Fujitsu AC Wifi controller.

This library reverse-engineers parts of the communication used by Fujitsu air conditioners, including those using the FGLair® mobile app.

FGLair is a registered trademark of Fujitsu General Limited. This project is not affiliated with or endorsed by Fujitsu. FGLair® app is not required when using this integration - everything runs local here.

Using this library you can control your Fujitsu AC through:

• 4 pin connector dedicated to UTY-TFSXW1:

  • Tested with:
  • ASYG09KMTB
  • ASYG09KMCC
  • ASYG12KGTB
  • ASYG09KGTB

• 4 pin connector dedicated to UTY-TFSXZ1:

  • ARXG18KLLAP
    • not fully tested yet, basic functions like mode change, temp sensors work.
    • pinout sequence is not confirmed yet, so check if it the same

• USB-type connector dedicated to UTY-TFSXF3:

  • Tested with:
  • ASTG18KMTC
  • ASTG09KMTC

If you want to support this project, you can buy ready-to-use dongle. Contact: benas.rag@gmail.com

Or you can build it yourself - you will find instructions below :)

This page is available at 192.168.1.1 when connected to the access point created by the dongle, when no config saved yet, or impossible to connect to WiFi

• DC/DC converter 12 -> 5 V (~2.65 € for bundle of 5pcs)
  Choose 5V version, also ensure you get right one. in case of bigger voltage, you will pass too high voltage to AC UART and risk to damage it
  (https://www.aliexpress.com/item/1005008257960729.html)

• ESP32 30 pin (~4.40 €)

• Connector (4P, 10cm/20cm) (~3.00 € for bundle of 5pcs, https://www.aliexpress.com/item/1005006294406922.html)

• Board (4x6, needs to be trimmed a little bit) (~2.00 € for bundle of 5pcs, https://www.aliexpress.com/item/1005007024264426.html)

• Logic level converter (~2.50 € for bundle of 5pcs, https://www.aliexpress.com/item/1005006968679749.html)

• Total parts cost for a dongle:

  • ~ 15.00 € (if you build one)
  • ~ 6.50 € each (if you build 5)

  You can also crimp your own plug (Connector PAP-04V-S, pins to crimp: SPHD-002T-P0.5) <- very time consuming if you do not have right tools for it.

!!! IMPORTANT !!!

Do not connect anything from air conditioner to external device, like your computer. If you touch AC GND with, lets say laptop GND, it will fry your laptop USB port and/or AC mainboard fuse. AC pins are not galvanically isolated and these voltages are not relative to earth GND.

 AC Socket       CN3903                 ESP32
1 (+12V) ------> V in+ ---> V out+ ---> 5V
2 (GND)  ------> V in- ---> V out- ---> GND
3 (DATA) -----------------------------> RX/16 (AC -> ESP)
4 (DATA) -----------------------------> TX/17 (AC <- ESP)

Pins from left to right 1 2 3 4

Circuit for JST type connector

Pinout for USB style socket:
Pin 1 - 12v
Pin 2 - AC_TX - 16 pin
Pin 3 - AC_RX - 17 pin
Pin 4 - GND

USB Pinout from top to bottom

1. Download Arduino IDE (I used 2.3)
2. File -> Preferences -> Additional boards manager URLs: http://arduino.esp8266.com/stable/package_esp8266com_index.json
3. Download required libraries:
   • this library - FujitsuAC (Benas09)
   • PubSubClient 2.8 (Nick O'Leary)
4. Open Arduino IDE -> File -> Examples -> FujitsuAC -> Controller
5. Select your ESP32 board:
   • Choose your board type Tools -> Board -> esp32 -> ESP32 Dev module
   • Choose your port Tools -> Port -> /dev/ttyUSB0 (or similar)
   • Sketch -> Upload using programmer (when uploading from MAC, you have to set upload speed to lowest - 460800, otherwise you will get an error while uploading)

Additional button can be used for credentials reset functionality - uncomment RESET_BUTTON and set to corresponding pin. When you press this button (pull corresponding pin to GND) - controller deletes given credentials, reboots and goes to point

1. When controller boots up, it will create access point Fujitsu-uniqueId
2. Connect to this access point with your computer/mobile phone
3. Go to 192.168.1.1
4. Fill in WiFi, MQTT credentials, name your device and click Submit. (Device password will be required for OTA updates)
5. Dongle will reboot and connect to your wifi network.
6. If everything is ok, new AC device should appear in HomeAssistant MQTT integration

1. Open Arduino IDE
2. File -> Examples -> FujitsuAC -> Controller
3. Select your ESP32 board:
   • Choose your board type Tools -> Board -> esp32 -> ESP32 Dev module
   • Choose your port Tools -> Port -> Network ports -> "YourDongleName at your-dongle-ip" (disappears time by time, so wait or reload Arduino IDE to apear again)
   • Sketch -> Upload

Since 1.1.6 one-click network update is available. The dongle checks for new version every 24 hours (and immediately after reboot). To update, just click "update firmware" button in HA and wait.

Chip list for prebuilt firmwares:

• ESP32
• ESP32-S3
• others will ignore update request