Nefit / Buderus data/control via Arduino / ESP8266 to Domoticz (directly without OpenTherm module or Easy)

[peternl]

I have read this method for capturing data from a Nefit boiler locally with much interest.
My setup is ass follows:
- Nefit Ecomline HRC (with is reporting via the iRT protocol).
- Nefit Easy Connect adapter
- Nefit Easy thermostat.
I suppose that the Nefit Easy Connect Adapter is translating the iRT protocoll in the EMS protocol. Is that true??
And, when this is true, is it then possible to make a parallel connection: two lines going to the thermostat and two lines (parallel) to the interface board??

[bbqkees]

The adapter translates between iRT and EMS. But I don't think you can't get a lot of info from the boiler via EMS.
You likely won't get the default broadcast messages as on the EMS bus. And for the Easy nothing is properly reverse engineered yet.

[peternl]

Thanks for the info.
It's always more complicated than one thinks at first instance!

[friedl100]

Hallo Kees,

i own a Buderus GB212 with no RC35, RC20 or something else. The boiler is only controlled by an external 0-10V signal.
The output on Arduino Mega Serial Monitor of EMSBusSimpleRegisterReadRequest and EMSBusDumpToSerial works fine, but with EMSBusReceiveExample i get no values. Only when I turn off and on the boiler, I get once the right values! Do you have any idea what is going wrong?

Thanks Friedl

[bbqkees]

Perhaps your boiler only sends a message 0x18 at startup.
So you need to request this message yourself. The EMSBusReceiveExample does not request it, it just listens in so you never get any updates.
Or can you see message 0x18 with the serial dump sketch?

[friedl100]

Yes, the message 0x18 is displayed in the Serial Monitor with the serial dump sketch:

----------------snip------------------

EMS bus dump started.
Received datagram.
-----Datagram----- BYTES=17
HEX: 0x8 0x0 0x18 0x1B 0x0 0x0 0x0 0x0 0x0 0xF 0x7B 0x24 0x0 0x0 0x40 0x0 0x0
-----End of Datagram-----
Received datagram.
-----Datagram----- BYTES=17
HEX: 0x8 0x0 0x18 0x1B 0x0 0x0 0x0 0x0 0x0 0x10 0x25 0x24 0x0 0x0 0x6B 0x0 0x0
-----End of Datagram-----
Received datagram.
-----Datagram----- BYTES=8
HEX: 0x12 0x8 0x1A 0x0 0x24 0x35 0x0 0x0
-----End of Datagram-----
Received datagram.
-----Datagram----- BYTES=17
HEX: 0x8 0x0 0x18 0x1B 0x0 0x0 0x0 0x0 0x0 0x10 0xCF 0x24 0x0 0x0 0x74 0x0 0x0
-----End of Datagram-----
Received datagram.
-----Datagram----- BYTES=17
HEX: 0x8 0x0 0x18 0x1B 0x0 0x0 0x0 0x0 0x0 0x11 0x79 0x24 0x0 0x0 0xA9 0x0 0x0
-----End of Datagram-----
Received datagram.
-----Datagram----- BYTES=10
HEX: 0x8 0x0 0x14 0x0 0x25 0xE6 0x11 0x3B 0x0 0x0
-----End of Datagram-----
Received datagram.
-----Datagram----- BYTES=17
HEX: 0x8 0x0 0x18 0x1B 0x0 0x0 0x0 0x0 0x0 0x12 0x23 0x24 0x0 0x0 0x7B 0x0 0x0
-----End of Datagram-----
Received datagram.
-----Datagram----- BYTES=22
HEX: 0x8 0x0 0x7 0x0 0x3 0x4 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x64 0x0 0xD
-----End of Datagram-----

----------------snip------------------

Even if I am reading and writing on the bus, is it still possible, that my board is not working properly?

[bbqkees]

It looks like 0x18 is too short. It should be much more bytes.

[friedl100]

I have already thought so, so my question, if the board could be wrong?
But why does it work once at the start of the boiler?

[jeroenkl]

I have already thought so, so my question, if the board could be wrong?
But why does it work once at the start of the boiler?

I've got exactly the same issue. Still investigating.

[bbqkees]

I have already thought so, so my question, if the board could be wrong?
But why does it work once at the start of the boiler?

Did you capture a longer datagram for 0x18 at the start?

[bbqkees]

Does one of you have a Wemos D1 Mini lying around?
If so, load the firmware from https://github.com/proddy/EMS-ESP-Boiler/ onto it.
It has a much more advanced debug mode.

[friedl100]

Did you capture a longer datagram for 0x18 at the start?

Yes!
Captured at start:

-----Datagram----- BYTES=30
HEX: 0x8 0x9 0x18 0x0 0xD 0x1 0x77 0x64 0x0 0x0 0x0 0x0 0x0 0x83 0x0 0x7D 0x0 0x1 0x4D 0x0 0x1 0xD 0x30 0x48 0x0 0x0 0xFF 0xA3 0x0 0x0
-----End of Datagram-----

Captured whole day, two to three times:

-----Datagram----- BYTES=33
HEX: 0x8 0x0 0x18 0x0 0x26 0x1 0x77 0x64 0x22 0x9 0x1 0x7 0x0 0x83 0x0 0x7D 0x0 0x1 0x49 0x0 0x8C 0xD 0x2D 0x48 0x0 0x0 0xFF 0x2 0x10 0x80 0x0 0x0 0x0
-----End of Datagram-----

[bbqkees]

Ok looks good.
Can you try to request 0x18 with the other sketch?
maybe the boiler will send the complete datagram.

[friedl100]

Did you mean the EMSBusSimpleRegisterReadRequest sketch?

Request with length 17:

EMS bus request started.
Do request
Received a dataframe!
Correct frametype received.
-----Datagram----- BYTES=24
HEX: 0x8 0xB 0x18 0x0 0x26 0x1 0x7C 0x64 0x23 0x9 0x1 0x7 0x0 0x83 0x0 0x7D 0x0 0x1 0x4B 0x0 0x93 0x64 0x0 0x0
-----End of Datagram-----

With other length i only get:

"Received a dataframe!"

[bbqkees]

Not sure what you varied with the request length but the 24 byte response looks familiar.

So what you likely need to do is request 0x18 yourself every xx seconds.
You could mix both sketches together.

[friedl100]

I had to change the value in the code:

from
-----------------
registerRequest(INTERFACE_ID, UBA_ID, 0x18, 32); //This one reads 0x18 UBAMonitorFast from the boiler.
-----------------
to
-----------------
registerRequest(INTERFACE_ID, UBA_ID, 0x18, 17); //This one reads 0x18 UBAMonitorFast from the boiler.
-----------------

Thanks for the hint, i will try it but it will take a while, because i am not so familiar with Arduino coding!

[jeroenkl]

I like to read out my Nefit easy thermostat, but I do not know the RC code.
0x17,0x91,0x02,0x05, //#14 13 room temperature x 10
It isn't 0x17, anyone has experiences with the EMS tool and Nefit easy in combination?

[bbqkees]

I like to read out my Nefit easy thermostat, but I do not know the RC code.
0x17,0x91,0x02,0x05, //#14 13 room temperature x 10
It isn't 0x17, anyone has experiences with the EMS tool and Nefit easy in combination?

Can you send me PM?
I'm actually looking for someone with a Nefit Easy to work this all out.

[jeroenkl]

I like to read out my Nefit easy thermostat, but I do not know the RC code.
0x17,0x91,0x02,0x05, //#14 13 room temperature x 10
It isn't 0x17, anyone has experiences with the EMS tool and Nefit easy in combination?

Can you send me PM?
I'm actually looking for someone with a Nefit Easy to work this all out.

done!

[erhapp]

Unfortunately Buderus Logamax plus GB112 doesn't "speak" EMS. Does any know about a similar project for the older UBA1 (EMC) system? Is there any way to control my system?