Thank you, it solved my problem
Hi @aceindy,
First of all thanks for your amazing work here, I really appreciate it a lot! 
I read more or less the entire thread and tried multiple setups but didn’t hat any luck yet.
My board looks pretty similar to the one @nvschilleman posted but I don’t have the USB daughter board. Instead there is a separate PCB where some users have their Wifi USB board. On there are connectors for an external switch and the wired controller which I both tested without success.
I also soldered on a connector to the CN2 port on the display port but couldn’t get it working.
Without the board on CN3 the IR remote isn’t working.
Do you have any more ideas?
Here are the pictures.
The unit is a Remko MXW 354.
Thanks for your help!
UPDATE:
This manual shows the exact same setup as for mine, it looks like the WiFi board needs to be connected at the CM3 port where the other adapter board is connected in my case.
According to that my best bet is to connect via the CCM Comm.Bus / Wired Controller port?
Doesn’t looks familiar to me, sorry.
Maybe the optional wifi board looks like this?
(from an earlier post)
And as you mentioned, it should be connected to CN3 (as where your comm board is plugged in)
Thanks for the quick reply. I’ll try to find one of the wifi boards on ebay or aliexpress to see if it’s compatible. Otherwise I’ll try to find a wired controller and reverse engineer the protocol 
I use the same as from this post, wifi directly plugged into cn3:
I do notice however that my CN3 has 4 pins and yours uses 5 (and so does the wifi board from previous post🤔)
But i really don’t know if that wifi board goes with your ac….
Units with a 5 pin CN3 typically use a separate board which contains the uart bus thus the “USB” port. However, I have been told there are differences between a Wifi enabled indoor unit PCB and a non Wifi enabled one, which would mean just plugging in the PCB belonging to CN3 would not work.
Worth trying to imho
I looked at the board again and noticed that the wired controller is also labeled as 485 Wire-Controller. I guess this means the controller board somehow uses RS485 to communicate to the wired controller.
Does anyone know any details regarding the RS485/Modbus interface?
If it is a midea clone, it probably uses the same protocol…
Some one else posted this diagram, looks very similar to yours
it mentions both CN2 and CN3 on the display board (and your diagram only mentions CN3)
I also noted that that 485 board should appearantly be connected to CN2, but in your case it is actually connected to CN3, while CN2 is not installed??
It wouldn’t surprise me if you can just replace that 485 board with a wifi controller…
(how are CN2 and CN3 wired on the pcb? parallel ??)
The ID on the top right matches “16022000003662” but it’s slightly different.
CN2 and CN3 use different pinouts CN2 starts with VCC and CN3 starts with GND so there is a difference. According to the fact that the IR remote doesn’t work if its disconnected I guess I have an older version.
The newer ones probably have an embedded controller.
Thanks! You mentioned that you might be able to source the components directly from the vendor.
Do you think it’s possible to get one of these USB boards separately?
or
Would be worth a try I guess
Since “wifi module” is mentioned on the wiring diagram I think it could actually work.
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Hi, this device was recently mounted in our home and it does not want to cooperate.
I replaced the dongle with an ESP-01S connected through a voltage converter and logic level shifter to the board. I see RX responses sometimes, but timeouts are always reported and the HA entity is not updating/controlling anything. Did they change protocol on newer devices? Or do I have to register in the cloud first to activate the interface?
No need for cloud.
I too am currently working on a 2nd AC with osk-105, but i’m not finished yet…
I’ve seen some issues reported on Telegram, but they vague reports.
My 1st AC is an Olimpia Splendid Nexya 9 with osk103, the new one an Olimpia Splendid Nexya
10 with OSK105.
What is you brand/type AC @rp3tya ?
Will get back to you when i have more info, maybe one or two weeks (don’t have much time, sorry)
Midea air conditioner, internal unit is MA2-18NXD0-I (Midea MA2-18NXD0-I inverter air conditioner | Midea wall-mounted air conditioners | Midea air conditioning systems | Midea.bg) and came with an SK105 dongle.
This is the first airco I’m trying to link to HA, otherwise I have some experience with ESPHome. Not much time I can dedicate to tinkering nowadays, but let me know if I can contribute…
You could join Telegram (this is where support from devs is a available)
You could post this log page there
Hello Guys,
I have a Midea MKG-V250B “fan coil” unit and I’m wondering if it is able to controlled with the ESP based wifi unit. It doesn’t have a USB connector, but the same colored 5 wire cable that is used for the USB PCB from a previous post.
How can I check it (without purchasing the USB PCB)?
For those who are talking about using modbus for midea’s heatpump. I am currently a student of electrical engineering and for my final project i’m working on making a controller for midea’s heatpump.
It’s currently still in development but i can obtain almost all information from it and even set a desired mode, change temperatures etc. I currently cannot release whole project as it’s kinda property of my university but will try to get an agreement to release it when i finnish it. So basicly if anyone needs any information i might be able to help. Modbus connects to control unit (lcd display), they added screw in terminals for that… and it can be used with cheap MAX485 module from aliexpress xy-017.
https://shop.systemair.com/upload/assets/OPERATION_MANUAL_EN_20210407_153552287.PDF?f39b69c9 this was a big help as manual i got with heatpump did not include MODBUS mapping table and not even where to connect it. I have the same unit as this this one is branded as systemair but some of the mapping table is the same
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@aceindy I’ve got universal-iot-dongle up and working - bought via Tindie, my unit is KMTI-48N8-A3 this is 14 kW Midea duct channel unit and I’ve got wall remote control with follow me - KJR-29B but follow me often goes off, so I’m trying to utlilize home assistant and iot-dongle to provide temperature.
Above is my ceiling wifi unit that came with midea - currently dongle is plugged there and all works fine but I lack follow me option - can you advise if REC1 next to USB female connector is the iR I’m looking for and I need to connect that REC1 signal line to iR - pad on dongle?
hello guys. thanks for the guides, I got my AC working with esphome and homeasistant , but I want to know if there is a way for the ac to remember the settings and not turn on at eco mode with fan in auto everytime.
Can I do that in any part of the esphome code?
thanks I really appreciatte the help
As far as I can see the REC1 next to USB female connector is the iR you’re looking for, that is, i can’t see any other iR components🤔.
So yes, you need to connect that REC1 signal line to iR - pad on dongle!
Only the pin layout might be a bit of a puzzle…
PS, i don’t have the iot dongle, and not using the follow-me function either, so this is all the help i can give on this subject
That is not normal behavior to me, my ac turns on at the same setting it turned off…
I think i’ve seen someone reported something similar, but this was related to the unit using an OSK105 wifi dongle instead of the OSK103.
Devs are looking into what exactly changed with OSk105 (if anything changed at all…)