to be useful for this.

JS

JS

[smile]

Update.

https://www.aliexpress.com/item/32788912011.html?spm=a2g0o.store_pc_groupList.8148356.2.3d2211d70K0Zgg

On KSGER T12 soldering station I tried to replace blue display with white.
The display works but characters are not correct they are distorted, go onto each other. etc.

How to fix?

Can I resolder the display module from white screen to blue would this work?

[smile]

I found to use SCK и SDA, pull up resistors 4,7к-10к, to 3,3v
But doesn't that will short circuit the SCK и SDA?