FujitsuAC Integration

plains203 · September 10, 2025, 10:02am

Yeah, good idea, I’ll confirm that tomorrow.

zodyking · September 10, 2025, 10:59pm

no i wish, its innovair

plains203 · September 11, 2025, 6:53am

The USB connector pinout on the Airconditioner head unit & the wire colour for a USB lead is as follows.

Pin 1 - 12v - Red Wire
Pin 2 - RX - White Wire
Pin 3 - TX - Green Wire
Pin 4 - GND - Black Wire

This means you need to connect Pin 2 to your TX pin on your microcontroller & Pin 3 to your RX pin on your microcontroller.

kiwizznz · September 13, 2025, 1:40am

No luck - got it all connected but doesn’t appear to be able to get any information from the AC unit ( ASTG09KMTC ). Got this from the MQTT verbose stuff:

fujitsu/80f3daba1bc4/set/restart restart
fujitsu/80f3daba1bc4/status offline
fujitsu/80f3daba1bc4/status online
fujitsu/80f3daba1bc4/debug/info MQTT Connected
fujitsu/80f3daba1bc4/debug/info Base entities registered
fujitsu/80f3daba1bc4/debug/info Switch 'power' registered
fujitsu/80f3daba1bc4/debug/info Switch 'vertical_airflow' registered
fujitsu/80f3daba1bc4/debug/info Switch 'vertical_swing' registered
fujitsu/80f3daba1bc4/debug/info Switch 'powerful' registered
fujitsu/80f3daba1bc4/debug/info Switch 'economy_mode' registered
fujitsu/80f3daba1bc4/debug/info Switch 'energy_saving_fan' registered
fujitsu/80f3daba1bc4/debug/info Switch 'outdoor_unit_low_noise' registered
fujitsu/80f3daba1bc4/debug/info Switch 'minimum_heat' registered
fujitsu/80f3daba1bc4/state/address_0001 0000
fujitsu/80f3daba1bc4/state/address_0101 0000
fujitsu/80f3daba1bc4/state/address_0110 0000
fujitsu/80f3daba1bc4/state/address_0111 0000
fujitsu/80f3daba1bc4/state/address_0112 0000
fujitsu/80f3daba1bc4/state/address_0113 0000
fujitsu/80f3daba1bc4/state/address_0114 0000
fujitsu/80f3daba1bc4/state/address_0115 0000
fujitsu/80f3daba1bc4/state/address_0117 0000
fujitsu/80f3daba1bc4/state/address_011A 0000
fujitsu/80f3daba1bc4/state/address_011D 0000
fujitsu/80f3daba1bc4/state/address_0120 0000
fujitsu/80f3daba1bc4/state/address_0130 0000
fujitsu/80f3daba1bc4/state/address_0131 0000
fujitsu/80f3daba1bc4/state/address_0142 0000
fujitsu/80f3daba1bc4/state/address_0143 0000
fujitsu/80f3daba1bc4/state/address_0150 0000
fujitsu/80f3daba1bc4/state/address_0151 0000
fujitsu/80f3daba1bc4/state/address_0152 0000
fujitsu/80f3daba1bc4/state/address_0153 0000
fujitsu/80f3daba1bc4/state/address_0154 0000
fujitsu/80f3daba1bc4/state/address_0155 0000
fujitsu/80f3daba1bc4/state/address_0156 0000
fujitsu/80f3daba1bc4/state/address_0170 0000
fujitsu/80f3daba1bc4/state/address_0171 0000
fujitsu/80f3daba1bc4/state/address_0193 0000
fujitsu/80f3daba1bc4/state/power off
fujitsu/80f3daba1bc4/state/mode auto
fujitsu/80f3daba1bc4/state/temp 0.0
fujitsu/80f3daba1bc4/state/fan auto
fujitsu/80f3daba1bc4/state/address_1010 0000
fujitsu/80f3daba1bc4/state/vertical_swing off
fujitsu/80f3daba1bc4/state/address_1022 0000
fujitsu/80f3daba1bc4/state/horizontal_swing off
fujitsu/80f3daba1bc4/state/address_1031 0000
fujitsu/80f3daba1bc4/state/address_1034 0000
fujitsu/80f3daba1bc4/state/vertical_airflow unknown
fujitsu/80f3daba1bc4/state/horizontal_airflow unknown
fujitsu/80f3daba1bc4/state/economy_mode off
fujitsu/80f3daba1bc4/state/minimum_heat off
fujitsu/80f3daba1bc4/state/human_sensor off
fujitsu/80f3daba1bc4/state/address_1103 0000
fujitsu/80f3daba1bc4/state/address_1104 0000
fujitsu/80f3daba1bc4/state/address_1105 0000
fujitsu/80f3daba1bc4/state/address_1106 0000
fujitsu/80f3daba1bc4/state/address_1107 0000
fujitsu/80f3daba1bc4/state/energy_saving_fan off
fujitsu/80f3daba1bc4/state/address_1109 0000
fujitsu/80f3daba1bc4/state/powerful off
fujitsu/80f3daba1bc4/state/outdoor_unit_low_noise off
fujitsu/80f3daba1bc4/state/address_1141 0000
fujitsu/80f3daba1bc4/state/address_1144 0000
fujitsu/80f3daba1bc4/state/address_1200 0000
fujitsu/80f3daba1bc4/state/address_1201 0000
fujitsu/80f3daba1bc4/state/address_1202 0000
fujitsu/80f3daba1bc4/state/address_1203 0000
fujitsu/80f3daba1bc4/state/address_1204 0000
fujitsu/80f3daba1bc4/state/address_1400 0000
fujitsu/80f3daba1bc4/state/address_1401 0000
fujitsu/80f3daba1bc4/state/address_1402 0000
fujitsu/80f3daba1bc4/state/address_1403 0000
fujitsu/80f3daba1bc4/state/address_1404 0000
fujitsu/80f3daba1bc4/state/address_1405 0000
fujitsu/80f3daba1bc4/state/address_1406 0000
fujitsu/80f3daba1bc4/state/address_140E 0000
fujitsu/80f3daba1bc4/state/address_2000 0000
fujitsu/80f3daba1bc4/state/address_2020 0000
fujitsu/80f3daba1bc4/state/address_2021 0000
fujitsu/80f3daba1bc4/state/address_F001 0000
fujitsu/80f3daba1bc4/debug/send 00 00 00 00 04 00 00 00 00 FF FB
fujitsu/80f3daba1bc4/debug/send 00 00 00 00 04 00 00 00 00 FF FB
fujitsu/80f3daba1bc4/debug/send 00 00 00 00 04 00 00 00 00 FF FB
fujitsu/80f3daba1bc4/debug/send 00 00 00 00 04 00 00 00 00 FF FB
fujitsu/80f3daba1bc4/debug/send 00 00 00 00 04 00 00 00 00 FF FB
fujitsu/80f3daba1bc4/debug/send 00 00 00 00 04 00 00 00 00 FF FB
fujitsu/80f3daba1bc4/debug/send 00 00 00 00 04 00 00 00 00 FF FB
fujitsu/80f3daba1bc4/debug/send 00 00 00 00 04 00 00 00 00 FF FB
fujitsu/80f3daba1bc4/debug/send 00 00 00 00 04 00 00 00 00 FF FB
fujitsu/80f3daba1bc4/debug/send 00 00 00 00 04 00 00 00 00 FF FB
fujitsu/80f3daba1bc4/debug/send 00 00 00 00 04 00 00 00 00 FF FB
fujitsu/80f3daba1bc4/debug/send 00 00 00 00 04 00 00 00 00 FF FB
fujitsu/80f3daba1bc4/debug/send 00 00 00 00 04 00 00 00 00 FF FB
fujitsu/80f3daba1bc4/debug/send 00 00 00 00 04 00 00 00 00 FF FB
fujitsu/80f3daba1bc4/debug/send 00 00 00 00 04 00 00 00 00 FF FB
fujitsu/80f3daba1bc4/debug/send 00 00 00 00 04 00 00 00 00 FF FB
fujitsu/80f3daba1bc4/debug/send 00 00 00 00 04 00 00 00 00 FF FB
fujitsu/80f3daba1bc4/debug/send 00 00 00 00 04 00 00 00 00 FF FB
fujitsu/80f3daba1bc4/debug/send 00 00 00 00 04 00 00 00 00 FF FB
fujitsu/80f3daba1bc4/debug/send 00 00 00 00 04 00 00 00 00 FF FB
fujitsu/80f3daba1bc4/debug/send 00 00 00 00 04 00 00 00 00 FF FB
fujitsu/80f3daba1bc4/debug/send 00 00 00 00 04 00 00 00 00 FF FB
fujitsu/80f3daba1bc4/debug/send 00 00 00 00 04 00 00 00 00 FF FB
fujitsu/80f3daba1bc4/debug/send 00 00 00 00 04 00 00 00 00 FF FB
fujitsu/80f3daba1bc4/debug/send 00 00 00 00 04 00 00 00 00 FF FB
fujitsu/80f3daba1bc4/debug/send 00 00 00 00 04 00 00 00 00 FF FB
fujitsu/80f3daba1bc4/debug/send 00 00 00 00 04 00 00 00 00 FF FB
^C

I have USB white connected to D16, and green to D17:

And the Arduino bit:

#define RXD2 16
#define TXD2 17

Photo for anyone curious:

Tried swapping the TX and RX but didn’t seem to make any difference. What can I try next? I’m not using a logic level shifter at the moment.

Cheers!

Benas · September 13, 2025, 5:19am

Hi.
Did unit started to flash its LEDs to show communication error? If no, it does not see signal. It happened with one of my 4 units (ASYG12KGTB). Logic level converter fixed that.

I used this:
https://www.aliexpress.com/item/1005006968679749.html?spm=a2g0o.order_list.order_list_main.35.71a01802aRlDFY

Connection circuit for logic converter:

ESP 3.3V pin → LV
ESP GND → LV GND
ESP 17 → LV4
ESP 16 → LV3

HV → ESP VIN (5V)
HV GND (did not used, it is shorted with LV GND anyway)
HV4 → AC DATA PIN 4 (data from ESP)
HV3 → AC DATA PIN 3 (data to ESP)

Adjust these pins by your connector type

@plains203 unit similar to yours, worked with SoftwareSerial controller code without logic converter. With hardware uart it is not seeing signal as well (we are going to try with logic level converter).

Mine one unit did not work nor with SoftwareSerial nor with hardware uart until I used logic lev converter.

Other 3 my units works well without it.

kiwizznz · September 14, 2025, 2:50am

Thanks @Benas . Ordered the logic level converter and will give it a go when it arrives. Appreciate you sharing the wiring details too!

Drafted this:

I wonder if it would be simple to order something like this premade from one of those circuit builder sites like pcbway.

Benas · September 14, 2025, 6:51am

My units have different socket, but based by @plains203 given pinout, I think you swapped TX and RX.

I checked jlcpcb couple weeks ago, and learnt that they dont have such premade modules like DC/DC converter or logic converter and its is needed to design erverything by self

Nekmo · September 16, 2025, 7:06pm

Bought. If you tell me what to do, I can reverse engineer it.

Benas · September 17, 2025, 5:33am

Hello.

Confirm that this is also 12V (possible there is a label on the dongle).
Check if VCC and GND are the same like in @kiwizznz schematic (I don’t know from which side pins are counted, so do not mix them )
Upload Sniffer example from library. There are 2 “virtual” uarts, 16 and 17 pins are used for receiving data, 25 and 26 pins are not used.
Make some extension cable from AC to OEM dongle.
Build Sniffer hardware:

ESP32
Logic level converter
Tap extension data lines to logic level converter corresponding HV side inputs
Connect ESP GND with extension cable GND

Power ESP from powerbank (do not power it from external source, like wall power adapter or computer, when connecting to AC)
Make sure you get wifi and mqqt connection, listen “fujitsu/sniffer/#”, you will get “fujitsu/sniffer/debug” → “Connected”
When ESP is running and OEM dongle wired to Sniffer, plug extension cable to AC
You will get all data packets to MQTT fujitsu/sniffer/rx, fujitsu/sniffer/tx topics
Collect them at least 30 seconds after you start receiving them.
Then you can control your AC with OEM fujitsu app and you will also get commands in MQTT

Also, before connecting everything to AC unit (when connecting to AC - only powerbank, no wires to wall power adapters or laptop), you can power your dongle from 12V power adapter to check if Sniffer is correctly receiving data packets from the dongle (you will get some packets in one of virtual uarts.

Ask if something is not clear

Nekmo · September 18, 2025, 8:42pm

I don’t have a Logic level converter, I will buy one, thanks!

kiwizznz · September 21, 2025, 5:24am

Did some janky wiring/soldering but got the logic level converter hooked up and it now appears to be working! Nice.

kiwizznz · September 21, 2025, 5:25am

I’ve been wondering if we could have someone on fiverr design a proper circuit (with some safeguards etc) and then we could just have someone like pcbway make the units.

Benas · September 21, 2025, 6:04am

I am trying to make it on easy eda, but it is first time I am using such software, so it can take a while

Benas · September 23, 2025, 10:06am

Can you confirm pinout? (Its oem controller view)

From top:
12V
AC_RX (esp tx pin 17)
AC_TX (esp rx pin 16)
GND

Or flip and counting from top:
GND
AC_TX (esp rx pin 16)
AC_RX (esp tx pin 17)
12V

kiwizznz · September 23, 2025, 10:45am

Hey that looks fancy. Hard to tell as I’m using this: USB2.0 to Dupont female 1P line 4 holes Dupont female head to Dupont 2.0 to wire USB2.0 conversion line - AliExpress 44

Black/Red are sorted. I think I’ve got white (TX from the AC) and green (RX for AC). Not sure on the ‘order’ though. I can see if I can work them out with a multimeter if that helps?

kiwizznz · September 23, 2025, 10:55am

So from the top when its (my cable thing) plugged in to the AC unit (like the 'connector side in your image but rotated 180/flipped):

PIN1 - RED - 12v
PIN2 - WHITE - TX
PIN3 - GREEN - RX
PIN4 - BLACK - GND

Benas · September 23, 2025, 11:01am

Ok, I will use @Alejandro12120 image, to be more clear:

PIN1 - RED - 12v (top)
PIN2 - WHITE - TX
PIN3 - GREEN - RX
PIN4 - BLACK - GND (bottom)

Yes?

kiwizznz · September 23, 2025, 11:05am

I can’t quite make out the orientation in that photo on the AC side. ‘top’ here I’ve marked pink:

The AC side is pretty hard to photograph:

Benas · September 23, 2025, 11:06am

Thank you

Benas · September 23, 2025, 4:10pm

Almost done. Needs some more tweaks and hope that it will work

Will PCB 56x34 mm fit easily or not?

Edit: shrinked to 52x30, so it will fit