MITSUBISHI MSZ-HJxxxx are controllable via the CN105 connector

[Dr No]

Hi All,

MITSUBISHI MSZ-HJ xxxx air conditioners which are normally not controllable because not having a CN105 connector, are finally.

After analyzing the technical documentation the control card has a CN105 which is not mounted and on the other side 2 0603 resistors are not mounted either. So I bought connectors and now I control my MSZ HJ50VA without any problem thanks to a WEMOS mini D1 with the Swicago firmware.

The resistors; I started cautiously with 470ohms, it did not work I replaced them with 100ohms and now it works perfectly. these resistors are in series in the Rx and Tx connections, I am almost sure that if we put a piece of wire so 0ohms it will work just as well.

The connector is an angled version mounted flat on the IC it is a JST 2mm 5 pins reference S05B-PASK-2 Bought on Aliexpress:
https://fr.aliexpress.com/item/10050053 ... pt=glo2fra
it's not red but it still works

[HvdW]

That's a post I like.
Can you give some more explanation on how you have put it all together - Wemos pin layout, software, webpage where to find it all described - plus a working link to Ali's bazaar.
TIA Dr. No.

[Dr No]

Sorry for the link it's OK now

I'll be back probably tomorow for more explanations, It is time to eat now in France.

[Dr No]

I use a MQTT broker and domoticz. I add the Masurov plugin " Domoticz-MitsubishiHpMQTT-Plugin"

Here is the link :
https://github.com/Masurov/Domoticz-Mit ... QTT-Plugin
In the text of Masurov you'll find links to the arduino firmware of Swicago for ESP8266 and also the wiring of the JST female connector

I bought on Amazon some WEMOS D1 Mini of AZDelivery
https://www.amazon.fr/gp/product/B0754N ... UTF8&psc=1
Sorry for the French link but you'll can find an equivalent. The great advantage of this product you only need 4 wires and the JST connector. No need of 10K pull-ups and no need of regulator

WARNING : Take care of crossing Rx and Tx (Tx of connector to Rx of Wemos Mini D1 and Rx of connector to Tx of Wemos Mini D1)

That's all and it works perfectly since about 4 years

[solarboy]

I also use a Wemo D1 and MQTT to control my MSZ HR25 VFAC via the C105. Just a warning, be very careful of static on the Wemo and never connect to the USB port while it is plugged into the AC. I fried a 200€ PCB this way (laptop was charging so some earthing issue).

Otherwise it works very well.