Chinese STM32 Oled soldering controller – Important Update

By | June 9, 2018

According to Stefan Trethan the connections on the JBC T245 tips are different than previously stated.

According to his findings, on this tips the thermocouple is between the outer sleeve and the inner contact, so if the inner contact is connected to the pulsed (PWM) 24v rail the iron tip will have approximately the same voltage (difference will be the TC voltage).

This will make things go boom if ground is connected to chassis ground, as suggested in order to use the stand sleep function. Even if this isn’t used, having the iron tip with such a large voltage is not ideal either.

The workaround Stefan found is to separate the TC reading from the heater element supply. This is achieved by cutting the trace from the output of the mosfet (as shown on the picture below. The inner contact of the tip is then connected to terminal 4 of the plug (the one connected to C7 and R8), the middle contact of the tip is connected to the output of the mosfet, and the outer sleeve is connected to ground.

Thanks Stefan for finding, reporting and fixing the issue!



15 thoughts on “Chinese STM32 Oled soldering controller – Important Update

  1. Morten

    On the subject of tips, genuine T12 Hakko tips seem to be a bit difficult to source here at the moment, but T15 are more readily available and are apparently a slot in replacement.

  2. bart

    im planing to update my soldering stations.
    I’m thinking about JBC stations but price is little bit to high for me and specially that i will need to buy two stations.
    I’m considering STM32 station (with black aluminium handle)

    I’ve found that firmware update that give possibility of using JBC tips.
    Main question is, is there advantage using that station with JBC tips ?

    I’m asking cos i’m planing to use that handle:

    with that tips:

    Asking cos i’m mainly soldering RG402 cables to 2oz pcb’s and to connectors. I also work with aluminium pcb’s.
    Doing it with stations that uses 900 tips it’s very slow and usually i must work with 450 degrees.

  3. Zorkun

    This link solder station on your code working . Please help wich board %100 working your code
    KSGER STM32 OLED 2.1ST12 DIY soldering station control board electric iron head welding handle tool,searchweb201602_3_10065_10068_319_5730615_10059_10884_317_10887_10696_100031_321_322_10084_453_10083_454_10103_10618_10307_537_5729315_536,searchweb201603_51,ppcSwitch_0&algo_expid=01af7387-e33a-4ce1-89db-634a0cecee22-0&algo_pvid=01af7387-e33a-4ce1-89db-634a0cecee22

    1. jose Post author

      The only station I’m sure this firmware works on is the one I have used when developing it, the one on the pictures present on this blog. No idea if it is still available or not. The firmware will be easily ported to any board using an STM32 processor. I have previously stated that I don’t mind porting the firmware to another board providing I have an unit to test with.

  4. Antonio

    Thank you very much for the project.
    I’ve broken C7 and I need yo replace with a new one.
    So, someone knows what is the value of this capacitor?
    Thank you in advance.

      1. Antonio Garcia

        Thank you Jose, I’ve installed C7 and it’s running now, but I’m using a C245 tip, and I need to SET the temperature to 425ºC to barely melt leaded solder.
        What could I do to fix it?
        I’m looking for some compensation options in the menu, but I didn’t have found.
        Thank you!

          1. Antonio

            Sorry, I’ll review from the first chapter.
            Thank you.

  5. Rodstar77

    Thanks for the project!

    I managed to compile the sm32 project and build the release and debug versions. Also managed to firmware update the ksger s micro controller.

    I had trouble with the voltage read being ‘incorrect’ by a growing margin as the voltage rose eg. -50 @ 200v -150 @ 350v. I fixed this with a brut force offset added in code (after maxing out the calibration). Am I missing something ?

    The debug build is unstable resetting itself after some ‘unknown condition’ is met. Looks like nearly all all the ram is used….


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