Almost done, now waiting to arrive second ESP32 to test between two of them (one acting as dummy AC) instead of immediately “going live” 
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Hello,
I’m investigating my issue … For those who have a ESP that works, does it crash when it is not connected to the Fuji remote ??
Here are my logs , it does bootloop until running in SAFEMODE (not in the log to keep this post ‘short’)
Watchdog is expiring .
[19:38:28]ets Jun 8 2016 00:22:57
[19:38:28]
[19:38:28]rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
[19:38:28]configsip: 188777542, SPIWP:0xee
[19:38:28]clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
[19:38:28]mode:DIO, clock div:2
[19:38:28]load:0x3fff0030,len:4688
[19:38:28]load:0x40078000,len:15504
[19:38:28]load:0x40080400,len:4
[19:38:28]load:0x40080404,len:3196
[19:38:28]entry 0x400805a4
[19:38:29]E (452) esp_core_dump_flash: No cof"յ��partition found!
[19:38:29]E (453) esp_core_dump_flash: No core dump partition found!
[19:38:29][I][logger:169]: Log initialized
[19:38:29][C][safe_mode:082]: There have been 0 suspected unsuccessful boot attempts
[19:38:29][D][esp32.preferences:142]: Writing 1 items: 0 cached, 1 written, 0 failed
[19:38:29][I][app:049]: Running through setup()
[19:38:29][D][fuji:028]: Fuji initialized
[19:38:29][D][fuji:035]: starting task
[19:38:29][C][wifi:048]: Running setup
[19:38:29][C][wifi:061]: Starting
[19:38:29][C][wifi:061]: Local MAC: F0:24:F9:BA:E2:14
[19:38:29][D][wifi:495]: Starting scan
[19:38:29][W][component:279]: wifi set Warning flag: scanning for networks
[19:38:29][D][fuji:135]: ctrl temp 16 vs my temp -2147483648
[19:38:29][D][fujitsu:155]: ctrl fan mode 2 vs my fan mode 255
[19:38:29][D][fuji:192]: publishing state
[19:38:29][D][climate:396]: 'Fujitsu' - Sending state:
[19:38:29][D][climate:399]: Mode: OFF
[19:38:29][D][climate:404]: Fan Mode: AUTO
[19:38:29][D][climate:419]: Current Temperature: 16.00°C
[19:38:29][D][climate:425]: Target Temperature: 16.00°C
[19:38:34]E (10972) task_wdt: Task watchdog got triggered. The following tasks/users did not reset the watchdog in time:
[19:38:34]E (10972) task_wdt: - loopTask (CPU 1)
[19:38:34]E (10972) task_wdt: Tasks currently running:
[19:38:34]E (10972) task_wdt: CPU 0: IDLE0
[19:38:34]E (10972) task_wdt: CPU 1: FujiTask
[19:38:34]E (10972) task_wdt: Aborting.
[19:38:34]E (10972) task_wdt: Print CPU 1 backtrace
[19:38:34]
Yesterday I received second ESP32, and unfortunately it does not receive any UART data with the exact same code in it. I found out that new ESP is newer version (ESP32-D0WD-V3) than my first one (ESP32-D0WDQ6). Digging whats wrong
Not fully tested, but proof of concept works, so I will share the project:
Hi Benas, Can you give more detail on what your POC is doing? I’ve got 2 types of households with Fujitsu AC units. One unit has 3 wires going to the older style Wall Controler, My other has just 2 wires connecting to the wall unit. I’ve successfully been able to flash my Atom M5 and have been able to configure the Wifi etc… The circuit I have however looks like it is for the 3 wire wall controllers. These seem to have been replaced by a simpler 2 wire wall controller in newer buildings… so what do we do with these newer apartments/units? Is there anything I can do to help further this work? I can offer up a unit with the 2 wire setup but will need to be guided through how to trace/reverse engineer the newer 2 wire protocol/setup. @Benas will your POC work with the 2 wire controllers? What can I do to help progress this?
It is direct replacement for UTY-TFSXW1 wifi module. It plugs to indoor unit socket
I dont know about wall controllers. Maybe they use different connection. I dont think it would work with 2 wires only, because there are 2 wires for uart + 2 for power
What is your ac model? Maybe it supports such module.
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Great start! Thank you for that. Have you considered building it as a esphome component?
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Yes, I think I will make esphome integration also, but first i want to have fully working code with mqtt discovery
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Hi everyone,
I have a Fujitsu ARYG24LMLA ducted air conditioner. The wall controller is connected via a 3-wire interface.
I’m wondering if it’s possible to integrate this unit with Home Assistant using an ESP32. Has anyone done this with a similar setup?
Thanks in advance!
Yes, several users in this thread have reported success using this controller
Hey guys,
I finally got around to building 10 of the FSOV designed PCB boards, sorry for taking forever…life gets busy with a newborn.
Anyways, I’ll provide an m5stack Atom Lite with ESPHome preloaded and a wiring harness. The wiring harness plugs into the Atom Lite and the other end can be either wire leads or a JST XAF 5 position 2.5mm pitch plug which seems to be the typical connector for the control board directly on the indoor unit. I can’t find the threads where I identified this connector but this is what fits my unit. With my setup, the Atom Lite is powered by the indoor unit connection and doesn’t need the USB-C connector.
Thinking about selling them for about $45 plus shipping costs to your location from the eastern US. Seems like USPS is the cheapest for this small of a package (~$15 most places) but may take a while if you’re on the other side of the world. However, feel free to use whatever speed shipping you want to pay for.
Let me know if you are interested and we can work on arranging delivery.
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PM sent. thanks!
PM sent thanks
Hi @ba114,
Your board is amazing!!!
I have a Fujitsu ARYG24LMLA ducted air conditioner. The wall controller is connected via a 3-wire interface. Please could you share with me the steps for manage my air conditioner in HA with a ESP32.
Thanks in advance,
Best regards,
Fran
Hi all,
Im going to get a try to this project. Please could you confirm the best version of ESP32?
There are at least 2 different version based on chipset:
ESP32 WROOM-32 TYPE-C CH340C
ESP32 WROOM-32 TYPE-C CP2102
I have this version ESP32 WROOM-32 TYPE-C CH340C but as I need to buy the rest of component I’d like to confirm if I need to buy a new ESP32.
Thanks in advance,
Fran
They should be the same, only usb-serial converter chip is different. I dont think you will notice a difference
Hello Omniflux - thank you again for your contributions and help!
Yesterday and today, I finally had the time to work this out. This may not be the best communication channel so let me know if there is a better way.
First of, I replaced the original integration for a single unit by yours using fujitsu-halcyon and it works flawlessly, I can even now control both directions of air flow. I also played with tzsp and can send traffic sniff to my server and capture with tcpdump. Thanks A TON for all your work. Have to admit I had to fight my esphome and few things until I realized I was not in esp32-idf mode but anyways…
Now, I’m trying to integrate my UTY-DMMGM unit and there I’m a bit stuck. I used the exact same esphome, a different ESP32 and the same breadboard as for the single unit. That way I just program a spare ESP32, replace the one of the breadboard and move the quick wires from one wall controller to the other.
Enabling logging debugs, I constantly see [UART_Event]: TX: 24 90 00 00 00 00 00 00. To my best judgement, I guess this is a “break” sent to the bus to say there is an extra controller. However, I never see anything back.
If I power cycle the branch boxes (the UTY-DMMGM is connected to one of the branch boxes, not to the outdoor unit), I seem to catch a (bad) RX:
[09:46:12][D][fujitsu_general::airstage::h::central_controller:178][UART_Event]: UART parity error [09:46:12][D][esphome::fujitsu_general_airstage_h_central_controller::controller:037][UART_Event]: RX: 3F 81 FB 3F 04 81 FB 3F [09:46:12][D][fujitsu_general::airstage::h::central_controller:140][UART_Event]: Discarded 1 bytes
Both wall units (so the UTY-DMMGM and one controller of one of the unit - used for temp sensor of that room) are showing the famous Err-12 code; until I disconnect the ESP32 and power cycle the branch box. Probing the ESP32 RX with an analog scope, I can see signal coming in.
I therefore disconnected the ESP32 TX pin to the MCP2025, to avoid disturbing the BUS and the debugs are continuously cycling with the following messages:
[10:19:34][D][fujitsu_general::airstage::h::central_controller:157][UART_Event]: UART break! [10:19:34][D][fujitsu_general::airstage::h::central_controller:178][UART_Event]: UART parity error [10:19:34][D][esphome::fujitsu_general_airstage_h_central_controller::controller:037][UART_Event]: RX: 02 02 02 00 04 81 FB 3F [10:19:34][D][fujitsu_general::airstage::h::central_controller:140][UART_Event]: Discarded 4 bytes [10:19:34][D][esphome::fujitsu_general_airstage_h_central_controller::controller:037][UART_Event]: RX: 30 B0 00 1D 00 A6 13 00 [10:19:35][D][esphome::fujitsu_general_airstage_h_central_controller::controller:037][UART_Event]: RX: 30 B0 00 1D 10 24 16 00 [10:19:35][D][esphome::fujitsu_general_airstage_h_central_controller::controller:037][UART_Event]: RX: 30 B1 00 1D 20 24 13 00 [10:19:35][D][esphome::fujitsu_general_airstage_h_central_controller::controller:037][UART_Event]: RX: 31 B1 00 60 30 A4 14 00 [10:19:35][D][esphome::fujitsu_general_airstage_h_central_controller::controller:037][UART_Event]: RX: 31 B1 00 60 40 24 13 00 [10:19:35][D][esphome::fujitsu_general_airstage_h_central_controller::controller:037][UART_Event]: RX: 31 B2 00 60 50 24 13 00 [10:19:36][D][esphome::fujitsu_general_airstage_h_central_controller::controller:037][UART_Event]: RX: 31 A4 00 60 30 A4 14 00 [10:19:36][D][esphome::fujitsu_general_airstage_h_central_controller::controller:037][UART_Event]: TX: 24 90 00 00 00 00 00 00
Not sure what else to do at this point on my end 
If you have any clues or advise, please let me know
Btw I’m on ESPHome 2025.5.0 - I don’t think it’s important but you won’t believe how many releases I tried before successfully compiling…
Best regards,
Pierre
Unlike the indoor unit controllers, only one central controller can be connected at a time, as far as I can tell - you have to disconnect the UTY-DMM?M controller to use an ESP controller.
I can see from your logs that the addressing is slightly different when talking to a branch box instead of the outdoor unit. I have decoded the addressing from your post, but we may need to capture some more packets to support transmitting changes. I will message you about it.
Thanks a lot - just let me know any data you may need.
If it helps decoding; here is how things are wired:
OU= MSAO45RIY8
Refrigerant goes to 2 branch boxes through a passive Y-splitter.
BB1: UTP-PYO3A it’s a 3-outputs branch box, connected to 3 IUs
BB2: UTP-PYO2A it’s a 2-outputs branch box, connected to 2 IUs
The main UTY-DMMUM is wired to BB1, if I’m not mistaking. (it’s hard to follow the mesh of wires but I can go get that double checked if you want me to).
When you power cycle the system, the UTY-DMMUM takes his sweet 20-30sec displaying loading before it’s operational.
Roger the eventually of having to disconnecting it; I btw now wired a new breadboard where the ESP32 Tx is disconnected so we can sniff without disturbing anything.
Hi @francisps78 ,
I have the same unit, but it still not work for me.
Git projects given in this topic has to be fixed, they do not work ‘as it’ because they are not up to date with last HA updates…
It is not hardware issue but software issues : bootloop, connexion to HA is not stable,…
Moreover, becareful with HA issue too, when you remove ESP device, do not create a new device with the same name because HA (ESP Home) will compile old file (cached file impossible to delete ??).
Good luck !