Hi. My ventilation box is G90-300 and it is equipped wirh RS485 instead of RS232. Can anyone confirm the protocol is the same?
Based on the available documentation the protocol should be the same
Protokollbeschreibung_ComfoAir.pdf
Hmmm, build an RS485 to TTL converter based on ADM485 and NE555 (for auto TX/RX switching). Flashed https://github.com/wichers/esphome-comfoair and it is sending requests but seems not getting answers. Can anybody please post some valid answers for the esphome-comfoair requests, so i could at least test if my hardware is working? The log is showing only:
[11:40:43][D][comfoair:577]: getting valve status
[11:40:44][D][comfoair:617]: getting ventilation level
[11:40:45][D][comfoair:622]: getting temperatures
[11:40:45][D][comfoair:584]: getting error status
[11:40:46][D][comfoair:594]: getting bypass control
[11:40:46][D][comfoair:569]: getting fan status
[11:40:47][D][comfoair:577]: getting valve status
Update, tried my self build adapter wirh USB/RS485 interface, it works fine. Tried to inject some answers via Realterm, esp gives checksum error in log, so it is getting data. Tried to connect to the ventilation box with usb to rs485 adapter and StockAir mainanence 2.53, it does not work 
I remember i tried to connect with this software few years ago, i had this software on my old laptop. In my head i remember a sucessfull connect, but can not reproduce it and i dont see any logs. Maybe i remember wrong. Any ideas how to connect with this RS485 box?
Do you disconnect the standard control panel? Only one rs device can be connected at a time (at least in case of RS232 port)
I have RS485. I have no other control panel, only the display build in in the unit. Should this be disconnected?
So. There is progress, even when small.
My ventilation is G90-300, it seems to use the same protocol as CA-500 with RS485. Not sure if itās an older version or other difference, but it
Protocoll information I found here
https://matsab.de/de/heimautomatisierung/comfoair
Is anyone willing to help me and modify the confoair for esphome from here https://github.com/wichers/esphome-comfoair to work with this RS485 protocol?
My programming skills are not high, but i hope i can do some % of the workā¦
My communication try:
SEND
07 F0 00 85 00 32 07 0F
GOT
07 F3
07 F0 00 84 0A 00 12 00 30 4E 31 86 BE 01 00 41 07 0F
07 F0 00 84 0A 00 12 00 30 4E 31 86 BE 01 00 41 07 0F
07 F0 00 84 0A 00 12 00 30 4E 31 86 BE 01 00 41 07 0F
07 F0 00 84 0A 00 12 00 30 4E 31 86 BE 01 00 41 07 0F
07 F0 00 84 0A 00 12 00 30 4E 31 86 BE 01 00 41 07 0F
Hi. Iām very interested to use your ComfoAir integration, but not sure how to install it. Iām running home assistant on a Raspberry Pi4 with itās home assistant OS. Sudo doesnāt work on that. Can you give me some hints on how to get started?
Iāve never used HA OS but from what I know you canāt get full access to os command line without major tinkering. In such case you need a device (e.g. another RPi or an ESPhome compatible module e.g. NodeMCU). For a linux install (e.g. another RPi) you can find pretty complete and detailed guide here:Zehnder ComfoAir CA350 integration via serial connection (RS232) and MQTT
and for ESPHome installation check out the github of that project https://github.com/wichers/esphome-comfoair
Depending on which option you choose either come back to me and other contributors on the āshare your projectā topic (first link) or get in touch with the author of ESPHome port (second link).
Hello,
As explained by @adorobis, you can follow the guide, it will works without sudo (on the HA side I mean, Iām using sudo on the RPI connected to the MVHR). Iām also using HA OS.
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Thanks. Now I realize that I have to run your pyton code on another device. I wrongly assumed that it could run on HA OS directlyā¦
I will give it a try, but first need to modify the code to work with the different command set of my old WHR950 that uses RS485. But thanks to the links of ākunaā a few forum posts up I think I can manage. When I get it to work I will report back.
Hi All. I managed to get the script modified to support my WHR950 based on the RS485 communication protocol in kunaās post:
https://matsab.de/de/heimautomatisierung/comfoair
What is working:
- Reading temperatures (only 3 sensors are supported, supply temperature to the house is not measured)
- Fan % and RPM
Not yet working:
- Reading comfort temperature
- Controlling fan level (not sure why)
- Some status stuff I still need to figure out
Are you willing to add support for my unit to the āofficialā code? I can send my modified version.
Which solution have you implemented? ESP based or the python script and connection to a computer? The best would be to file a feature request on the respective git repository.
Feature request submitted. I modified your python script running on a computer (my NAS in this case). Will probably continue to tweak it over the coming time period to try and get some of the missing features workingā¦
This was pretty awesome, thanks @wichers !
I found a slick board with esp8266 and rs232 level translation. Too bad it doesnāt take 12v, but thatās minor.
https://www.amazon.com/gp/product/B08GY2GTW5
I havenāt decided if Iāll use the relay to switch the TX line between esp and the existing control or just use a switch for it.
Iām thinking about designing a simple board that could be connected between the ComfoAir and the CC-EASE.
It would be a some effort to write a firmware that supports both connections (HA and the original) but it is possible 
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Keeping fingers crossed; I have actually replaced my CC controller with a HA wall mounted tablet so giving much more options than just CC. And benefited from the cabling that was already there (supplying power from ComfoAir )
You can also use simple NodeMCU - it has the RS232 built in as well and there are nice 12v power supply boards as well (example here: https://allegro.pl/oferta/modul-plytki-testowej-bazowej-nodemcu-v3-arduino-9565039929)
Hi, Iām behind the first link you mentioned at the head of your post,
Regarding the access to the ventilation unit contemporaneously by multiple controllers (such as the ESP, Homeassistant, FHEM, Jeedom, opens) AND the comfosense, it is possible if a piece of software manages the various requests from the controllers (the RS232 access being single controller based). On the github project, thereās a server (VMCserver) that does that. This enables the unit to be controlled by the comfosense, web pages and FHEM.
Basically the server provides IP connections to the clients and connects to the serial port of the ventilation unit.
Thus each client needs to connect to the server via TCP/IP, this is easily done through socat or ser2net processes that interfaces a serial port to a network connection. The client (say HASSIO) connects the to serial side and is thereby connected to the ventilation unit via the server that handles the requests of the client and sends back the replies from the unit.
The most interesting part would be to have an integration to the Home Assistant e.g. via MQTT. Have you considered this?