CFW for KSGER/Quicko STM32 Soldering Stations

[clytle374]

For some reason I decided to build a open version of this board.  Mostly after getting the latest version of the ksger. 

Is the OPA366N a good opamp for the tip temp?

The latest version of the board doesn't work with the battery as the battery only goes to the off board RTC and not to processors, I assume the MM32 they are using doesn't have a RTC onboard.  That's going away for sure. 

Decided on using a switching power supply like on my first station with the black pcb.  I keep second guessing this.

NTC is internal only on this version.  Is there a 'best' default value of NTC? 

Will post the schematic when I get it done.  Should this be here?  Or in a different thread?  Any interest? 

[DavidAlfa]

The fix is easy, just a small wire from stm32 pin 1 connected to the RTC battery pin.
Why? I don't know,aybe longer battery life.

For lower noise, don't use a 24->3.3V buck converter, better 24->5V, then use a LDO to lower it to 3.3.
Internal NTC will cause higher temperature drift, as you're designing it from scratch there's no excuse to do it right.

[clytle374]

The fix is easy, just a small wire from stm32 pin 1 connected to the RTC battery pin.
Why? I don't know,aybe longer battery life.

The RTC comment was just a heads up if the issue got brought to your attention. I kinda asked before since I was confused, but now that i've traced all the circuits out the battery doesn't send any power to the processor. I'm sure it was the cheapest option they could take, but still no idea why they added so many parts for a clock. 
 

For lower noise, don't use a 24->3.3V buck converter, better 24->5V, then use a LDO to lower it to 3.3.
Internal NTC will cause higher temperature drift, as you're designing it from scratch there's no excuse to do it right.

 
If I have room for the second regulator, plus just having a SMPS on the board could be an issue.  We'll see.

I'll just figure out what RTD is in the ksger handle and also add the option for one on the PCB if someone wants one with different handle.

I think you misspoke there, lol, no excuse to do it wrong either. 

[elektryk]

If I have room for the second regulator, plus just having a SMPS on the board could be an issue.  We'll see.

There are a lot of buck converters compatible with 7805 pinout. I used it successfully in my custom controller (5V version and 3.3V LDO), you can also use WE 173950536 or something similar.

[clytle374]

If I have room for the second regulator, plus just having a SMPS on the board could be an issue.  We'll see.

There are a lot of buck converters compatible with 7805 pinout. I used it successfully in my custom controller (5V version and 3.3V LDO), you can also use WE 173950536 or something similar.

Thanks.  The WE part is kinda expensive, I've used similar RECOM parts before, also expensive.

How can you buy a whole switching regulator for less than the parts just buy the controller chip?  I'm pretty much doing copy and paste from the  TI controller designer page.  People keep saying the newer SMPS are very quite, so I'm going to give that a shot 1st.  Should be easy to do a version 2.  The black pcb ksger I've used for years now has a SMPS and hasn't caused issues.   

[clytle374]

Looks like the ksger used 10K NTC.  Was getting everything setup to measure the betas and find the correct part numbers for them.  Then I found that 2 of the 3 new ksger handles don't have NTC in them at all.  So they fault my old controller too.  Too many variations to comprehend here anymore.

Who sells handles these days?  I can't keep track of what is what.  Are the quicko handles better with NTC and shake switches?  These have actual mercury switches in them, lol

[elektryk]

T12 handles compatability is a real pain, mine are all rewired to the same pinout and with the same NTC.
Not a big problem with NTC because you can switch beetween 10k/100k in FW or disable it completely, but it can be very difficult to find a stand that fits...

BTW I think it is worth to consider T245 also, it is a bit more expensive option, but heat up time is excellent.

[clytle374]

T12 handles compatability is a real pain, mine are all rewired to the same pinout and with the same NTC.
Not a big problem with NTC because you can switch beetween 10k/100k in FW or disable it completely, but it can be very difficult to find a stand that fits...

BTW I think it is worth to consider T245 also, it is a bit more expensive option, but heat up time is excellent.

Adding them is my current plan.  What NTC do you use?  10K, but several different options exist.  When you say "stand' you mean the thing you rest the handle in when not using it?   

I'm trying to make a simple, yet high quality PCB, and avoid feature creep.  Started to design a super cap circuit for the battery function tonight.  Had to talk myself down, lol.   The T245 doesn't have a thermistor iirc, I planned to have one on the board and jumpers to snip to choose, so that it not an issue.  I also think there is no shake function on the T245?  Does the firmware support it?  I have no interest if not.  I hate programming.

Another question I'm facing do I use only leads for the output jack?  Or also a 4 or 5 pin jack?  Looks like quicko never used NTCs?

Full disclosure.  My intention(providing I complete this) is to put everything I design and most of the reference and directions on github.  I have built several other things that I ordered a 100 pcbs for as it didn't cost anything significantly more(VTVM probe, battery eliminator, RF probe, clones of the heathkit probe shells, things I wanted to do anyway), so I think I'm going to setup an ebay store.  Not thinking it'll make any money, just as a hobby and being helpful. 

Which brings me to another point I've kinda been meaning to bring up.  David would loading your firmware onto them as a few dollar option be acceptable if I send it to you?  Really trying to just be honest and fair about it.

Parts are ordered, schematic is mostly done except for power and gnd to the processor, CADing the old board now to everything lines up with the faceplate, hopefully I'll mill a PCB tomorrow. 
     

[elektryk]

What NTC do you use?  10K, but several different options exist.

Any (small) 10k NTC with known beta will be good.

When you say "stand' you mean the thing you rest the handle in when not using it?   

Yes.

The T245 doesn't have a thermistor iirc, I planned to have one on the board and jumpers to snip to choose, so that it not an issue.

That's a good idea, I've got possibility to mount NTC directly on PCB but with T245 I've mounted it in a connector.

I also think there is no shake function on the T245?  Does the firmware support it?  I have no interest if not.  I hate programming.

FW supports shake mode and stand mode as well (T245 doesn't have vibration switch, placing handle in stand triggers standby mode).

[clytle374]

Any (small) 10k NTC with known beta will be good.

Had to educate myself on NTCs.  The numbers I found online for the ksger handle is BF58 10k B3950.  Since it seems that most handles with NTCs are probably ksger, using the same one would reduce issues if people are swapping handles.  When I went to digikey I can find 10K but had options for a B3950 in across categories of B0/50, B25/50, B25/75, B25/85, and B25/100.  Being that B25/50 results in many more parts I assume that is the correct category.  I need to find a hobby to relax, this one doesn't work.

That's a good idea, I've got possibility to mount NTC directly on PCB but with T245 I've mounted it in a connector.


FW supports shake mode and stand mode as well (T245 doesn't have vibration switch, placing handle in stand triggers standby mode).

Putting it in the connector makes a lot of sense.  Should be close to room temp, but doesn't catch the handle getting hot. 

I was asking if the firmware and hardware supported the T245, obviously the wiring needs changed a bit. 

I think the stand switch and the option of putting the NTC in the connector finalizes the decision to go with the 5 pin connector. It leaves room for an NTC being added, and a pigtail for a stand switch.   Leave solder pads for wires and some bites to snap that area of the board off to clear a connector if anyone needs too. Really wish that connector would come out the back of the front panel instead of the front.  I appreciate the advice.

[totalnoob]

That's a good idea, I've got possibility to mount NTC directly on PCB but with T245 I've mounted it in a connector.


FW supports shake mode and stand mode as well (T245 doesn't have vibration switch, placing handle in stand triggers standby mode).

I was asking if the firmware and hardware supported the T245, obviously the wiring needs changed a bit. 

Daves firmware does support the T245, when it comes to hardware the KSGER and Quickos and others that use similar boards can support either handle, but it takes modification (remove a trace) which I believe essentially makes it unable to be returned to be used in its original configuration.  Someone had a great idea, a page or two ago, that if you went with a 6 pin output, that would allow easy switching between a T12 handle and a T245 handle without modifying the hardware or use other means of "non-destructive" hardware methods of changing handle configurations that would likely require someone to open the station to do so (like using jumpers or a switch). Of course that would mean people who built your design would have to either get a new connector for their handles or use a patch cord if they use their handles on different stations that use the 5 pin connector.

Just a thought.

Good luck.

[clytle374]

Daves firmware does support the T245, when it comes to hardware the KSGER and Quickos and others that use similar boards can support either handle, but it takes modification (remove a trace) which I believe essentially makes it unable to be returned to be used in its original configuration.  Someone had a great idea, a page or two ago, that if you went with a 6 pin output, that would allow easy switching between a T12 handle and a T245 handle without modifying the hardware or use other means of "non-destructive" hardware methods of changing handle configurations that would likely require someone to open the station to do so (like using jumpers or a switch). Of course that would mean people who built your design would have to either get a new connector for their handles or use a patch cord if they use their handles on different stations that use the 5 pin connector.

Just a thought.

Good luck.

Interesting thought. Someone who is inclined to do such a thing could easily do that, I think, I haven't looked into the T245 handle yet.  I would like to keep it easy for the people that need easy.  I've thought about making face plates as an option so people wouldn't have to solder. But the displays are stupid expensive.  I don't know the answers yet, I'm not going to make any money competing against the Chinese brands.  But after buying this last controller I was fed up and decided to build one, actually I need 3, but I enjoy this.  I figured a few other people would want the same thing, so I'll share that.  Thought a kit would be nice, but it'd take more time to bag up the parts than build one.
 

[DavidAlfa]

Putting it in the connector makes a lot of sense.  Should be close to room temp, but doesn't catch the handle getting hot. 

No, the thermoelectric effect of the tip probe ends in the socket, where the tip is connected to the handle.
The generated voltage is based on the temperature difference between the hot and the cold part across the whole tip.
So, you want to read that junction temperature, not in the board or the connector.
If the handle gets to 45ºC, but you put the sensor somewhere else at 25ºC, you'll have a drift of 20ºC.

[clytle374]

Putting it in the connector makes a lot of sense.  Should be close to room temp, but doesn't catch the handle getting hot. 

No, the thermoelectric effect of the tip probe ends in the socket, where the tip is connected to the handle.
The generated voltage is based on the temperature difference between the hot and the cold part across the whole tip.
So, you want to read that junction temperature, not in the board or the connector.
If the handle gets to 45ºC, but you put the sensor somewhere else at 25ºC, you'll have a drift of 20ºC.

Yeah, that is what I was figuring since you need to read the temp of the cold junction to correct for it. 

Are the ntc settings constant? Or set up for each tip?

[dcore]

Daves firmware does support the T245, when it comes to hardware the KSGER and Quickos and others that use similar boards can support either handle, but it takes modification (remove a trace) which I believe essentially makes it unable to be returned to be used in its original configuration.  Someone had a great idea, a page or two ago, that if you went with a 6 pin output, that would allow easy switching between a T12 handle and a T245 handle without modifying the hardware or use other means of "non-destructive" hardware methods of changing handle configurations that would likely require someone to open the station to do so (like using jumpers or a switch). Of course that would mean people who built your design would have to either get a new connector for their handles or use a patch cord if they use their handles on different stations that use the 5 pin connector.

Just a thought.

Good luck.

When we cut the PCB trace to use T245 handles, we can rewire that cut connection inside the T12 handle socket.
This way it will keep working with both T12 and T245 handles.

Changing the number of wires in the handle is not necessary, it's additional work and cost.
Also some T245 handles are impossible to open and others very difficult.

The only thing we need to do to the handles (T12 and T245) is to change the wires order in the handle socket and put the said shunt in T12 handle socket to remake the PCB cut we did.

The ksger PCB has a 5 pin socket, with 2 ground PINs, we can isolate one of those pins from the PCB and rewire it to reconnect the cut trace inside the T12 handle socket.
Other option that was explained to me, is to stop using the NTC inside the T12 handle and use that wire to remake the said cut trace, this will avoid the additional work of isolation one of the ground pins from the PCB in an already made station.

Looking at the schematics will help understand the options for the already made stations.

[clytle374]

So, you want to read that junction temperature, not in the board or the connector.
If the handle gets to 45ºC, but you put the sensor somewhere else at 25ºC, you'll have a drift of 20ºC.

Any chance you are only sampling the NTC when the heater is off?  Laying out the board and being paranoid, then thought I should ask before worrying.  Thanks

[DavidAlfa]

Everything is sampled with tip power off. I can't understand how this would affect the layout?
Just copy any Quicko/KSGER design, but with better op-amp, ground planes, power decoupling and regulator design. I won't be making custom firmwares!

[clytle374]

Everything is sampled with tip power off. I can't understand how this would affect the layout?
Just copy any Quicko/KSGER design, but with better op-amp, ground planes, power decoupling and regulator design. I won't be making custom firmwares!

Because I crossed the heater on trace with the NTC signal under a resistor, hence the question. I want to be able to make the PCB on a mill and can't do plated through holes, so vias are limited to places where they can be soldered.   Not asking you to make custom firmware, that is the main design criteria.     

[DavidAlfa]

Do you expect your board to be better than Ksger when you're placing the lower vias posible?
Why not do it properly and order to jlcbpcb.
You can fit 3x pcbs in 120x102mm, so you'll get 15 PCBs for ~$4 including shipping.

[clytle374]

Do you expect your board to be better than Ksger when you're placing the lower vias posible?
Why not do it properly and order to jlcbpcb.
You can fit 3x pcbs in 120x102mm, so you'll get 15 PCBs for ~$4 including shipping.

I think I can do better. A better power supply, better opamp, better ground plane, actually read the STM32 on bypass capacitors as ksger obviously did not.  I will proof it out and then have them made.  I don't understand "lower vias"  I managed a layout that does not need many.  Maybe I'm missing something.  I do not believe this is a multi-layer board if you are referring to buried vias.   

[clytle374]

Parts are here, now I need to find time to build it.  Anyone have a lead on the OLED displays?  I got one from digikey made by adafruit and pinout is way wrong.  Another issue with flexible compatibility.

[cosmin1]

Hi everyone. Long time not loged in.
I was using one stm32 based board v2.1s with a jbc c210 tip.
Now i need a duplicate of that. I have the same board but with some reason, i can not access the MCU. The error is "read protection turned on". Can't read, can't write. MCU version is STM32F103. If i replace the STM, is it possible to copy the firmware from the other STM into the new one? In this case it will copy also the tip parameters stored in the old STM? Or do i have to calibrate again?
I wouldn't do that, i burned already 2 jbc tips when tried to calibrate... 😔

[oleg401169]

Hi everyone. Long time not loged in.
I was using one stm32 based board v2.1s with a jbc c210 tip.
Now i need a duplicate of that. I have the same board but with some reason, i can not access the MCU. The error is "read protection turned on". Can't read, can't write. MCU version is STM32F103. If i replace the STM, is it possible to copy the firmware from the other STM into the new one? In this case it will copy also the tip parameters stored in the old STM? Or do i have to calibrate again?
I wouldn't do that, i burned already 2 jbc tips when tried to calibrate... 😔

Why create a problem - install a new chip, flash it and, yes, you will have to calibrate again. It is advisable to install the original chip, problems may arise with clones. As a solution, you can buy a bluepill board with the original chip, they are sold on aliexpress, and many sellers have them as well they sign - just f103c8t6 and f103c8t6 original. I have a soldering station assembled on a c245 assembled on a bluepill board, there was a problem with the clones, but when I installed the board with the original chip everything began to work perfectly.

[DavidAlfa]

Can't read, can't write.

Hey cosmin, long time no see!
(Yeah I saw your WhatsApp, just too freaking busy!)

Check the option bits, clear RDP / WRP.
And yeah cloning a STM32 should preserve everything, there isn't anything device-specific in the CFW, only the original KSGER firmware will refuse to work as the stm32 unique ID changed, asking for the activation key.

About the C210 issue, no idea, it's connected in the same way as T12, but the output is much lower, about ADC 1500 for 400°C.
Try a manual calibration in CALIBRATION > SETTINGS.

Cheers!

[cosmin1]

Yes, it's connected as the T12. But in calibration process... it glow like a nice red bulb and burned out... 
So i was thinking if i copy the fw from a same version pcb already calibrated with the C210, maybe no need to calibrate again.