Hello there,
Please did anyone had a chance to integrate Nea Smart system from Rehau? The heating system control system.
Thank you very much
Martin
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I’m Also interested in this integration…
The producer’s app is prehistoric 
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Hello,
if you’re interested I can program such integration.
I have some doubts, thou, because cloud integration is VERY bad for your home security, and I personally suggest you TOTALLY disable cloud connection to the REHAU servers.
I will not disclose the reasons behind that, but I personally did disable it and I am planning on using NEA SMART with local connections only.
This would be easy to integrate with HA and much more secure, but not very easy to setup, since local integration must be done via WIFI.
What would you like from such integration?
I am also interested in integrating Rehau Nea Smart to Home Assistant. If I am right there is a possibility to connect to the Rehau Nea system by Modbus protocol. Are you familiar about that?
+1 interested in this as well.
I would love to have a connecting to my 3 rehau “bars”… to see current and change target temperature as a first step.
Next might be changing auto/away/holiday/etc status.
Hi! I’m also interested to integrate my rehau nea smart.
I’ve 9 thermostats and i would lire to control by home assistant. Someone has anyone managed to integrate it?
Thanks
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+1 for integration
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Hi! I’m also interested to integrate my Rehau system.
I’m running Nea Smart 2.0.
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Hello again,
i’ve done some integration tests and it can be done.
Before I go on and maybe make a public integration I would like to understand if you would accept the integration to work only when rehau is set to ACCESS POINT mode.
This would make the REHAU app (on your phone) not working.
If you have the sensors in your rooms they will keep working as usual.
Also you will have to connect the computer running Home Assistant to the REHAU WIFI together with your usual connection. This is not very easy or convenient.
Otherwise, the integration can be sone with REHAU working as usual, but in this case I must alert you that I discovered a serious bug in REHAU systems that makes your HOME data public.
I already disclosed the bug to rehau but they seem to not care at all.
I personally disconnected REHAU from the internet as I don’t want my data (address, geo location, presence…) to be publicly available!
Let me know!
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Let everyone know where I am! 
I don’t care at all: just want to control my heating system without that shitty app 
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I don’t think you get it … but ok for me…
I also would appreciate for this integration. I’ll have this system in my new home.
Later on, I can also help with development.
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Hello,
I also have a Nea Smart 2.0 system with 6 thermostats. As an alternative to direct integration with Home Assistant, with an ESP32 and a TTL to RS485 converter, I made a ModbusRTU server that I can then read via ModbusTCP (you can use MQTT too) for example from NodeRed and from there do what you want. With this I can read the system parameters (and in principle also modify them).
The system still needs to be improved (I am not a professional electronic or programmer). If anyone is interested in lending a hand, they are welcome.
Hi @pistunut I am really interested in doing something to help you in this project. Let me know how you should go on, in order to evaluate what I can do.
I am old sw programmer, but now my job is different. However I like to play with HA e I am still able to learn new program language.
Ciao
Hi @vcalzolari64,
At the moment, the project is working. I changed the way that it works. Now, the ESP32 makes a ModbusRTU server that recives data from Rehau system. Then, data is send to my system via MQTT to Node-RED where I store data to InfluxDB and create sensors directly to HA.
I discarded the Modbus TCP option because (although it worked for me) what it did was duplicate the registers within the ESP32 and it had more stability problems than with MQTT.
Adeu!
Hi @pistunut,
Thank you for answering me. Your project looks great and I would like to ask you some questions:
- Is The ModbusRTU server connected to the Sysbus port of the nea smart base station? If so, what the communication configuration to use? I am referring to baud rate, stop bits, and so on.
- Where I can find documentation about that connection?
- Could you share the registers table to read/write the nea smart registers?.
I would thank you in advance for your answer
Ciao
Hi @vcalzolari64 ,
Glad to be able to share the project and look if it can be improved.
About your questions:
- Yes, the RTU server is connected to the Rehau base SYSBUS. The configuration parameters are:
- Slave address: 240 or 241 (I use 240).
- Baudrate: 38400
- Parity: none
- Bit order: MSB
- First address: 0
- I used an XY-017 UART to RS485 and connected A+ to 1 of the SYSBUS, B- to 2 of the SYSBUS and the groud to GND of the SYSBUS.
-
Information can be found in the Rehau KNX Gateway documentation (here). I had no knowledge of KNX but on the Rehau web site there is a prepared KNX project and I analyzed it with the free version of the KNX software. There I could see all the control points they prepare.
-
In the same document, there is the table of registers as well as their interpretation. As an example:
- address 1 is the global operation mode
- address 2 is the global operation status
- …
- address 100 is the local operation status of one of the thermostats
- address 101 is the setpoint of one of the thermostats
- address 102 is the current temperature of one of the thermostats
- address 110 is the humidity of one of the thermostats
- …
I have all this in the sketch for the ESP32, if you want I could also share it so you don’t have to start from scratch. What I don’t know how to share it…
Adeu!
Hi @pistunut ,
Thank you very much for your answer.
You can try to send information about ESP32 to my direct email address [email protected].
I am excited to see it and start to integrating Nea Smart system to my HA.
Ciao
Vittorio
Hi @postunut @vcalzolari64 ,
I’d like to integrate a Rehau Nea Smart in Node-Red too. I’m interested in both modbus RTU and TCP ways, can you share something?
Thank you and great work!
Hi @franzer73,
@postunut has already integrated nea smart to HA by means Arduino project, Modbus RTU, MQTT and NodeRed. He shared with the sketch documentation where I understood hoe to map the Modbus registers to read the Nea Smart information.
Currently I am trying to use a Modebus TCP converter (USR-W610) to connect to Nea Smart station and to send the data over TCP so I can read it with Home Assistant using the ModBus integration.
I am working on this project since couple of days therefore I don’t finish yet.
Once it finished I will share all project documentation with whom is interested in.
Regarding the documentation I can share the documentation about the Gateway Nea Smart 2.0 where you can find the information about the registers mapping.
[https://www.rehau.com/downloads/813496/nea-smart-2-0-knx-gateway.pdf] (https://www.rehau.com/downloads/813496/nea-smart-2-0-knx-gateway.pdf)
Regarding the documentation project of @pistunut, I think he will be glad to share with you.
Ciao