Youyue 858D+ some reverse engineering + custom firmware

[HotAir]

Hello!
Got this one today, attached photos of PCB, as DGM said above, it's AVR based, and also it looks like have a different heater element.

I don't have a thermal couple to check how accurate is, but I had seen one comment in Aliexpress, some one says it's accurate, and as you can see it does not have a calibration.

Bought it for about 30€, I was able to take the Youyue 858D+ for the same money. So what do you think, it is have advantages to taking this instead of Youyue 858D+?
In case if it will be inaccurate, the custom firmware can be modified and loaded for it also, right?

[Gabse]

 Hey Guys,
I have a hacked 858D station an I am pretty happy with it. The station needs quite long to cool down if the fan speed limited (specially with the small nozzle), so I worked out a hack to make the speed switchable via Software. The Trick is to add a Transistor which shorts the potentiometer slider pin to ground. I used a BC547B, because I had it around, but any NPN Transistor should work. The current through the Transistor and the potentiometer bias resistor is about 5mA Which are 125mW on the Resistor.



On the Microcontroller side I used the until now unused PB3 (MOSI) Pin, because it should be easy accessible on most adapter boards. It is switched on when the hot hand piece is put in the cradle and also in Fan Test mode to get a accurate reference. I also improved the Handpiece-not-in-cradle-mode, because I think this way it saves some time on startup. Software is available on my GitHub page and  will hopefully be merged to madworms Page.
Cheers,

[DGM]

Hello!
Got this one today, attached photos of PCB, as DGM said above, it's AVR based, and also it looks like have a different heater element.

I don't have a thermal couple to check how accurate is, but I had seen one comment in Aliexpress, some one says it's accurate, and as you can see it does not have a calibration.

Bought it for about 30€, I was able to take the Youyue 858D+ for the same money. So what do you think, it is have advantages to taking this instead of Youyue 858D+?
In case if it will be inaccurate, the custom firmware can be modified and loaded for it also, right?

I didn't notice that this variant had no cal pot.  I wonder what the tolerance stackup is with all the resistors in the TC amp.  Maybe it's not a terribly big deal, but I haven't gone back to the schematic to check ... or checked this board against other AVR 858D schematics.  The worst-case scenario would just require calibration in firmware.  I suppose I should start adding AVR-based 858D maps to the board index, shouldn't I? 

So long as it functions well, I don't know why you couldn't use the alternative firmware.  It might take some remapping of the IO pins, but that's simple enough.   I suppose the big advantage that you get with AVR versions in general is the ability to drop a new MCU in the thing.  All the 20-pin types (like the 858D06 board in the current Youyue) need an adapter board of some sort.

If you do decide to try the alternative firmware and care to share your pin mapping, I'll gladly add it to the index. 

Hey Guys,
I have a hacked 858D station an I am pretty happy with it. The station needs quite long to cool down if the fan speed limited (specially with the small nozzle), so I worked out a hack to make the speed switchable via Software. The Trick is to add a Transistor which shorts the potentiometer slider pin to ground. I used a BC547B, because I had it around, but any NPN Transistor should work. The current through the Transistor and the potentiometer bias resistor is about 5mA Which are 125mW on the Resistor.

On the Microcontroller side I used the until now unused PB3 (MOSI) Pin, because it should be easy accessible on most adapter boards. It is switched on when the hot hand piece is put in the cradle and also in Fan Test mode to get a accurate reference. I also improved the Handpiece-not-in-cradle-mode, because I think this way it saves some time on startup. Software is available on my GitHub page and  will hopefully be merged to madworms Page.
Cheers,

I'd thought about that too, but I was kind of thinking that it could just be done in hardware.  I kind of figured it would suffice to pull the wiper down whenever the optotriac drive was inactive.  The only issue would be that you'd need some sort of delay to keep the mod inactive during normal heater switching operation.  I suppose a diode, cap, mosfet and a resistor would suffice.  If overshoot causes a long enough off-time to trigger the mod, it would likely only improve overall settling time. 

Of course, my entire approach would be problematic if you wanted to implement a blower-only mode with controllable speed.  Control through firmware is ultimately more flexible.

[HotAir]

Hm, in the Chinese manual which came with it, there is mention about temperature calibration(photo attached), here what I translated with google translate

"1, in the welding state, measure the actual temperature value, and record
2. In the welding state, the colleague presses the “▲” and “▼” keys to display “CAL”, when the release shows three small dots below the displayed value, Immediately enter the measured temperature (performed within three seconds). After the correct input, press the "▲" and "▼" keys simultaneously to display the "CAL" temperature calibration."

I have tried this method, however it does not work, strange...  I will try to ask other peoples in youtube, if their station can be calibrated, so to understand, if all those models can't be calibrated or just mine have an issue.

Few days ago ordered a thermometer with thermocouple, in few weeks it should arrive, then I'll test how accurate is that 858D

[Gabse]

I'd thought about that too, but I was kind of thinking that it could just be done in hardware.  I kind of figured it would suffice to pull the wiper down whenever the optotriac drive was inactive.

You could use the reed switch signal to switch the transistor every time the heater is in the cradle. That should work too, the only downsides are, it doesn’t work in Fan test mode, and if the heater is switched on all the time due to a broken TRIAC.

[DGM]

You could use the reed switch signal to switch the transistor every time the heater is in the cradle. That should work too, the only downsides are, it doesn’t work in Fan test mode, and if the heater is switched on all the time due to a broken TRIAC.

Oh, the reed switch.. /me facepalms
but really, not much protects against the inevitable stuck triac in these designs.

From my experience incinerating ebay SSR's and BTA26-800's by the dozen, I kind of learned to regard chinese triacs as a pending failure.

[HotAir]

I asked on youtube some peoples with same station, they said the calibration on their station is also does not working.

However, today I received my thermometer with thermocouple, did some quick tests, and found out that when I hold the thermocouple very close to the nozzle, almost inside, then the temperature is very accurate, like about 0 - 10 °C difference.

[DGM]

As far as i'm concerned, that's good news. 

The offset between the internal thermocouple and an external thermocouple is going to vary with distance, fan speed, and nozzle size.  Trying to cal for somewhere significantly beyond the end of the nozzle is going to be fairly pointless unless you never change the nozzle or fan speed.

[fordson]

Hi forum ,


I also have the HD 858d v1.0 mainboard with the unlabeled processor.

I tried to understand all info given in this tread , but i am i kind of lost ...............( mus tbe age ).

Is there already an adapterboard available which has been tested by someone ??  ( i have downloaded the eagle files already )
What is the result of this ?? , is it working with the custom firmware ?? ( also downloaded ) .


any help highly appreciated .




fordson

[bwack]

fordson, at least the HD 858d v1.0 board is in the index two pages back in this thread.

[fordson]

Yep , i have already downloaded all files i could find related to the HD858D v 1.0 .

But...................is there already someone out there who has managed to get it modded and working .

unfortunately i am a bit rusty in reverse-engineering 






As aliexpress is selling them by the thousands ...................

[DGM]

I only made the adapter layouts, but I do not have the boards to test them on.  You can always try to contact one of the members who have the Hyiko 858D's and ask them if they've pursued the mod.  IIRC, Miwer had expressed interest at least. 

https://www.eevblog.com/forum/reviews/youyue-858d-some-reverse-engineering-custom-firmware/msg1317403/#msg1317403
https://www.eevblog.com/forum/reviews/youyue-858d-some-reverse-engineering-custom-firmware/msg1328274/#msg1328274
https://www.eevblog.com/forum/reviews/youyue-858d-some-reverse-engineering-custom-firmware/msg1364083/#msg1364083
these links are in the reference index (I added yours)

If you are comfortable with making the adapter and programming the AVR, tailoring and debugging isn't that much more..
Sanity check the layout before you make the adapter.   Go over your board and make sure that the pin map in the index and eagle files matches what you see.
You'll also need the DMM to measure the voltage on the ADC so that you can calculate the ADC scaling for the TC.
I mentioned this in a post a few pages back, or there's a sheet in the index spreadsheet for calculating the scaling factors.

If you're worried about the risks associated with the heater control, just disconnect the heater from the board until you're sure the code appears to be working. 
You could probably even use a heat source (lighter or something) on the TC to demonstrate that the ADC is working and that the firmware turns the heater off.
That way you won't have to worry about roasting the heater if there's an issue with the code.
I don't think there's any checks in the code that would make such a test problematic (someone can correct me)

[Miwer]

You'll also need the DMM to measure the voltage on the ADC so that you can calculate the ADC scaling for the TC.
I mentioned this in a post a few pages back, or there's a sheet in the index spreadsheet for calculating the scaling factors.

Just adding a lille note on this.
I did actually make an adapter board for the Hylko model, but the temperature afterwards was all wrong of course. I wanted to use the firmware without modifications, but that require that I match the ADC input voltage range to the original adapter, and it was a bit harder to tune in, than I anticipated.

The problem with the Hylko model and the 858D-1.0 board is, that the unlabelled chip has no dedicated input for ADC reference voltage. If the chip is indeed a Zilog S3F94C8 (or equivalent chip), then the ADC reference voltage is fixed on VCC (so no need to measure it).

However, VCC is all over the shop, since this clone is so poorly designed. It's very hard to tune the temperature properly. I'm seeing VCC voltage drops and noise, whenever the hand piece fan is running, so I suspect the transformer is simply not big enough to handle the load, which is probably why the designers choose to put the IC after a diode with another capacitor, causing the chip to run at 4.3V instead of 5V. Not that it helps, since the caps are shitty quality anyway. I tried swapping some of them, and got a more stable power rail, but could still not adjust the temperature properly, and I have just not worked on it since last time I posted.
I probably should have another look at it, since at the moment it's just sitting on the bench.

/Miwer

[borngborn]

So i unluckily got a youde858dv4 should i order a whole new station or order a new pcb

Sent from my SM-N950U using Tapatalk

[Tracker]

Hi Guys,
I'm a bit late to this party but hoping to catch up 

I ordered my 858D before realizing this thread existed.
Unfortunately I have ended up with a Hylko model, it was cheapest on fleabay so perhaps that's a clue.

Its got the V1.0 board, just like the images posted by fordson above.

Alternatives I can see on the UK Fleebay are these:

eBay auction: #283105542186 TAIKO with additional sockets/plugs front and rear.

eBay auction: #253281029627 ANSAI with a rear mains socket and looks like a 1/4" jack at the rear , no idea whats that for.

eBay auction: #163017135315 WER

Is there point is trying one of these for a more suitable control board?

Thanks.
Tracker

[Tracker]

Just took delivery of mine today.

https://www.ebay.co.uk/itm/858D-220V-SMD-Soldering-Desoldering-Station-Hot-Air-Rework-Gun-Tool-3-Nozzles/301966004104?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

Had a quick look inside and it seems pretty well made. I took a pic of the board

Looks like the same one I have.

nc94

Same board here.
I did some front pot calibration with a K-type Thermocouple and found the overshoot was not too bad.
Also found the results were more stable after a burn-in period, i.e. ran it at 400 for a 5 minutes, then perform the pot calibration.
Overshoot was about 5 to 10 degrees when heating upwards.


Low air flow (2 on dial)
100 set = avg 103 measured
200 set= avg 202 measured
300 set = avg 298 measured
400 set = avg 402 measured

Mid air flow (4.5 on dial) :
100 set = avg 97 measured
200 set= avg 194 measured
300 set = avg 298 measured , pot calibration point
400 set = avg 425 measured

High airflow (7 on dial)
100 set = avg 99 measured
200 set= avg 206 measured
300 set = avg 315 measured
400 set = avg 440 measured , largest error measured


Note, tests performed ramping the temp upwards, i.e. 100, 200 300 etc. The reverse (400, 300, 200 etc) produced odd unstable results, probably due to the heater handle having thermal mass and holding heat.

So not too bad, better than I was expecting.
PS, nosel was the middle one, about 8mm wide.

Tracker

[ncx94]

Just took delivery of mine today.

https://www.ebay.co.uk/itm/858D-220V-SMD-Soldering-Desoldering-Station-Hot-Air-Rework-Gun-Tool-3-Nozzles/301966004104?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

Had a quick look inside and it seems pretty well made. I took a pic of the board

Looks like the same one I have.

nc94

Same board here.
I did some front pot calibration with a K-type Thermocouple and found the overshoot was not too bad.
Also found the results were more stable after a burn-in period, i.e. ran it at 400 for a 5 minutes, then perform the pot calibration.
Overshoot was about 5 to 10 degrees when heating upwards.


Low air flow (2 on dial)
100 set = avg 103 measured
200 set= avg 202 measured
300 set = avg 298 measured
400 set = avg 402 measured

Mid air flow (4.5 on dial) :
100 set = avg 97 measured
200 set= avg 194 measured
300 set = avg 298 measured , pot calibration point
400 set = avg 425 measured

High airflow (7 on dial)
100 set = avg 99 measured
200 set= avg 206 measured
300 set = avg 315 measured
400 set = avg 440 measured , largest error measured


Note, tests performed ramping the temp upwards, i.e. 100, 200 300 etc. The reverse (400, 300, 200 etc) produced odd unstable results, probably due to the heater handle having thermal mass and holding heat.

So not too bad, better than I was expecting.
PS, nosel was the middle one, about 8mm wide.

Tracker

I found that this unit is pretty good after all. It has a lot of the safety features working in it's stock form

nc94

[Tracker]

Agreed, the 'HYLKO' I received had good grounding to the heat shroud via a central PCB standoff.
I didn't need to make any changes other than to add an IEC socket at the rear for convenience since most of my bench uses IEC power cables.

cheers
Tracker

 

[borngborn]

So i threw away the youdev4 and got the Youyue 858d06 is their a board made for this one

Sent from my SM-N950U using Tapatalk

[Fleetz]

Hello!
Got this one today, attached photos of PCB, as DGM said above, it's AVR based, and also it looks like have a different heater element.

I don't have a thermal couple to check how accurate is, but I had seen one comment in Aliexpress, some one says it's accurate, and as you can see it does not have a calibration.

Bought it for about 30€, I was able to take the Youyue 858D+ for the same money. So what do you think, it is have advantages to taking this instead of Youyue 858D+?
In case if it will be inaccurate, the custom firmware can be modified and loaded for it also, right?

What make and model is the one you bought? Did you get this from Aliexpress?

[Fleetz]

Hello!
Got this one today, attached photos of PCB, as DGM said above, it's AVR based, and also it looks like have a different heater element.

I don't have a thermal couple to check how accurate is, but I had seen one comment in Aliexpress, some one says it's accurate, and as you can see it does not have a calibration.

Bought it for about 30€, I was able to take the Youyue 858D+ for the same money. So what do you think, it is have advantages to taking this instead of Youyue 858D+?
In case if it will be inaccurate, the custom firmware can be modified and loaded for it also, right?

Anyone know what make/model this is that member HotAir is referring to?

[Fleetz]

Hello!
Got this one today, attached photos of PCB, as DGM said above, it's AVR based, and also it looks like have a different heater element.

I don't have a thermal couple to check how accurate is, but I had seen one comment in Aliexpress, some one says it's accurate, and as you can see it does not have a calibration.

Bought it for about 30€, I was able to take the Youyue 858D+ for the same money. So what do you think, it is have advantages to taking this instead of Youyue 858D+?
In case if it will be inaccurate, the custom firmware can be modified and loaded for it also, right?

Are these photos of a Youyue 858D+ ?

How have you found it’s performance?

Which supplier did you purchase from?

Cheers...

[Fleetz]

Hello!
Got this one today, attached photos of PCB, as DGM said above, it's AVR based, and also it looks like have a different heater element.

I don't have a thermal couple to check how accurate is, but I had seen one comment in Aliexpress, some one says it's accurate, and as you can see it does not have a calibration.

Bought it for about 30€, I was able to take the Youyue 858D+ for the same money. So what do you think, it is have advantages to taking this instead of Youyue 858D+?
In case if it will be inaccurate, the custom firmware can be modified and loaded for it also, right?

Are these photos of a Youyue 858D+ ?

How have you found it’s performance?

Which supplier did you purchase from?

Cheers...

I reached out and asked a couple Aliexpress suppliers of YouYue 858D+ what version boards/MCU they were supplying. Basically was told they have no control it could be either the single sided or double side and could be Atmel or Samsung MCU. “If it matters to you please don’t buy”

Pig in a poke...

[bitseeker]

“If it matters to you please don’t buy”

That's got to be the best answer (or caveat emptor) I've heard from an AliExpress or eBay vendor. Since most sell a cornucopia of products, they usually don't know the specifics of any particular one (surprisingly this one apparently knows a bit) and are at the mercy of whatever gets shipped to them or that they happen to pick up from the market at the time.

[Fleetz]

Is there a differences in features and or functions between the 858D and 858D+ models?