That’s actually really nice.
Looks like it’s meant to fit the 10pin usbasp cable. Though I don’t see the pinout listed, I would message the seller to be sure.
Nice that it uses a zero insertion force socket for the atmega.
Just FYI, I used this board (needs to be assembled first):
http://www.aliexpress.com/item/ATmega8-ATmega48-ATMEGA88-board-AVR-quality-DIY-kits-no-chips/32340363689.html
in conjunction with this (already assembled):
http://www.aliexpress.com/item/1LOT-New-USBASP-USBISP-AVR-Programmer-USB-ISP-USB-ASP-ATMEGA8-ATMEGA128-Support-Win7-64K/1973355805.html
The one above is basically a minimal configuration board - like you would set it up on a breadboard. The USBasp will power the chip when programming it (like it would on a breadboard). The USB-port/switch is only for powering the chip if no programmer is connected.
Later I also added a 6-pin ISP header to the backside of the station. Now I use this USBasp with a 6-pin connector:
http://www.aliexpress.com/item/1PCS-USBasp-H6-USB-ISP-5V-AVR-Programmer-USB-ATMEGA8-ATMEGA128-New-1PCS-6PIN-Wire-Support/2036401781.html
There is also this:
http://www.aliexpress.com/item/1PCS-10Pin-to-6Pin-Adapter-Board-for-AVRISP-MKII-USBASP-STK500-High-Quality-BTE13-006/2036402715.html
(I have one, but I never used it yet.)
I wonder how long it would take the items from Aliexpress to get to either the US or Germany. I’m US military living in Germany and I return home in ~30 days, and I would like for it to be there when I get there.
I might just order the real USB programmer and the other ZIF socket board as they both ship from Europe.
You’d be pushing your luck quite a bit with 30 days from China to Germany. And if the German customs should take an interest, all bets are off.
Better have it shipped to your US address right away.
Yes, unfortunately that’s the big downside of AliExpress. Sometimes it takes only a week, sometimes it takes six or even more.
This seems to be something similar:
http://www.ebay.de/itm/Programmer-AVR-USB-3-3V-5V-USBasp-Socket-Programming-ATMEL-ISP-/201437375292?hash=item2ee69a6b3c
I was thinking using this ZIF socket board:
http://www.ebay.com/itm/121701392480
with this programmer:
http://www.ebay.com/itm/321859828737
The USBASP one supports the developer a little. The cost is ~$29 with shipping to Germany, and the one neo2001 mentioned is 14 Euro with shipping, also to Germany. Cheaper, but no ZIF socket, but I also won’t be doing that much reprogramming. I could add one later or one of madworm’s OSH Park boards later. 
edit - Does this board here: Board on eBay come with a ATMega328? Google translate didn’t help.
I would go for the one with the ZIF-socket, also because it’s explicitly described as compatible with the ATmega168/ATmega328.
According to the description - yes (it’s mentioned two times that this one includes an ATmega328P-PU)
Well, vielen dank and many thanks to all for the help! I just ordered the one board that comes with a ATMega328 and the USBASP programmer.
…now all I need to do is actually order the Youyue 858D. 
Oy!
I’ve finally had the chance to have circuit boards made. It appears to work.
This one finally is able to detect a fan-stall based on the slight ripple in fan-current during commutation.
More images and details on my blog.
http://blog.spitzenpfeil.org/wordpress/2015/10/23/youyue-858d-hotair-station-bldc-fan-speed-mod/
Both circuit boards are available via oshpark:
Great news. I’ve been using the mod firmware and need to get this new board assembled ASAP. Thanks for sharing!
Keep an eye on your sellers location. In my experience, almost without fail, one week shipping from China has actually been shipped from HK via HK Post, China using China post on the other hand is pretty much without fail 2-3 weeks.
At the moment it seems not possible to buy the original YouYue in Germany (EU), most of the sellers have only a version labeled “Kaleep” without a detachable heater (at least no security risk with hot contacts).
But I was not able to find an answer, wether the Kaleep version is still based on the Atmel/ATMega. Anyone?
Someone on the EEVBlog has built an adapter board to fit an ATmega168/328 into those hot-air stations that are fitted with a Samsung chip. Might be of interest.
I don’t know if this is already considered as “working”, but I guess the creator of the board will get it working/calibrated at some point
As far as the “Kaleep” goes, someone with time & money might want to buy one, for science!
I’m the guy from the other forum with the samsung adapter board. The calibration was way off, the analog signal is a different scale then in the Youyue units. I guess they are using a different resistor/divider between the wand and the chip. I modded the firmware to divide the A0 by 1.9 and changed the temp offset to 30. It seems to be working well. Before the temp would max out about 250 when the display said 450+, now the unit can reach into the 400’s and at 200-250 degrees it’s correct once settled in.
temp_inst = (analogRead(A0)/1.9) + temp_offset_corr.value; // approx. temp in °C
In summary, you have to cut 2 traces, disconnecting the LED segments from the push button circuits (they are shared on the samsung). Solder 2 wires to the LED segment legs to connect them to the new board. Solder 1 more wire to the fan speed controller pin on the main board and connect it to a header pin on the adapter board. Mod the firmware with the division factor and make sure the calibration pot on the front of the unit is set to 560 Ohms.
Hi and welcome wguibas. Thanks for dropping in and sharing the info. Now to get you hooked onto flashlights. 
This looks interesting - a complete redesign it seems. Work in progress.
I just got my hands on a 110V Kaleep 858D and it has a MK1841D3 chip in it.
Amazon.com*sr_ph&sr=1”:Amazon.com*=sr_ph&sr=1
I should have a new adapter board for it in about a week.
Bugfix release V1.44 is out!
If you have any issues with the infamous rSt-error, please update. First tests have been very promising, even on chips previously deemed as defective.
Special versions for the Samsung chip-adapters etc. by “wguibas” will be released later.