CFW for KSGER/Quicko STM32 Soldering Stations

[DavidAlfa]

Good job, getting close! What's that label in PD1?

[LILO]

Something in Chinese, empty pad next to gx12 connector. You can see on board photo.
Added display pins to the previous post.

[spleenharvester]

Awesome thanks, I'll add those into my schematic and hopefully between us we'll have it done! I'm hoping to finish it tonight.

I have no electrical engineering background and quite a rudimentary understanding of these circuits so it helps seeing them labelled, as I'm tracing it OK but have no idea what I'm actually looking at (that TL431DBZ section makes no sense to me at all and I have no idea if I've traced it wrong or just don't understand it lol)

I have 100% killed my station anyway, accidentally ripped off the LCD connector and some pads and probably not worth the hassle of doing trace repairs - so once I have a new station I am going to desolder the old one and try to get some values for the caps.

And yeah I'm not sure what that pad PD1 leads to is about either. If anyone knows Chinese maybe they can translate the label. I think it's also worth noting the 'earth' wire on the 3-pin header is connected to earth at AC in but literally goes nowhere on the board at all, I have no idea why they even included it

[DavidAlfa]

You're doing a great job!

[LILO]

That 431 for me looks more like Schottky diode, I may be wrong though. 5 legs part below seems to be lm321 opamp to sense tip current. But that schematics looks strange. I can't find feedback circuit.

As for your broken display... At least you have good case and PSU. You can buy replacement controller board and have working soldering  station ))

For earth connection I just bridged E and - on PSU board with blob of solder.

UPD:
431 could be TL431 voltage reference, yepp. But anyway I can't understand how that part of schematics is intended to work )))

[spleenharvester]

That 431 for me looks more like Schottky diode, I may be wrong though. 5 legs part below seems to be lm321 opamp to sense tip current. But that schematics looks strange. I can't find feedback circuit.

As for your broken display... At least you have good case and PSU. You can buy replacement controller board and have working soldering  station ))

For earth connection I just bridged E and - on PSU board with blob of solder.

UPD:
431 could be TL431 voltage reference, yepp. But anyway I can't understand how that part of schematics is intended to work )))

It's entirely possible I've just gotten it wrong    I'll have another look, it took me several attempts to trace that one

Also I ran those chinese characters through OCR, they come out as 座子 which apparently means 'seat', so whatever that means

[DavidAlfa]

Maybe it means "Stand" ?

[LILO]

Probably, some sensor in soldering iron stand.

[LILO]

So guys, what do we have atm?

I focused on control/sense/display signals and their mappings to mcu pins so far, assuming that is enough to configure CFW for this new flavor of control board. Do we need something else?

Nevertheless full schematics diagram is nice, hope we will complete it one day.

[spleenharvester]

Attached is where I'm up to now. Mostly fixes (including that 431 circuit which I didn't even have close to correct in my last schematic ). I think it is just a few more PA/PB pads and the op amp circuit near the WSF45P06 and then we're done. Will come back to it later this evening.

[clytle374]

I understand the fun you are having tracing the board.  I ended up stripping mine to be sure. 

So my testing is going along okay, I think. I wanted to show a pic of the debug screens to verify I have a acceptable result on the temperature reading circuit.  It was about 45C high at 400C  during initial calibration, my old ksger was the same when firmware was uploaded. 

  https://github.com/clytle374/Open-T12-Soldering-Station if anyone cares

[spleenharvester]

OK chaps I think we are done tracing the new T12-958, sans a few annotations and unknown components - see attached. Let me know if anything looks stupid and I'll double check it. Cheers

[DavidAlfa]

First test attached, following LILO's schematic.

Code: [Select]

RST:    PA3
DC:     PA2
SCL:    PA1
SDA:    PA0
ENC_L:  PB5
ENC_R:  PB6
ENC_SW: PB7
VIN:    PA4
NTC:    PA6
TIP:    PB0
PWM:    PA7
WAKE:   PA5
BUZZER: PB9


[LILO]

Awesome! Thanks.

At least encoder seems to work Ok. Now have to asseble it back and test.

[LILO]

OK chaps I think we are done tracing the new T12-958

Well done and nice looking! Will check it a bit later and provide corrections in case of any errors.

[LILO]

Looks good so far. Everything is working.
Now have to dig into all those tonns of settings. Calibration at first place. Both tip and ntc temps are shifted by approx 30degC. Tip is displayed lower and ntc is higher than they actually are.

Great thanks!

BTW here is original 958V2 fw dump, if anybody interested.

[spleenharvester]

Great work, thanks both for this! I look forward to testing it out when I get my replacement T12-958 

I'm also going to buy one of the new Quicko T12-A cordless stations, partly because I need one but also it looks like it might be the same controller - will report back whether it's compatible!

[LILO]

Should be something similar inside, but who knows. Maybe you'll get V3 )))

[LILO]

Battery mod dosn't work. Took it apart to check, and actually. VBAT pin is connected to VDD 3.3 instead of battery.
Fixable, but needs a lot of courage to deal with that tiny pcb traces.

[DavidAlfa]

Battery mod dosn't work.

Because it probably goes to the RTC VDD instead?

[LILO]

As I see it goes directly to board's 3.3V source. Battery is only used as backup power for DS1302 rtc chip.

[DavidAlfa]

Yeah I meant the battery, not Vbat pin.

[LILO]

I think it's easy to modify. Just cut the trace and route VBAT to the diode next to the battery with thin wire.
Should work, but later.

[LILO]

LOL
Cut the wrong trace and had to restore it. And VBAT actually hangs in the air. So, just short piece of wire and we have working battery mod.

[clytle374]

Might as well bypass that RTC chip, no point in it using the battery