Youyue 858D+ some reverse engineering + custom firmware

[raihei]

Hi folks,

I also ordered a Kaleep branded 858D+ from amazon germany (only 36.66€ at the moment!) and it came with a MK1841D3 chip.

I successfully did the following hardware changes:
- Rewired internal earth connection, because between power connector and gun nozzle I had around 20 Ohms. 
  Wired earth directly to the case, to the front plate and to the gun.
  Crimped the earth cable in the gun to the nozzle metal it was only twisted around as you can see in some other pictures in this thread.
- Added a heatsink to the TIP122 because it got really hot when the fan was running on lower speed. Is this usual?
- Soldered a adapter board based on wguibas great board and installed an ATMEGA 328P.
  The only problem I had was that the two 10K resistors for VREF=2.5V were somehow to high, the VREF pin pulled the voltage to 2.14V.
  So I changed the values to 1K and now I have a VREF of 2.5V
- I added a small buzzer (eBay auction: #222121496866) to the board because I like how the Hakko soldering stations beep when they have reached the setted temperature and to get an accustic feedback when the gun was correctly placed in the cradle.  Because of that, some changes in the custom firmware were necessary.

So here is my own custom firmware V1.47 based on V1.46 from madworm:

 * - Added an output (arduino pin 18, hardware pin 27 on a 168P/328P) for a buzzer which will beep on the following events:
 *   Power on (high beep)
 *   Set temperatur reached (only one time after removing gun from cradle and after changing temperature with the key buttons) (high beep)
 *   Put gun correctly back in cradle (low beep)
 *   Setted timeout reached (low beep)
 *   Keypress (comment out "#define KEYBEEP" in youyue858d.h to disable) (very high beep)

 * - Added a multiplicator entry (TPL) to setup menu for stations with samsung or MK1841D3 chip
 *   For stations delivered with atmel chip set multiplicator to 10 (=1, default), for stations with MK1841D3 set to 21-24 (=2.1-2.4)
 *   (According to the forum on some stations a value between 2.3-2.4 is correct, on my station with MK1841D3 2.1 was correct)
 *   Possible values 10 to 40 (= multiplicator 1.0-4.0)
 *   This change avoids a seperate firmware version (thanks wguibas!) for stations delivered with non atmel chips

 * - Added raw ADC value monitoring to the overtemperature shutdown process, because when you fiddle around with the multiplicator
 *   and set it wrong, temperature input may overflow which results in no shutdown on too high temperatures.
 *   Station will shut down and show "°C ERR" when analog input for temperature reaches 1000 (analog input is 10bit so max value is 1023)

 * - Changed standby display from "---" to "STB" because in my opinion it looks nicer :-)

 * - Added a delay time entry (DEL) to the setup menu which kicks in when the fan_off temperature is reached (default 45°C)
 *   to avoid fan off-on-off-on-off bevaviour because temperature rises to fan_on temperature again after fan was switched off.
 *   Delay will only be active if a temperature of 100°C was reached.
 *   Possible values 0 to 60 seconds

 * - Changed back max temperature to 450°C and shutdown temperature to 500°C because (depending on cal poti setting) 500° can lead to overflow of temp analog input.
 *   (If you set the cal poti to 100°C = 0.5V like me, this gives you 2.25V at 450°C.)
 
  Thanks to madworm, wguibas and all others here in this thread for a lot of useful information, the custom firmware and the adapter board which saved a lot of time!

Attached my firmware V1.47 (based on madworm's V1.46) as source and as compiled hex for the ATMEGA 328P and 168P.

Before first heating process, set "TPL" in setup menu according to your hardware:
- Original Youyue with atmega: 10 (=multiplicator 1.0) according to madworm
- Yihua with samsung chip: 19 (=multiplicator 1.9) according to wguibas
- Kaleep with MK1841D3: 21-24 (=multiplicator 2.1-2.4) 2.1 was correct for my station with 220V, wguibas figured out 2.3-2.4 for the 110V version.

You may also need to adjust the low and high limits of the fan, in case of my Kaleep station it was low 120 and high 320

raihei

[bitseeker]

Those look like good enhancements. Thanks for sharing them, raihei.

[dimkasta]

I just received mine from amazon.de
It is Uvistar branded and it comes with a CE sticker which is a bit reassuring.
I double checked mains wiring with my multimeter and I do not see any dangerous issues there.

It seems to work ok, although I do not see any sleep mode or magnetic sensor action.
This is a bit disturbing, so I will open it up later today and see if there are any issues with it.

My todo list for now is to verify proper earthing, fusing and DPST switching of mains power, and then check for miswired magnetic switch.

[dimkasta]

I found some time to check the wand.

The first issue was that the earth wire was just loosely wrapped around the metal, with strands flying every each way. It was probably shorting the magnetic switch.
I added some solder to the wire. Solder does not wet the metal on the wand but at least there will be no loose strands flapping in the wind in there.

The sensor now works, but I noticed that there is a magnet only on one side on the stand. This means that if you place the wand on the stand rotated by 180 degrees the device does not go into sleep mode. Not a big deal to work with, but I do not know if it is as intended.

The rest of the unit seems ok. I expected much worse. The only issue is the pour conductivity between the metal panels. Nothing some paint scratching won't solve though.

I hope to find some time to research the custom firmware soon

[bitseeker]

The sensor now works, but I noticed that there is a magnet only on one side on the stand. This means that if you place the wand on the stand rotated by 180 degrees the device does not go into sleep mode. Not a big deal to work with, but I do not know if it is as intended.

I don't recall if there's one switch or two for sleep mode. I thought there were two, although that's still not enough to guarantee no dead spots. You could always paint a spot or put a sticker to take the guesswork out of aligning it properly to the cradle.

[netdudeuk]

Is there any way that these (potentially wrongly wired) units could damage the 240v UK mains socket ring cabling ?  I'd like to get one myself but would like to know that it couldn't damage any existing equipment.

Thanks

[stj]

impossible, the most it could do is blow it's fuse.

[dimkasta]

Provided it is actually fused, and the fuse is on the live.
It is quite difficult to predict what a randomly misswired device may do.

At least check it with a DMM for obvious faults. There is another thread that has more info.
And make sure your mains panel is properly wired with all the protective devices required in your area

[compman2]

I would like to get one of Wayne's adapter boards for the MK1841D3.  Are they still available?  What is the process?  I have tried PMing but haven't gotten any reply.

[stj]

Provided it is actually fused, and the fuse is on the live.

in the u.k. the negative and earth are bonded together, and the plugs are all fused - no problems.

[netdudeuk]

What fuse should go in these ?

[ass20]

hi
anibody, do you have pin out of fan handle?
please post it

[Nprod]

I would like to get one of Wayne's adapter boards for the MK1841D3.  Are they still available?  What is the process?  I have tried PMing but haven't gotten any reply.

I'd love one too,waiting for a reply as well. Incidentally, has anybody tried adding a female connector to these stations? From what i've read, older Youyues had removeable handpieces, but the connector had exposed pins with mains AC on them so they switched to wiring them directly. I was thinking why not add a female connector like this instead:



It would make the station a bit more portable and easier to store and move around...

[bitseeker]

Reversing the gender of the connectors makes sense for safety. Give it a try. Mine has the killer male connector on the station.

[tambaki]

Hello! Guys help me understand Do not know what is the problem in the firmware or hardware! Baku 861d station with chip MK1841d3 (adapter 328p firmware 1.47) when the (hair dryer is in the holder), the display shows the firmware 1.4 cooler turned on for 5 seconds and turns off the display lights STB (---), pressing the buttons work, but if you remove the hair from the stand disple? it all goes silent hair dryer! Where to dig prompt! Programming is only beginning to learn!

[Jonas-fr]

My project for a replacement controller for the 858 has progressed, I've ordered the first batch of PCB today.

You can follow progress here:
https://github.com/0xPIT/Air858

Hi 0xPIT

I've got the same WEP 858D+ Samsung based rework station as you, would be ready to make some test of your PCB if you're selling one. If you've got one with components (as kit or presoldered) I'm also interested. Let me know. Cheers

[tambaki]

Thanks to all! I found what the problem is! baku 761d chip MK1841d3 adapter 328p with a small alteration of a button in place of the encoder works fine!

[Satscript]

Hi all. Has anyone calibrated the station with firmware 1.46? What values in the menu do you get?

[garyww]

Curious to know this too.

hi
anibody, do you have pin out of fan handle?
please post it

[cephyr]

hey @raihei thanks for sharing!

I also recieved an Kaleep rework station with the same chip
looking forward to mod mine too.
Which conversion PCB did you use?

@all is there someone which has one MK1841D3 available for sale?
I wanted to order this one https://oshpark.com/shared_projects/vLy9R74P but I have to order three boards minimum.

Are there any recommendations for the conversion board?


thanks in advance guys!

[wguibas]

If you give me your address I could send one out to you for just the shipping.  The shipping costs like $13.50 USD, at least thats what it was to bulgaria for a package.  Maybe just the board without the components could be sent in a regular Letter envelope for much cheaper.

Wayne

[cephyr]

If you give me your address I could send one out to you for just the shipping.  The shipping costs like $13.50 USD, at least thats what it was to bulgaria for a package.  Maybe just the board without the components could be sent in a regular Letter envelope for much cheaper.

Wayne

thank you very much for your fast reply, I would take the offer if I solve the problem with my Kaleep that is occuring right now
just had it opened to check the chip

after putting it back together, the fan spin down mechanism does not work anymore. I did not touch any wiring.
The funny thing is, if I unscrew the front panel with the pcb, so that the pcb is not grounded anymore, the fan spin down mechanism works again 

does anyone know how to troubleshoot this?

edit: by the way, it is just the fan that does not spin down anymore after going into standby, the microcontroller recognizes the reed switch triggering and stops heating
I will return the unit if no one knows an answer
don't get it why it worked before dissasembling int

bad luck... the first unit I've got (Uvistar brand) also had this issue

[madworm]

It might be a crack in the PCB that only shows when mounted. The fan spin down works by pulling the base of the big TO-220 transistor (TIP122 ?) to GND via a 2nd small transistor (TO-92). You mighty try a continuity tester and bending the board slightly.

Power unplugged of course!

[cephyr]

It might be a crack in the PCB that only shows when mounted. The fan spin down works by pulling the base of the big TO-220 transistor (TIP122 ?) to GND via a 2nd small transistor (TO-92). You mighty try a continuity tester and bending the board slightly.

Power unplugged of course!

hey, thanks for the answer
that's a good explanation haven't thought about that, just had bad wiring in mind because of all the horror reports about this station

I will try to return it as long as I am able to, I like tinkering but would be nice to have a working unit to start with

[manianac]

I thank you Madworm for your firmware and board design, and wguibas for the MK1841D3 adapter board.

This is my first time making a board design, but I figure I'll attempt combining the BLDC detection board with the adapter board, and using smaller components.