Open-T12-Soldering-Station released

[slavoy]

I have the PCBs and am testing it. I noticed, that on your PCB one connection to the 4-pin i2c screen version (SDA) is not populated, there is no trace from the mcu. If you program it from the deividAlfa and want to simply use parts from the original KSGER T12 V2, the screen will not work. One need to modify the source code, the PCB or solder a little wire (which is ofc quicker and easier in my case ).
While examining the PCB, I also noticed that a single quite thin trace on the top layer is used to control the heater. In the original design, the power trace is double-layered with 2 vias. I suggest to consider it in future revisions.

[DavidAlfa]

This board uses KSGER v3 base, so it's SPI display:

[clytle374]

I have the PCBs and am testing it. I noticed, that on your PCB one connection to the 4-pin i2c screen version (SDA) is not populated, there is no trace from the mcu. If you program it from the deividAlfa and want to simply use parts from the original KSGER T12 V2, the screen will not work. One need to modify the source code, the PCB or solder a little wire (which is ofc quicker and easier in my case ).
While examining the PCB, I also noticed that a single quite thin trace on the top layer is used to control the heater. In the original design, the power trace is double-layered with 2 vias. I suggest to consider it in future revisions.

It's definitively for the 6 pin SPI display.  I'll check the ad and be sure I was clear about that. Did you not get a display?  Everyone that has ordered one has opted for the display.  Glad to see it was so easy to convert it. 

The track is thin and I intended for there to be a copper pour there, there was one at one point.  Of the ksger boards I had neither had traces on both sides.  The PCB calculators say it is okay, especially since the trace is so short.  I'll update the github sometime to make it thicker.  But I don't intend to run anymore batches of these. 

[wasyoungonce]

Many thanks. I’ll post back with my knob images of knobs

clytle374
Sorry for delay on knobs.  Received them but are back in hospital under knife soon so may be awhile

Cheers

[clytle374]

clytle374
Sorry for delay on knobs.  Received them but are back in hospital under knife soon so may be awhile

Cheers

Sorry to hear that, I'm on no hurry

[slavoy]

For today, I bought this expensive screen:
https://www.waveshare.com/1.3inch-oled-b.htm
SH1106 driver
Connected:
VCC (PCB) to VCC (OLED)
GND (PCB) to GND (OLED)
D/C (PCB) to D/C (OLED)
RST (PCB) to RES (OLED)
SDA (PCB) to DIN (OLED)
SCL (PCB) to CLK (OLED)
And it worked briefly like several times, then I get artifacts and now a steady horizontal line. Any chance to get it working? If no, tell me which screen to buy. I want to get it done asap. Took me too much time arleady.
//
Did a reset by holding down the encoder and I get a picture again for this one power cycle. After reset the power - again a line.

[clytle374]

I really don't know what to think about that.  Not sure if the processor isn't coming up, or the screen isn't.  Try interrupting the RST line?

It was designed around the 6 pin SPI screens. 

I made sure it works with the ksger display.  Why not use the 4 pin screen you had working before? 

ebay has lots of results for "1.3" oled 6 pin SPI" displays. 

[clytle374]

Is that display 3.3V?

[slavoy]

The whole confusion come down from the fact that I didn’t realize your PCB is for firmware version V3 which is different. In my previous post, the display worked because the board had only the MCU and loaded firmware for V2. I have a KSGER V2 and thought I could transfer most of the components (which was mostly true). However, after soldering the entire board and loading V3, it obviously didn’t work. I also had an issue with the op-amp, probably because I received a counterfeit one, but I swapped it with the "original" from KSGER PCB, and it works. Now, I’m just left with the display. I’ll try soldering it with short wires and connect CS directly to GND in a few minutes.
I see it works by the current consumption and heat.
It’s all due to my haste. I had a time frame for this project and rushed into it without a detailed analysis.

[clytle374]

The whole confusion come down from the fact that I didn’t realize your PCB is for firmware version V3 which is different. In my previous post, the display worked because the board had only the MCU and loaded firmware for V2. I have a KSGER V2 and thought I could transfer most of the components (which was mostly true). However, after soldering the entire board and loading V3, it obviously didn’t work. I also had an issue with the op-amp, probably because I received a counterfeit one, but I swapped it with the "original" from KSGER PCB, and it works. Now, I’m just left with the display. I’ll try soldering it with short wires and connect CS directly to GND in a few minutes.
I see it works by the current consumption and heat.
It’s all due to my haste. I had a time frame for this project and rushed into it without a detailed analysis.

A time frame always makes for a rough time.  I didn't have the board house populate the op-amp on the boards I'm selling because of that, that and they are expensive.  I can try to dig up where I got my displays from in a couple days, I don't have access to most of my stuff right now. I ordered one and tested it, then ordered enough to sell them as kits.  I had a similar issue of getting a blank screen on my reflow oven project and it would only come on after a reset, not on initial power up.  I'd double check the power, as I think the displays have voltage boosters to drive the display.  Some take 3.3V, some 5V, and some both.         

[slavoy]

Well, shortening the wires didn’t help, but I accidentally caused a short with my tweezers, and smoke came out of the MCU and the voltage reg 

I will check what else went up in smoke in the morning

[clytle374]

Well, shortening the wires didn’t help, but I accidentally caused a short with my tweezers, and smoke came out of the MCU and the voltage reg 

I will check what else went up in smoke in the morning

I know that feeling, try not to let it give you nightmares. 

[DavidAlfa]

It seems the display has no vreg on it so it's 3.3V only.
That wiring mess won't work properly at the MHz speeds the SPI interface operates, forget it!

[slavoy]

Burned: MCU, screen, opamp, 3.3V regulator. Mosfet seems to survive.

I have replaced all but opamp for now. The guy on auction sent me wrong chips of course (single buffers haha) and I got no spare. Will try to find one when I get home.
I also got an idea to replace bare oled screen from the old 4-pin module to that 7-pin fried one and tadaa  Works every time now.

[clytle374]

Burned: MCU, screen, opamp, 3.3V regulator. Mosfet seems to survive.

I have replaced all but opamp for now. The guy on auction sent me wrong chips of course (single buffers haha) and I got no spare. Will try to find one when I get home.
I also got an idea to replace bare oled screen from the old 4-pin module to that 7-pin fried one and tadaa  Works every time now.

Good deal, I'm glad you got it sorted out mostly.  I've lost all hopes in getting components from all but major dealers.  I honestly had the board house order many of the parts from Digikey just so I knew they would work.  I might have overkilled the op-amp specs, i don't know for sure. 

[slavoy]

The LMR50410 and the inductor 74405042068 are practically unavailable in Poland. Even if you were to order them from abroad, it's not very cost-effective for a hobbyist (Mousers shipping 20Euro lol). The inductor could probably be replaced with another one that's more readily available.
I also looked for other dc-dc converters in Poland that would be at least partially pin-compatible, but nothing interesting in that package was available at the time when I was assembling it.
For now, I used one pin compatible LM2940 to go down from 24V to 3.3V, for testing. It does get a bit hot, that's true, but you could try some cheaper solutions, like using two resistors to dissipate part of the power and maybe another LM7808 inbetween as it is done in KSGER V2—this might be sufficient and would be the cheapest option.
Maybe a single DC-DC converter directly to 3.3V, as long as it doesn't interfere with the thermocouple measurements, would also be a good solution, but it needs some tests.
As for the opamp in that package it is also problematic here. The OPA336N I bought on auction turned out to be a counterfeit. However, it is available in SOP8 packaging in the store. I dissasembled a portable Secure T12 iron and it uses GS8332 SOP-8 for thermocouple. Also the Quicko uses SOP8 LM358.

[clytle374]

The LMR50410 and the inductor 74405042068 are practically unavailable in Poland. Even if you were to order them from abroad, it's not very cost-effective for a hobbyist (Mousers shipping 20Euro lol). The inductor could probably be replaced with another one that's more readily available.
I also looked for other dc-dc converters in Poland that would be at least partially pin-compatible, but nothing interesting in that package was available at the time when I was assembling it.
For now, I used one pin compatible LM2940 to go down from 24V to 3.3V, for testing. It does get a bit hot, that's true, but you could try some cheaper solutions, like using two resistors to dissipate part of the power and maybe another LM7808 inbetween as it is done in KSGER V2—this might be sufficient and would be the cheapest option.
Maybe a single DC-DC converter directly to 3.3V, as long as it doesn't interfere with the thermocouple measurements, would also be a good solution, but it needs some tests.
As for the opamp in that package it is also problematic here. The OPA336N I bought on auction turned out to be a counterfeit. However, it is available in SOP8 packaging in the store. I dissasembled a portable Secure T12 iron and it uses GS8332 SOP-8 for thermocouple. Also the Quicko uses SOP8 LM358.

Ouch, I get stuff from Digikey in 2 days for $4.99.  20 euro would hurt.  I looked and shipping them into the EU is not something I'm going to suffer through. 
My first Ksger has a 24V to 3.3V switching supply and it's ADC noise is pretty bad, so I killed that option. Resistor droppers were considered. 

The switching power supply is designed with TI's web tool.  So all related part numbers were defined by the tool.   

I chose the OPA336N for the very low input bias current.  Not having details on the thermocouple used in the T12s, I error-ed on the side of caution.  It was the op amp used in a reference design for a thermocouple amp I found researching this.   

[RobtP]

I've been watching this discussion for a while, am interested in building one of these, the front panel on my KSGER has died. Haven't investigated what broke but I thought it would be fun to replace it by building one of these boards.

I'm in the act of ordering some PCBs from JLPCB for another project so I've added some of these to my cart. The estimated cost is $8.50 for 20 pieces (lead-free HASL) so there's no financial risk to me if no-one's interested but I thought I could buy some to send to anyone in the UK that might like to try it. Will take a while to deliver from China. I expect second class post would be around 85p once I have them, I guess if there is interest we can come to some kind of agreement about kicking some funds to the developers. People would have to source parts themselves, obviously.

Are there any objections to me doing this?

I've used the downgraded KiCAD file, which looks OK to my inexperienced eye but are there any known pitfalls I should look out for before I order? I don't need 2oz copper or anything like that do I?

[clytle374]

I've been watching this discussion for a while, am interested in building one of these, the front panel on my KSGER has died. Haven't investigated what broke but I thought it would be fun to replace it by building one of these boards.

I'm in the act of ordering some PCBs from JLPCB for another project so I've added some of these to my cart. The estimated cost is $8.50 for 20 pieces (lead-free HASL) so there's no financial risk to me if no-one's interested but I thought I could buy some to send to anyone in the UK that might like to try it. Will take a while to deliver from China. I expect second class post would be around 85p once I have them, I guess if there is interest we can come to some kind of agreement about kicking some funds to the developers. People would have to source parts themselves, obviously.

Are there any objections to me doing this?

I've used the downgraded KiCAD file, which looks OK to my inexperienced eye but are there any known pitfalls I should look out for before I order? I don't need 2oz copper or anything like that do I?

I would add a copper pour for the T12+ from the mosfet to the pads for the GX connector and the solder connector.  It's thin, it should be fine, but thicker is better.  I think I had my priority order incorrect on the original.  I changed it on the git for the Dev version of Kicad.  I just realized I never updated any of the pictures.  These changes won't be reflected on the downgraded version.  I'll attach a picture of what I'm talking about. 

Parts cost is higher than you think, but you've probably seen those discussions.

I don't have any objections to it, It's opensource.  I have some for sale but too much trouble to get into the EU,  I made it ROHS for that reason.  But it seems like a lot of trouble, so unless someone with experience with that wants to tell me how.  I also don't have any bare PCBs as after building the first prototype on a homemade PCB, I decided I was not doing that again. 

   

[RobtP]

Done that. Thanks! Not ordered yet, though. I probably will order order the PCBs, even if I decide not to buy the components and make the board it won't have cost anything much. I actually already have a few of those things already.

Even more of a pain to send to UK (not in EU any more), especially to my address.

[wasyoungonce]

ok after my Hospital stint.....my spine is over constructed like the eiffel tower....

I said I would try some different knob sizes on the open source to see if we can get a better fit.  To cut to the chase yes you can but cost is too much.   Its cheaper to use a 15mm encoder splined shaft. Here are some self explanatory pics.

Yes you can cut down the encoder a little but its far simpler to use 15mm encoder shaft.  I did see on aliexpress encoders/knob packages 15mm, 20 tick with push button.   These included similar knobs (to the medium type as used in Quicko station) that had "skirt" to hide the nut, quite cheap.

FWIW...I think its best to go to such, 15mm encoders with included knobs from aliexpress.   Buying larger knobs is too expensive

cheers

FWIW...stations are working great.  I received 10K Thermistors so are changing the ones in the irons i have...these appear to be 5K.   The Open source was set up for 10K thermistors, yes I can change these in settings but just as easy to swap them out.

Loving these systems,,,,,ordered a Pro's kit SS-331H desolder station (cheap enough and spare iron) as I'll be losing my current desolder systems.   Pity there are no T12 desolder systems.   The whole heater design of T12 precludes having a hole in the shaft!   But still!!!  I dont use them much but when needed...vac desolder is gold.


EDIT:  A link to 14mm splined EC11 push button encoders and knobs.   But note how postage has risen.   I find this a lot these days.  But I also find alixepress more reliable than fleabay.
https://www.aliexpress.com/item/1005005983134515.html?spm=a2g0o.order_list.order_list_main.25.21ef180205tSrf

[clytle374]

ok after my Hospital stint.....my spine is over constructed like the eiffel tower....

I said I would try some different knob sizes on the open source to see if we can get a better fit.  To cut to the chase yes you can but cost is too much.   Its cheaper to use a 15mm encoder splined shaft. Here are some self explanatory pics.

Yes you can cut down the encoder a little but its far simpler to use 15mm encoder shaft.  I did see on aliexpress encoders/knob packages 15mm, 20 tick with push button.   These included similar knobs (to the medium type as used in Quicko station) that had "skirt" to hide the nut, quite cheap.

FWIW...I think its best to go to such, 15mm encoders with included knobs from aliexpress.   Buying larger knobs is too expensive

cheers

FWIW...stations are working great.  I received 10K Thermistors so are changing the ones in the irons i have...these appear to be 5K.   The Open source was set up for 10K thermistors, yes I can change these in settings but just as easy to swap them out.

Loving these systems,,,,,ordered a Pro's kit SS-331H desolder station (cheap enough and spare iron) as I'll be losing my current desolder systems.   Pity there are no T12 desolder systems.   The whole heater design of T12 precludes having a hole in the shaft!   But still!!!  I dont use them much but when needed...vac desolder is gold.

Glad to hear you are doing better.  Thanks for all the leg work with the knobs. 

I change out the NTCs too. So much easier, and I know all my handles are the same afterwards. 

So happy to hear you are enjoying the unit.  A desoldering station would be nice. I have a cheap one and it is so great when it works, but it likes to plug up, and it's so slow to get to temp I avoid using it.