Soldering iron driver v1.5 PCBs are available at Seeed

Hardware hacking is more fun with open source, DIY tools. That’s why Arhi designed a completely open soldering station controller motherboard. And we designed a through hole version that is now available as a PCB only at Seeed for $7

The completed PCB is the heart of a soldering station, able to control several types of name-brand (and clone) soldering iron pencils. The key to this universal design is the analog front-end which is capable of reading both thermocouple and PTC temperature sensors commonly used in most soldering irons.

Tip status is monitored by a mircrocontroller, and accurately adjusted via PID temperature control. Temperature, configuration, and calibration settings are shown on a 2×16 character LCD display, and controlled with rotary encoder knobs. Soldering pencils currently tested by the community include Hakko 900 series irons (most commonly cloned soldering iron), Solomon irons, and Weller PES51 irons.


  • Compatible with most PTC or TC type soldering irons
  • Accurate and adjustable PID temperature control
  • Potential for USB data logging, and firmware updates
  • UART/serial data logging
  • Uses a HD44780 2×16 character LCD
  • Low noise, zero crossing AC heater control
  • Dangerous Prototype’s version is public domain (CC-0)

This is just a PCB. You will need to source parts, a transformer, and most importantly a suitable fuse.


This PCB is intended to be used with hot pointy things and dangerous voltages. This is a community developed board, copies are available to interested experimenters. NO SUPPORT OR WARRANTY IS AVAILABLE WHATSOEVER. This project is not recommended for everyone.

Grab a PCB from Seeed for $7.

Join the Conversation


      1. Can anyone take a look at the BOM an correct it?
        Resistors: R1-R21,R10-R21,R13-R17,R20-R24 = 10k
        R9,R19,R21,R27 = 1k

        The same R numbers are used again and again..

  1. “This project is not recommended for anyone.” Do you mean this project is not recommended for everyone? If it is not recommended for anyone, why sell it ;)

    1. It is just a disclaimer in case someone who doesn’t know what they are doing tries to build it.

      How many people have been around the block enough to know if their soldering iron is PTC or TC? I can see a kid who doesn’t know what he is doing try to become a star overnight but should beginners be hooking up transformers and finding a suitable fuse if they don’t know what they are doing?

      How do you know what a dangerous prototype is unless you find it?

      1. You’re right. I intended it be nobody. This is a dangerous experimental concept and I really want to emphasize that there is zero support. We put it up because it is a cool concept, but nobody should try in practice :)

  2. Ordered two of this, just for trying to see if it will work, maybe learn a bit about it.
    Since Hakko is way overpriced in Norway, I currently use this:
    very cool soldering station, but why not try out more :)

    I guess support, well, why not ask in the forums, that should be ok?, but the wiki pages lacks lot of info currently?, lot of places I see 600px, 250px and so on..

    1. Got a question, does the digital soldering IRon only PWM the 19V supply? (could you post back and fron closeup pics of it)
      If so then your 50W iron is only used at 30W, the Soldering Iron driver uses all 50w, but it does requires a chunky 50W transformer :)
      (at 12V the digital gives only 12W of power…

      as per the documentation, I’m working on it and it’ll be finished soon. End of week at the latest :)

      1. Another problem with PWM of a DC voltage is decreased heater element life due to electromigration which has been discussed in the SID thread in the forum. Looking at picture of the driver, it looks like a single output transistor in a TO220 package. You can eliminate this effect by using two half bridge drivers but probably easier just to use an AC power source.

      2. I use an Dell PSU, PA-6, it delivers 20V DC, 3.5Amps
        At least, it works very good for the price, the Hakko seller in Norway is taking $272 for the Hakko 888, and $731 for the 951..
        I found an seller in UK that have it at more normal prices, but he is not allowed to sell it outside UK, so for now I have to do with this.

        And regarding dc, pwm etc, well, the pencil costs me $9.. and replacement heater $6, so I have one heaterlement, and one new pencil as spares..

  3. An highly experimental means a higher commercial product liability. The disclaimer is correct that you buy that board at you own risk.

  4. Got these pcb’s today, fantastic quality of these boards! (atleast first impression)
    Now, gotta find parts..

Leave a comment

Your email address will not be published. Required fields are marked *

Notify me of followup comments via e-mail. You can also subscribe without commenting.