CFW for KSGER/Quicko STM32 Soldering Stations

[LILO]

Possible. But it doesn't eat too much, microAmps according to datasheet. So, I opted to leave it there. Doesn't worth an effort.
And probably one day we'll find a use for it ))

Another interesting idea could be to replace the bat with supercap, and program stm to charge it. Not essential at all, just thoughts aloud ))

[clytle374]

Another interesting idea could be to replace the bat with supercap, and program stm to charge it. Not essential at all, just thoughts aloud ))

I ran the math for a couple days trying to work that out. Self discharge is what gets you. I do love the idea. I built a bench power outlet that uses super caps to keep the display up for a couple hours when the output is shutoff.   But wanted to design something that works with this firmware.   

[spleenharvester]

Revised version of the T12-958 V2 schematic attached, fixed lots and lots of errors. I need to get the capacitor values but I think it is otherwise complete

[DavidAlfa]

It's the FW working correctly then?
Post some calibration values as reference.
The menu should go down when rotating the encoder clockwise.

As for Vbat, I have a small 50mAh battery from a broken bluetooth earbud, connected to 5V through two series diodes to drop the voltage and a 100R limiting resistor, stays at 3.6-3.7V and the settings haven't been lost after a month off.

[spleenharvester]

It's the FW working correctly then?
Post some calibration values as reference.
The menu should go down when rotating the encoder clockwise.

As for Vbat, I have a small 50mAh battery from a broken bluetooth earbud, connected to 5V through two series diodes to drop the voltage and a 100R limiting resistor, stays at 3.6-3.7V and the settings haven't been lost after a month off.

I'm still waiting on my replacement T12-958v2 as I tore the display cable on the first one so haven't tested it yet, but will update when it arrives

Edit - Attached finished schematic with capacitor values, I consider this done now. Hope this helps someone.

[LILO]

Busy weekend. Didn't have time to calibrate it yet. Will update once I do.

Do I understand correctly that NTC temp is the reference point, i.e. CFW assumes that NTC temp is equal to the thermocouple cold end temp and uses it to calculate actual tip temp?

[LILO]

NTC
Pull up 10k
Res 9k (measured at 25C)
Beta 3500

Quicko CF4 tip
Cal 250 1500
Cal 400 2400

[DavidAlfa]

Thanks.
So that's pretty much the same after all.
The amplifier gain is lower (x201 instead x250) so it makes sense the calibration values is lower.

This gain allows up to 410ºC with genuine C245 tips, where in other KSGERs it will saturate at 330ºC.
Thus no modification is required for normal temperatures (Unless you want 450ºC)

Please upload the original FW when you get it!
Alternatively you can extract it with some attack method like stm32f1-picopwner.

This board is now supported from v1.13.11.

[LILO]

Original fw is on previous page
Q958V2.zip

The dump is verified, I flashed it back after playing with CFW and it works.
And actually there was no read protection. Usual 'st-flash read...' did the job.

[LILO]

[Edit - Attached finished schematic with capacitor values, I consider this done now. Hope this helps someone.

Some corrections, as I saw it.

Buzzer, emitter goes to ground.

For RTC
VCC2 goes to +3.3 it's main supply

[spleenharvester]

[Edit - Attached finished schematic with capacitor values, I consider this done now. Hope this helps someone.

Some corrections, as I saw it.

Buzzer, emitter goes to ground.

Is BOOT0 grounded out then? The emitter trace actually leads to BOOT0, which itself seems to have continuity to ground? I thought maybe this trace was responsible for the 'beep of death' when the firmware is incorrect.

For RTC
VCC2 goes to +3.3 it's main supply

Right you are, will fix this in the next release!

[LILO]

It's trivial switch, load in collector, emitter grounded, base is control signal. So, BOOT0 is also grounded. And AFAIK it should be, unless you gonna do something unusual during boot process.

[LILO]

Update on NTC settings.

Pull up 10k
Res 10k
Beta 3950

Checked at several points from 25 to 80 C.
Looks close enough.

[spleenharvester]

Updated schematic of T12-958v2 attached. Changed BOOT0 to GND, fixed the RTC and added a missing 4K7 resistor on +3V3 in the ADC area. Let me know of any more issues. If anyone else with a T12-958v2 could check the ADC section that would be great, I have checked and re-checked and it seems to be correct but some on Badcaps can't make sense of the circuit (it seems to trip at 25A which seems high?).

[DavidAlfa]

In my calcs it tripped at 65A?

[spleenharvester]

In my calcs it tripped at 65A?

Do you think the schematic is correct then? Over on Badcaps they thought it should trip at closer to 2A and hence I might have gotten something wrong on it, but I've checked repeatedly and can't find what I would have missed

[DavidAlfa]

If you have a 2.5V reference through a 20k/3K divider, the output is 326mV.
You'll need 65A to have this voltage drop over 0.005R (5 milliOhms).