HAKKO (907ESD) and SOLOMON (SL-10/30) soldering iron driver

A place to document your own projects.

Re: HAKKO (907ESD) and SOLOMON (SL-10/30) soldering iron dri

Postby arhi » Sat Sep 03, 2011 8:53 pm

I finished moving my office (from one appt to another) and I will move most of my electronics equipment there but I still want to keep at least one soldering iron home so I decided to use one small ABS box I have and pack one small driver for solomon in.

I'm using COG 16x2 display from mikroelektronika that is fairly cheap (5$), simple to drive (standard write only protocol) and uses next to none power to operate :D

Image

I'm using the last switching schematic I tried since I measured whole circuit draw between 5 and 20mA (depending on if the heater is on or off, if the heater led is attached etc). With this 22mH 60mA inductor the output is steady 5.0V, the ripple is negligible (As I have few 1000uF there :D on the output) and nothing is getting hot. The power factor ain't big. Attm 25V being put in at 7.77mA (194.25mW) and 18.5mA is being drawn at 5.0V (92.5mW) so bit under 50% .. it would probably increase if I used higher frequency (smaller Ct) but .. it works as it is .. for the main driver (back lit display) I'll have to wait for the high current inductors to arrive.
User avatar
arhi
Hero Member
Hero Member
 
Posts: 2160
Joined: Thu Jun 24, 2010 11:41 am
Location: Belgrade, Serbia

Re: HAKKO (907ESD) and SOLOMON (SL-10/30) soldering iron dri

Postby Folknology » Sun Sep 04, 2011 7:48 am

I may be speaking out of turn here (being new to the forum etc..) and I also don't know what your driving principles/goals are for the project but you could probably reduce the cost of this unit by using a 3 digit led common cathode display (< $1) rather than the LCD. by adding a uln2003 or similar (also v.cheap) to drive the cathodes and 3 of the spare darlingtons instead of the 3 inverters (uc3) you would not increase chip count. Also the display could be mounted on the board itself which is useful when looking at enclosures etc..

Also you could loose some of that component duplication (like R19-24 not sure of the purpose of these) except where it accounts for different soldering iron types.

Just tell me to shut up if I'm interfering, I won't be offended!

regards
Al
Folknology
Full Member
Full Member
 
Posts: 130
Joined: Fri Sep 02, 2011 5:54 pm

Re: HAKKO (907ESD) and SOLOMON (SL-10/30) soldering iron dri

Postby ian » Sun Sep 04, 2011 10:52 am

All good suggestions, al, we never turn down input. My aoyue uses 7 segment blocks, but i would like a full lcd in my personal build. I have big plans for a setup and calibration interface :)

Arhi - according to the docs, the aoyue is 38watts, 24 volts. I will tear down the box later in the week for any hints about the iron type.
User avatar
ian
Crew
Crew
 
Posts: 10803
Joined: Mon Jul 06, 2009 6:14 am

Re: HAKKO (907ESD) and SOLOMON (SL-10/30) soldering iron dri

Postby arhi » Sun Sep 04, 2011 11:00 am

:D :D :D

- I use lcd because I actually have bunch of those compared to 7segs that I don't have, because they allow for nice user interface and because even when I don't have them they are cca 5$ so the "save" would be "negligible" when making "one off" device .. when making hundreds, yes, it would make whole lot of sense... I also seriously hate 7segs, when I have to use them I chose to drive them with 74HC595+ULN200x and to not multiplex them ..

- Since I use transformers, big ones, and since I hate when I move the cable and "device housing" start moving I actually put the transformer in the box so the box is heavy - stays in place, only mains cable exit box, and it's, in my case, required to have a cable between lcd and pcb. I actually also attach triac via cable and not on board (that's why on original board I had triac in the middle of the pcb) as I mount it on the heatsink and to the box itself

R19-R24 "duplicates" are there because I can't find 24K resistor locally (not a single store has them !!) so in first version I made those monuments from 3 resistors on the single resistor pad, now I added pads for 3 resistors. I could remove the original 24k from the pcb but what if someone has 24k available? I know you can purchase (just not here). I also don't see them increase price of anything, you don't put them on board and "complexity" of the pcb don't affect it's price

Just tell me to shut up if I'm interfering, I won't be offended!


oh no, please keep it coming. donno about others but I often get so shoved up the ass of my own project I can't see obvious things. These questions tend to snap me back into reality :D - they also help other ppl following up the project understand what they can change and why

as for most of "useful" projects I'm making I'm "getting the job done with what I have attm". I need bunch of soldering irons (some at home some in workshop) and I have bunch of these good pencils without drivers, so I decided to make a driver. Made first years ago, now I needed another so revisited the old project. I'd never initially decide to use 16F690 for this project. I'd go with some 18F device if I was "choosing" based on "what's best to run this", but I have 7 or 8 16F690 left in my drawer and I want to use these puppies up, so if a project can somehow fit in 16F690 - I use 16F690 ("I, the idiot" purchased 100pcs of 16F690 "by accident" so I'm using them wherever I can :D under 10 left :D ) ... also for e.g. using DS18B20 is for sure not the most optimal way to get cold joint temperature :D but I have 5 or 6 of them left collecting dust, I know they are not cheap but I have them .. so why not use them. It's open project, anyone can decide to make a change and use whatever is for them more accessible device :D ... also the moc I'm using is zero crossing, you do not need to use zero crossing, nor you need to use 1mA version ... you can use normal 10-20mA version without zero crossing, for a heater it would work just as good, only, I have 10 of these in the drawer and no others .. next time I'm ordering moc's I'll order some "regular" ones too but for now I'm using these zero crossing low current ones.
User avatar
arhi
Hero Member
Hero Member
 
Posts: 2160
Joined: Thu Jun 24, 2010 11:41 am
Location: Belgrade, Serbia

Re: HAKKO (907ESD) and SOLOMON (SL-10/30) soldering iron dri

Postby arhi » Sun Sep 04, 2011 11:12 am

ian wrote:according to the docs, the aoyue is 38watts, 24 volts. I will tear down the box later in the week for any hints about the iron type.


So the heater should be around 15R ... make sure you open it up and figure what's ptc and what's heater, the variable resistance of heater wire makes this checkups nasty ..

As for the interface it would be fairly simple (on 18F with enough flash) to make a simple calculation matrix for the calibration. You measure the iron in few points and you enter these points trough interface, firmware stores the table with data and do all calculation using it. I wanted to do same but 16F690 don't have enough flash for that exhibition :(. The big problem is really the way to set/measure temperature of the heater. We are working with 200-500C temp range and 250-450C range is where we would like to have controller as precise as possible. To set and measure this temp is "nasty", you need some medium (usually some oil that does not burn at 250+ so corn/olive/sunflower oil can't be used, maybe peanuts?, some high temp machine oil ..) where you submerge your heater and your thermometer.. and then you wait for everything to equilise and then you read info from adc and compare to measured temp. It is slow and dirty process and the "medium" sticks to your heater and is hard/impossible to remove it later and ... naaasty ... That's why I like solomon handles - they come with Ktype thermopar that is well documented. HAKKO comes with darn PTC with no datasheet :( so you need to make the table yourself
User avatar
arhi
Hero Member
Hero Member
 
Posts: 2160
Joined: Thu Jun 24, 2010 11:41 am
Location: Belgrade, Serbia

Re: HAKKO (907ESD) and SOLOMON (SL-10/30) soldering iron dri

Postby Folknology » Sun Sep 04, 2011 12:34 pm

Thanks Guys

In that case can you try to keep the display code as a separate module (where possible) so that some of us can use the 7-seg approach.

I need to try and work out the details for my target iron, I know its 48 Watt 24vac,but not sure what its using for temp feedback, by the looks of my dead element (replaced) it has 2 different metals on the lead which suggests thermocouple. My iron also has a round 4 pin connector so I will need to improvise there also!

I'm no pic expert but does the 16F690 have a pin compatable bigger brother with more flash maybe for the tables etc..?

regards
Al
Last edited by Folknology on Sun Sep 04, 2011 2:11 pm, edited 1 time in total.
Folknology
Full Member
Full Member
 
Posts: 130
Joined: Fri Sep 02, 2011 5:54 pm

Re: HAKKO (907ESD) and SOLOMON (SL-10/30) soldering iron dri

Postby sqkybeaver » Sun Sep 04, 2011 2:01 pm

i have a few max7219 and i want 2 rows of 7 segs on mine, as long as i can get to spi i'm good
User avatar
sqkybeaver
Hero Member
Hero Member
 
Posts: 1095
Joined: Tue Dec 07, 2010 8:50 am
Location: New Hampshire, USA

Re: HAKKO (907ESD) and SOLOMON (SL-10/30) soldering iron dri

Postby Folknology » Sun Sep 04, 2011 2:03 pm

My iron looks a lot like the one pictured here (sl-30), but the connector is different : http://ep.yimg.com/ca/I/yhst-1771922897 ... _184146561

If they are the same and I am sure that they are, these have been used in many different temp controlled soldering iron products.

regards
Al
Folknology
Full Member
Full Member
 
Posts: 130
Joined: Fri Sep 02, 2011 5:54 pm

Re: HAKKO (907ESD) and SOLOMON (SL-10/30) soldering iron dri

Postby arhi » Sun Sep 04, 2011 8:46 pm

Solomon is one of the biggest OEM soldering equipment manufacturer in the world. You can find that many brands are actually solomon with different connector and different sticker. If you have a multimeter with thermocouple input (many cheap 2$ made in PRC ones do) you can try to attach leads you believe are probe and test the output :)... if you have working controller measure voltage on pins, if you have non-working controller open it up and check out what kind of control it is doing.

As for the SPI on a 7seg there's enough pins to do it .. (IIRC I left hardware SPI free on 16F690). Wrt "modules", it's not that easy. Concept when running 7seg and when you are running LCD are imho too different, with lcd you display info you want, with 7seg you need to improvise. All the "alphabet" ppl use on the 7seg is for me too ugly, disgusting and not something I ever want to use myself. For e.g. I have a very nice PID controller for heating/cooling units. Darn thing allows you to set 2 different channels, pid parameters, warning values, type of sensor and whole bunch of other stuff. Comes with a darn book filled with "what you need to press to get stuff done". It has 3 7seg's, 4 leds and 4 buttons. Using the darn thing is impossibly difficult. Changing a single value require you to go trough many steps .. I changed sensor type on it 20+ times and still when I need to do it I have to consult a book - that's how "intuitive" the 7seg is. And darn thing cost arm and a leg... When you use a LCD you have nice big letters and numbers and anything you like showing all the data you want it to show, you have menus with text explanations etc. You do not need a bloody manual to store a startup temperature of your device .. you just go trough menu .. and with lcd costing 5$ ?!?! what's the point going 7seg? (the "better visibility" is argument I do not agree with, first I don't look at temperature on my iron while soldering that often at all and I never look at the temp of my soldering iron from 10m away, darn thing is never more then 50-100cm away from me and any decent back lit lcd can be read without a problem from 5m away...
User avatar
arhi
Hero Member
Hero Member
 
Posts: 2160
Joined: Thu Jun 24, 2010 11:41 am
Location: Belgrade, Serbia

Re: HAKKO (907ESD) and SOLOMON (SL-10/30) soldering iron dri

Postby Folknology » Mon Sep 05, 2011 5:00 am

Your display sounds really cool and very functional and will probably look the part also.

For me however, less is more, I like 2 basic settings - lead and lead free (pre-set temps), I tend to use the same types of solder, even the 7-seg is overkill 95% of the time as I don't actually need to know the temp, just that its where it should be! Occasionally I need to boost it for things that have a heat sink or large pcb contact area. As for setting PID values through menus that's far too much hassle for me I just want to get the stuff done, once those settings are optimised I don't touch them.

Thus for me operation would be 3 modes:
1) Leaded (pre-set 1) default
2) Lead free (pre-set 2) mode button
3) Manual temp - encoder

On a rare occasion of say changing an iron/element or something that needs p changes:
To set parameters such as PID values, hold down mode button (until display flashes) and rotate encoder knob for value and then press button again, mcu goes through all user parameters until finished. should not need a manual.

P.S. Yes I know some of the units out there are mind bogglingly complex and difficult to use, products from the institute of sh*t design, I am amazed at how badly some user interfaces are created so you have my sympathies I have been there also!

P.P.S That one of the cool things about open hardware you can make it whatever you want :-)

regards
Al
Folknology
Full Member
Full Member
 
Posts: 130
Joined: Fri Sep 02, 2011 5:54 pm

Re: HAKKO (907ESD) and SOLOMON (SL-10/30) soldering iron dri

Postby ian » Mon Sep 05, 2011 6:09 am

I think I'm running out of pins on a 18F2550. There are 15 free pins after adding xtal, time-keeping xtal, MCLR, USB, power, ground. Maybe the 32.768khz isn't needed, I don't want a battery backup after all so it won't be a great clock. That would free up 2 for 17 free pins.

1 thermocouple
1 heater control
1 temperature sensor
1 LCD backlight control
6 LCD control
1 PWM LCD contrast control
1 PWM Thermistor adjust (???)
1 or 2 Thermistor ground and power (could combine into 1 with NPN/PNP pair control)
3 INTERRUPT (?) interface buttons/encoder
17 total

I know it's probably silly, but I want to automate the iron selection so I can play around with automated tests. I'm not sure the best way to do it. ONe way would be a PNP high side switch and a NPN low-side switch to enable/disable. I thought it would be cool to do the adjustment with a PWM, but I feel that's going to be too noisy for an analog reading.

Maybe the Thermistor could be powered and grounded directly from the PIC pins. I'm not sure what effect RV2 and R29 would have when connected during thermocouple mode. Even if the PIC pin is hiz, I think the variable resistor will load the thermocouple.

Latest files attached.
Attachments
solderingironcontroller.sch
(420.39 KiB) Downloaded 706 times
solderingironcontroller.brd
(375.3 KiB) Downloaded 595 times
sic.png
User avatar
ian
Crew
Crew
 
Posts: 10803
Joined: Mon Jul 06, 2009 6:14 am

Re: HAKKO (907ESD) and SOLOMON (SL-10/30) soldering iron dri

Postby arhi » Mon Sep 05, 2011 10:49 am

ian wrote:I think I'm running out of pins on a 18F2550. There are 15 free pins after adding xtal, time-keeping xtal, MCLR, USB, power, ground.


dump 32768 xtal and use zero cumulative error alg. It works as well as 32768 basec clock (often even better as often you get lower ppm devices at higher speeds)..

dump mclr and use it as input pin

- that's 3 pins saved :D

1 LCD backlight control
1 PWM LCD contrast control


I never use this from mcu. In best case I leave the pot's accessible trough the case holes. I really don't see me needing to change any of these via menus. This saves 2 pins + it saves memory for setting these in menus.

1 or 2 Thermistor ground and power (could combine into 1 with NPN/PNP pair control)


adding transistors to thermistors kills the precision a lot, increases the acquisition time and increases the noise. Not really a good solution. Now I'm not sure about some things here. Thermistor adjust?! what is that?

Note that you need to have an "ambient temperature monitor". It is required with the thermocouple and it is also necessary for the auto detection.

so by my calculation you need

  • 3 [input] for button+encoder (interrupt on change pin's preferably for 2 of them)
  • 6 [output] for LCD (using write only protocol with 6ms delay instead of reading the busy)
  • 1 [output] for heater
  • 1 [analog input] for analog input from 240x amplifier
  • 1 [(analog) input] for local (analog) NTC or (digital) ds18b20

  • 2 [usb] for usb

That's about it 14 pins, and one of them can be MCLR :) (button for encoder). That more then fits in the 18F2550 :). You can even add few pin's for few "presets" :) (I'd link all available pin's to presets buttons)
User avatar
arhi
Hero Member
Hero Member
 
Posts: 2160
Joined: Thu Jun 24, 2010 11:41 am
Location: Belgrade, Serbia

Re: HAKKO (907ESD) and SOLOMON (SL-10/30) soldering iron dri

Postby arhi » Mon Sep 05, 2011 11:33 pm

This is I think "final" version of this design. Not much to be done here (except change the mcu and then push more functionality to it). It works, the Solomon handle works perfectly (Ktype thermocuple sensor) and the HAKKO (ptc sensor) works satisfactory (I'm not sure the offset and slope values are correct as I'm unable to measure temperature of the tip reliably in 200-400C range).

There's bunch of redundant stuff on board (one resistor or three resistors in 2 places, 7805 or switching circuit etc etc ..) and the pcb ain't that pretty but all in all - it works.

Further improvements
- add a voltage reference so that temperature readings are even more precise
- add few more buttons for some temperature presets
- make 7seg display / lcd display as different modules
- add some real PID control
- auto detection of the sensor type
- add time/date, uptime and other interesting data on display
- software upgrade with serial or usb bootloader
- output temp data on usb or serial link
- cheaper ambient temp sensor (maybe it would be cool info to display ambient temp too :D )
...

But these really require a mcu with bit more flash and I really just want a soldering iron so for the solomon (ktype thermocouple) type I'm not changing nothing in the concept any more; wrt hakko iron I might decide to do input differently as just using voltage divider and then amplifying it 240 times might not be the best solution for this PTC as attm I see a very noisy response from the sensor. I remove the noise with a low pass filter in software but I need to find a proper way to read this PTC. I tested the same technique with NTC that I have datasheet to and the system worked flawlessly so it looks like this PTC in HAKKO pencil is "dodgy". I'm waiting for another original hakko pencil to arrive before I start working on the "fix" for the hakko driver.

Note that L1 must be rated for twice the current your logic is using. I measured 250mA max usage with big back-lit lcd. L2 is not necessary and can be replaced with a 0R "resistor" (or a piece of wire), but if mounted you need to be sure it is rated for the current you are drawing. For L2 it is not a big deal as it is very low inductance so they usually take more then 300mA.

What would be cool is to get
- pcb in kicad, all trough hole
- pcb in kicad, all smd

but I don't have nerves to do it myself
Attachments
screenshot7.png
kicad.zip
KiCAD version of the schematic (v3.2)
(39.77 KiB) Downloaded 519 times
screenshot7.png
Screenshot of the PCB v3.2
SolderingIronController 3.2.zip
PCB V3.2 (pdf + gerber +proteus), HEX v2.8 (picc sources + hex)
(685.86 KiB) Downloaded 925 times
User avatar
arhi
Hero Member
Hero Member
 
Posts: 2160
Joined: Thu Jun 24, 2010 11:41 am
Location: Belgrade, Serbia

Re: HAKKO (907ESD) and SOLOMON (SL-10/30) soldering iron dri

Postby arhi » Wed Sep 07, 2011 10:05 pm

I friend just noticed, on all my boards I have 74HC14 and in schematic I'm constantly using 74hc04. The proper device (pin compatibile) is 74hc14 (schmidt invertor) and not 74hc04 (normal invertor) as the point of this ttl device is to clean up the garbage from the mechanical encoder...
User avatar
arhi
Hero Member
Hero Member
 
Posts: 2160
Joined: Thu Jun 24, 2010 11:41 am
Location: Belgrade, Serbia

Re: HAKKO (907ESD) and SOLOMON (SL-10/30) soldering iron dri

Postby ian » Thu Sep 08, 2011 1:35 am

I can't get back to this project until after the Maker Faire, but I will simplify and go with your suggestions. I'll give up the automated control and opt for simple jumpers :)
User avatar
ian
Crew
Crew
 
Posts: 10803
Joined: Mon Jul 06, 2009 6:14 am

PreviousNext

Return to Project logs