Oh yeah that could be a great start, mqtt could be fine for my needs, looking forward to see how you got it to work!
and Happy New Year to you too! 
It is now on github:
I just quickly moved it there, without useful docs or anything, sorry for the mess.
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great i gonna have a look asap, thanks a lot!
hi, I’m following your project, I’m not an expert, I wanted to ask you if you could describe the connections between the d1 mini and the max 485, and if it is necessary to install the 120 hom resistor between the terminals of the max 485. if I can get it to work I will try to integrate it with Home Assistant. Anyway thanks for what you do and sorry my translator language.
You PROBABLY do not need the resistor for these transmission speeds IF the line is not long and it is a low noise environment. But it definitely won’t hurt. PM me your email address for details.
Thanks for getting back to me so quickly
Thanks …
hi Chris H I have some problems connecting the max 485 to the D1 mini
are pin DE and pin RE of max 485 connected together on pinD0 of D1mini?
pin D1 and pinR0 of max 485 on which pins are connected on D1 mini?
I have the following connections:
DI → D1
DE → D2
RE → D3
RO → D4
ok and the 5volts and the ground can I take them directly on the fan coil board?
i saw that there is a free vcc5 and GRD connector.
Thanks…
Not sure about that.
I have a USB power supply in there.
Any success?
I am new in this forum but looking for the documentation of the rtu registers.
Could you share the document you used?
Servus Peter,
Maybe this helps: olimpia_splendid_bi2_modbus_controller/registers.txt at testing/mqtt-fixes · dumpfheimer/olimpia_splendid_bi2_modbus_controller · GitHub
If you want the “full” documentation pm me your email. It contains a bit more technical information but less registers.
Hi guys, please could you clarify pinout of display ? I already have PLC (Loxone with Modbus RTU extension) and I am planning to connect it directly and control with Loxone Home. Everything is clear to me, except where to put RS485+ , RS485- and GROUND (on display ? ) Which connector ? Do you guys have some photo please ?
Thanks a lot
Hey! Sorry, I missed your message. What do you mean with “display”?
Really happy having found this post. We are just replacing gas heating by heat pump, and we were proposed/asked to replace some radiators by fan coil units. Proposed were zealux that have Wifi and Tuya app, but heating shall work w/o cloud, and no idea about ability to repair or product support over years, or alternatively Olimpia Splendid with the more base modbus. It’s really hard to find such fan coil units that can be integrated in existing smart home system. So, again, curious to see your efforts.
I have worked with raspi and io.broker and home assistant. Currently, I control all heatings by smart home setup (indirectly via Lupusec alarm system). I can control, and monitor. Looking for similar for future heating solution.
What is possible with your implementation? Control, sure… Also read out of current state/values? Did you manage to have touch control and modbus remote control at the same time? It should be somehow possible as vendor says in product information this works with their SiOS control?.. while the translation is hard to understand in that case.
Did I get it right the hardware setup is a Arduino with USB power connected to 230V, and Arduino with WiFi implements the HTTP server that get’s commands via WiFi.
Is all that you did and documented in the github? I am happy about all possible information for the decision about our future fan coil unit supplier. Once units are here I may then start learning Arduino.
I just saw this post passing by, and i remember some people where working in a heatpump in a thread from me…
Maybe there is some useful info there?
(I myself use Olimpia Splendid AC’s)
Hello @dumpfheimer,
could I also get the “full” documentation. I would be please if you could comment on my post from Jan 3.
Hi! Sorry for the late reply.
Yes, it is possible to read the valve states. There are 2 valves and a water temerature sensor that can be read. Additionally there are a few settings that can be set, but you would need to set registers over HTTP requests, not too complicated but not user friendly either.
I myself have been using the controllers for 3 fan coils and a in-wall device from Viessmann (which buy them from Olimpia Splendid) and I am quite pleased.
Just like yourself I do not like the idea of having stuff in the cloud and furthermore I distrust vendor updates. Don’t see any issues with updates over Modbus =)
While I am glad to help you with any issues you encounter: As you have noticed I frequently miss messages, because I postpone them and forget about them.
What I am trying to say is: If you like tinkering and have some technical knowledge and are willing to put some effort into it, I think my solution just might be for you. If you want reliable support and want to be able to “blame” someone if something does not work you may want to stick with an actual product.
You get the gist.
Just to point out another reason why I went through the trouble:
We have a heat pump for only our house. Which means it tends to have too much power over all. So the heat pump would constantly run for only 3-5 minutes and turn off again. Which causes a lot of strain and wear. And, just because a fan coil is on does not mean it is “consuming” water. When you are in control of the fan coil you can force fan coils to start consuming water to synchronize them and extend the duration of the heat pump, reducing wear and improving efficiency.
The Olimpia Splendid devices are not perfect. I have my issues with them. But all in all I am happy with it.
So, back to your questions:
TL;DR
- The integration can: control the device (set setpoint, change mode, change speed, change oscillation) and can read valve states and water temperature.
- Touch control does NOT work when Modbus is enabled. Also, the IR remote does NOT work. I was thinking about adding IR support but tbh it turned out I don’t need it. I do not know about SiOS. They might mean controlling the fan coil over a sencond device in the same room, tough.
- The setup is best powered by a 5V rail from the fan coils controller board. This is important to prevent issues with non-common ground.
- Everything from the controller is on GitHub (except the PDF from Olimpia Splendid, I was not sure if I am allowed to publically share that). The way I control the controllers, however, is not. I have a very custom heating controller which would not be a lot of use to anyone else.
- PM me your email address and I can send you the documentation I got from OS.
did you integrate it into home assistant? I’m curious on how to do it