Many thanks to the community! After reading a lot and realizing that the last feasible way to make this project work was through Omniflux Halcyon, I followed the steps described there — and it worked on the very first try!
Honestly, thank you so much. I haven’t needed to ask any questions so far, but I really appreciate the effort and dedication of everyone who contributes to this forum.
I was about to buy two IntesisBox units, so you’ve probably helped me save around €400 — truly grateful!
Hey Nathan,
I can’t PM you as well, but I’d be keen to take 3 of them off your hands once they arrive
I also can’t send a PM but would be keen to buy a board off you. Cheers
@nathansags I can’t DM either but which country?
There is a change in ESPHome 2025.10.0 that affects how data is received at lower baud rates - https://github.com/esphome/esphome/pull/8103.
If you are using the esphome-fujitsu-halcyon or esphome-fujitsu-dmmum components you will need to make an adjustment to your uart component to restore the old behavior.
uart:
rx_full_threshold: 120
I started to reverse engineer the UART protocol for Fujitsu Airstage units (the protocol used between the air handler and the official UTY-TFSXJ4 WiFi dongle). Since ha_airstage is working pretty great locally with the official dongle, I’m not sure I’ll continue building my own ESPHome integration, but I wanted to share what I learned in case anyone wants to pick up the trail.
The UART seems to be 9600 baud, 8 bit + 1 stop bit, no parity, inverted signal. Logic analyzer captures are in the captures dir. Everything else is a GPT5 vibe-coded interpreter for those captures (and at first glance the interpretation seems very sane!)
Looks the same protocol as i made an integration
That’s great news!
I tried briefly to hook up your project but wasn’t getting any communication from the air handler. Maybe something wrong with my level shifter setup. Interestingly for me I noticed that with the real WiFi unit one line is logic level 5V and the other is 3.3V. If I do any further investigation I’ll chime in on your thread.
I looked again to your captures, and possible, that I made my statement too early. Bytes sequence look a bit differently.
Can you upload at least one .sal file (for example turn off.sal)? Because I can not load these .sal.csv to salae app.
Done! I went ahead and committed them all to the repo.
Hola @nathansags no puedo enviarte privado
I have ready to use board with ESP32 (Dual core), anyone interest can PM me or visit my signature link.
Hey @nathansags I’ve been googling for the past year on how to “smart up” my ducted aircon. I’m interested in your device, I don’t supposed you have a guide on how to set the whole process up? I’ve found nothing in Aus other then Fujitsu Airway and Airtouch
Hey Mully,
Im happy to assist wherever I can, for myself i just flashed the GitHub - Omniflux/esphome-fujitsu-halcyon: Fujitsu AirStage-H (Halcyon) component for ESPHome firmware to my board using ESPhome.
Once the firmware was on the board, I turned of the isolator switch for the ac unit and connected my pcb via a three core cable to the terminals on the indoor unit.
Once that was complete I then re-energise the ac system and check for any errors on the OEM control panel.
Then in Home Assistant you should be able to add the pcb into you system through ESPhome Builder and have full control.
I can send through when required a copy of the yaml I have been using for more than 12 months without issue.
Regards,
Nathan
thanks @nathansags I’ll take any assistance I can get please, I tried to PM you but I’m new to this forum and haven’t figured that out. Do you still have any of those boards for sale?
Hey @nathansags just checking in on how I can get one of those units off you? Or anyone really. I’m just after a unit.
I live in NSW Australia if that makes it easier
I recently bought the controller board from @nathansags and have tried to get it working on my system. However I have been unable to get it to work.
My indoor unit is the Fujitsu ARTC60LCTU and the outdoor unit is the AOTD60LATT. The controller is the UTY-RNN*M.
When I connect the board to the controller, it comes up with an error CO 1C on the main controller.
The dipswitches on the controller are all in the off position which means it is configured for dual controllers. The board is set as the slave controller.
The logfile shows many UART parity errors.
Here’s the first section of the logfile:
INFO ESPHome 2025.11.1
INFO Reading configuration /config/esphome/airco.yaml...
INFO Starting log output from airco.local using esphome API
WARNING Can't connect to ESPHome API for airco.local: Timeout while resolving IP address for ['airco.local'] (ResolveTimeoutAPIError)
INFO Trying to connect to airco.local in the background
INFO Successfully connected to airco @ 192.168.10.153 in 0.004s
INFO Successful handshake with airco @ 192.168.10.153 in 0.110s
[19:40:32.649][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:32.663][I][app:190]: ESPHome version 2025.11.1 compiled on Nov 26 2025, 23:58:41
[19:40:32.663][C][logger:261]: Logger:
[19:40:32.663][C][logger:261]: Max Level: DEBUG
[19:40:32.663][C][logger:261]: Initial Level: DEBUG
[19:40:32.664][C][logger:267]: Log Baud Rate: 115200
[19:40:32.664][C][logger:267]: Hardware UART: USB_SERIAL_JTAG
[19:40:32.664][C][logger:274]: Task Log Buffer Size: 768
[19:40:32.667][C][uart.idf:214]: UART Bus 0:
[19:40:32.672][C][uart.idf:215]: TX Pin: GPIO21
[19:40:32.677][C][uart.idf:216]: RX Pin: GPIO20
[19:40:32.677][C][uart.idf:219]: RX Buffer Size: 256
[19:40:32.677][C][uart.idf:219]: RX Full Threshold: 120
[19:40:32.677][C][uart.idf:219]: RX Timeout: 2
[19:40:32.678][C][uart.idf:225]: Baud Rate: 500 baud
[19:40:32.678][C][uart.idf:225]: Data Bits: 8
[19:40:32.678][C][uart.idf:225]: Parity: EVEN
[19:40:32.678][C][uart.idf:225]: Stop bits: 1
[19:40:32.696][C][uptime.sensor:017]: Uptime Sensor 'Uptime'
[19:40:32.696][C][uptime.sensor:017]: State Class: 'total_increasing'
[19:40:32.696][C][uptime.sensor:017]: Unit of Measurement: 's'
[19:40:32.696][C][uptime.sensor:017]: Accuracy Decimals: 0
[19:40:32.698][C][uptime.sensor:027]: Device Class: 'duration'
[19:40:32.701][C][uptime.sensor:031]: Icon: 'mdi:timer-outline'
[19:40:32.703][C][uptime.sensor:033]: Type: Seconds
[19:40:32.707][C][switch.gpio:092]: GPIO Switch 'Wifi_LED'
[19:40:32.707][C][switch.gpio:092]: Restore Mode: always OFF
[19:40:32.709][C][switch.gpio:029]: Pin: GPIO10
[19:40:32.723][C][esphome::fujitsu_general_airstage_h_controller:106]: FujitsuHalcyonController 'Airco'
[19:40:32.725][C][esphome::fujitsu_general_airstage_h_controller:107]: Controller Address: 1 (Secondary)
[19:40:32.728][C][esphome::fujitsu_general_airstage_h_controller:108]: Remote Temperature Controller Address: 0 (Primary)
[19:40:32.732][C][esphome::fujitsu_general_airstage_h_controller:017]: Remote Temperature Controller Sensor 'Remote Temperature Sensor'
[19:40:32.732][C][esphome::fujitsu_general_airstage_h_controller:017]: State Class: 'measurement'
[19:40:32.732][C][esphome::fujitsu_general_airstage_h_controller:017]: Unit of Measurement: '°C'
[19:40:32.732][C][esphome::fujitsu_general_airstage_h_controller:017]: Accuracy Decimals: 0
[19:40:32.735][C][esphome::fujitsu_general_airstage_h_controller:027]: Device Class: 'temperature'
[19:40:32.737][C][esphome::fujitsu_general_airstage_h_controller:112]: Ignore Lock: NO
[19:40:32.741][C][esphome::fujitsu_general_airstage_h_controller:113]: Standby Mode: NORMAL
[19:40:32.743][C][esphome::fujitsu_general_airstage_h_controller:698]: ClimateTraits:
[19:40:32.747][C][esphome::fujitsu_general_airstage_h_controller:699]: Visual settings:
[19:40:32.747][C][esphome::fujitsu_general_airstage_h_controller:699]: - Min temperature: 16.0
[19:40:32.747][C][esphome::fujitsu_general_airstage_h_controller:699]: - Max temperature: 30.0
[19:40:32.747][C][esphome::fujitsu_general_airstage_h_controller:699]: - Temperature step:
[19:40:32.747][C][esphome::fujitsu_general_airstage_h_controller:699]: Target: 1.0
[19:40:32.750][C][esphome::fujitsu_general_airstage_h_controller:734]: Supported modes:
[19:40:32.752][C][esphome::fujitsu_general_airstage_h_controller:736]: - OFF
[19:40:32.755][C][esphome::fujitsu_general_airstage_h_controller:736]: - HEAT_COOL
[19:40:32.759][C][esphome::fujitsu_general_airstage_h_controller:736]: - COOL
[19:40:32.761][C][esphome::fujitsu_general_airstage_h_controller:736]: - HEAT
[19:40:32.764][C][esphome::fujitsu_general_airstage_h_controller:736]: - FAN_ONLY
[19:40:32.767][C][esphome::fujitsu_general_airstage_h_controller:739]: Supported fan modes:
[19:40:32.775][C][esphome::fujitsu_general_airstage_h_controller:741]: - AUTO
[19:40:32.775][C][esphome::fujitsu_general_airstage_h_controller:741]: - LOW
[19:40:32.775][C][esphome::fujitsu_general_airstage_h_controller:741]: - MEDIUM
[19:40:32.776][C][esphome::fujitsu_general_airstage_h_controller:741]: - QUIET
[19:40:32.779][C][esphome::fujitsu_general_airstage_h_controller:749]: Supported presets:
[19:40:32.783][C][esphome::fujitsu_general_airstage_h_controller:751]: - NONE
[19:40:32.785][C][esphome::fujitsu_general_airstage_h_controller:751]: - ECO
[19:40:32.788][C][esphome::fujitsu_general_airstage_h_controller:759]: Supported swing modes:
[19:40:32.791][C][esphome::fujitsu_general_airstage_h_controller:761]: - OFF
[19:40:32.794][C][esphome::fujitsu_general_airstage_h_controller:761]: - VERTICAL
[19:40:32.799][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:32.814][C][captive_portal:122]: Captive Portal:
[19:40:32.821][C][wifi:1062]: WiFi:
[19:40:32.821][C][wifi:1062]: Connected: YES
[19:40:32.826][C][wifi:827]: Local MAC: 7C:DF:A1:B3:8B:E0
[19:40:32.828][C][wifi:834]: IP Address: 192.168.10.153
[19:40:32.832][C][wifi:838]: SSID: 'ar0'[redacted]
[19:40:32.832][C][wifi:838]: BSSID: 90:4C:81:77:AC:61[redacted]
[19:40:32.832][C][wifi:838]: Hostname: 'airco'
[19:40:32.832][C][wifi:838]: Signal strength: -44 dB ▂▄▆█
[19:40:32.832][C][wifi:838]: Channel: 1
[19:40:32.832][C][wifi:838]: Subnet: 255.255.255.0
[19:40:32.832][C][wifi:838]: Gateway: 192.168.10.251
[19:40:32.832][C][wifi:838]: DNS1: 192.168.10.72
[19:40:32.832][C][wifi:838]: DNS2: 192.168.10.73
[19:40:32.834][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:32.838][C][web_server:326]: Web Server:
[19:40:32.838][C][web_server:326]: Address: airco.local:80
[19:40:32.854][C][esphome.ota:093]: Over-The-Air updates:
[19:40:32.854][C][esphome.ota:093]: Address: airco.local:3232
[19:40:32.854][C][esphome.ota:093]: Version: 2
[19:40:32.857][C][esphome.ota:100]: Password configured
[19:40:32.860][C][safe_mode:018]: Safe Mode:
[19:40:32.860][C][safe_mode:018]: Successful after: 60s
[19:40:32.860][C][safe_mode:018]: Invoke after: 10 attempts
[19:40:32.860][C][safe_mode:018]: Duration: 300s
[19:40:32.877][C][web_server.ota:241]: Web Server OTA
[19:40:32.879][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:32.885][C][api:223]: Server:
[19:40:32.885][C][api:223]: Address: airco.local:6053
[19:40:32.885][C][api:223]: Listen backlog: 4
[19:40:32.885][C][api:223]: Max connections: 8
[19:40:32.885][C][api:230]: Noise encryption: YES
[19:40:32.898][C][mdns:177]: mDNS:
[19:40:32.898][C][mdns:177]: Hostname: airco
[19:40:32.917][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:32.955][D][fujitsu_general::airstage::h::Controller:096][UART_Event]: UART break!
[19:40:32.975][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:33.011][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:33.031][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:33.053][D][fujitsu_general::airstage::h::Controller:096][UART_Event]: UART break!
[19:40:33.072][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:33.092][D][fujitsu_general::airstage::h::Controller:096][UART_Event]: UART break!
[19:40:33.111][D][fujitsu_general::airstage::h::Controller:096][UART_Event]: UART break!
[19:40:33.131][D][fujitsu_general::airstage::h::Controller:096][UART_Event]: UART break!
[19:40:33.149][D][fujitsu_general::airstage::h::Controller:096][UART_Event]: UART break!
[19:40:33.202][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:33.239][D][fujitsu_general::airstage::h::Controller:096][UART_Event]: UART break!
[19:40:33.259][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:33.297][D][fujitsu_general::airstage::h::Controller:096][UART_Event]: UART break!
[19:40:33.380][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:33.400][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:33.433][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:33.453][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:33.507][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:33.527][D][fujitsu_general::airstage::h::Controller:096][UART_Event]: UART break!
[19:40:33.563][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:33.583][D][fujitsu_general::airstage::h::Controller:096][UART_Event]: UART break!
[19:40:33.704][D][fujitsu_general::airstage::h::Controller:096][UART_Event]: UART break!
[19:40:33.723][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:33.745][D][fujitsu_general::airstage::h::Controller:096][UART_Event]: UART break!
[19:40:33.763][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:33.783][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:33.802][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:33.906][D][fujitsu_general::airstage::h::Controller:096][UART_Event]: UART break!
[19:40:33.938][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:33.959][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:33.994][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:34.064][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:34.151][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:34.188][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:34.208][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:34.296][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:34.314][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:34.333][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:34.352][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:34.372][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:34.392][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:34.412][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:34.485][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:34.550][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:34.570][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:34.589][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:34.608][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:34.712][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:34.781][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:34.801][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:34.821][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:34.841][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:34.930][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:34.949][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:35.034][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:35.060][D][esphome::fujitsu_general_airstage_h_controller:102][UART_Event]: RX: 6D E3 E7 C3 CF FC 70 DC
[19:40:35.063][D][esphome::fujitsu_general_airstage_h_controller:102][UART_Event]: RX: 3F FF 37 C8 79 E7 5F F0
[19:40:35.067][D][esphome::fujitsu_general_airstage_h_controller:102][UART_Event]: RX: 9F 9F 0F 1F FF 83 E3 FB
[19:40:35.069][D][binary_sensor:041][UART_Event]: 'Standby Mode': New state is ON
[19:40:35.072][D][climate:427][UART_Event]: 'Airco' - Sending state:
[19:40:35.077][D][climate:430][UART_Event]: Mode: FAN_ONLY
[19:40:35.078][D][climate:435][UART_Event]: Fan Mode: QUIET
[19:40:35.081][D][climate:441][UART_Event]: Preset: ECO
[19:40:35.083][D][climate:447][UART_Event]: Swing Mode: OFF
[19:40:35.087][D][climate:457][UART_Event]: Target Temperature: 31.00°C
[19:40:35.090][D][esphome::fujitsu_general_airstage_h_controller:102][UART_Event]: RX: FF 3C FF FF FF FF 7F F3
[19:40:35.093][D][esphome::fujitsu_general_airstage_h_controller:102][UART_Event]: RX: 83 FF 07 87 FF C0 67 33
[19:40:35.112][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:35.205][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:35.224][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:35.243][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
Here’s my YAML config file:
esphome:
name: airco
friendly_name: Airco
esp32:
board: esp32-c3-devkitm-1
framework:
type: esp-idf
# Enable logging
logger:
level: DEBUG
# Enable Home Assistant API
api:
encryption:
key: "CpigjJvidYdb8GFdIuCAcgpajYFxdIrkfJG/Dd3Zlxo="
# Web server
web_server:
port: 80
ota:
- platform: esphome
password: "e2502c2f903070a953724635b8799c9c"
wifi:
ssid: !secret wifi_ssid
password: !secret wifi_password
on_connect:
then:
- switch.turn_on: wifi_led
on_disconnect:
then:
- switch.turn_off: wifi_led
# Enable fallback hotspot (captive portal) in case wifi connection fails
ap:
ssid: "Airco Fallback Hotspot"
password: "7SCwHEZb9Hrt"
captive_portal:
external_components:
- source: github://Omniflux/esphome-tzsp
- source: github://Omniflux/esphome-fujitsu-halcyon
sensor:
platform: uptime
name: "Uptime"
switch:
platform: gpio
pin: GPIO10
name: "Wifi_LED"
id: wifi_led
inverted: false
uart:
tx_pin: GPIO21
rx_pin: GPIO20
baud_rate: 500
parity: EVEN
rx_full_threshold: 120
climate:
platform: fujitsu-halcyon
name: None
controller_address: 1
I’ve also tried to disconnect the main controller and run the board as the master controller by setting the controller address to 0, but that didn’t work at all.
Does anyone have any idea why it is not working on my system?
Regards,
Arjan
In the log it have CRC error, so it wrong or the hardware itself
[19:40:35.090][D][esphome::fujitsu_general_airstage_h_controller:102][UART_Event]: RX: FF 3C FF FF FF FF 7F F3
[19:40:35.093][D][esphome::fujitsu_general_airstage_h_controller:102][UART_Event]: RX: 83 FF 07 87 FF C0 67 33
[19:40:35.112][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
[19:40:35.205][W][fujitsu_general::airstage::h::Controller:116][UART_Event]: UART parity error
Hey Team,
I’m having some issues and I’m hoping it just needs some amendments in the config files but has anyone has any luck with this panel? I’m using ESP32 chip which from what I can tell is working fine, but I still have a 12.1 error (Wired remote controller communication error)
Controller - AR-WDD1E (UTY-RVNYN)
Indoor Unit - ARTG36LHTA
Outdoor Unit - AOTG36LATL
