OTGW - Home Assistant Integration

[repressed-geek]

Hi Robert,

Thank you for all of your work, you've obviously spent a lot of time working on this!

This is likely to be a terribly noob question....

I have a Nodoshop OTGW with NodeMCU. I downloaded your firmware to the NodeMCU, connected it to my network and plugged the board into the OTGW. I can access the GW via the web portal and get the Home Screen. I have also updated the PIC firmware to v5.1

I have tried to add the OTGW as an integration on HA but every time I try to add the integration it tries for ~10 secs and then states 'Failed to Connect'. I've tried restarting both but can get no further. Have I missed something? Any assistance would be very gratefully received.

Kind regards,

Tom

[rvdbreemen]

Hi Tom

Mqtt is reconnected every 10minutes. I’d it cannot connect after 3 tries.

Just a few questions:

1. Do you have MQTT running with your Home Assistant setup?
2. Did you setup the MQTT broker on the settingpage?
3. Have you connected to your broker with an MQTT client (for example MQTT Explorer)?
4. Can you capture some debug logs for me?

Let me know what you find,
Robert

[rvdbreemen]

Well, that looks like you are now receiving messages on you MQTT broker. Did you configure Home Assistant to point to your broker too? If so, you should see the OTGW device as a discovered device.

[repressed-geek]

The OTGW comes up as a device on the MQTT Integration. The individual OpenTherm elements show up as Binary Sensors and Sensors on the overview.

[repressed-geek]

But the OTGW does not show up as a discovered device.

[rvdbreemen]

Could you check this for me:

1. Goto settings in Home Assistant
2. Goto integrations
3. Goto MQTT integration

At this point you should see one device (at least). If you only have OTGW you will see 1 device and 65 entity’s.

Let me know what you see please.
Robert

[repressed-geek]

Yes I have 1 device and 65 entities.

[sjorsjuhmaniac]

@repressed-geek in your opening post it sounds like you installed the OTGW INTEGRATION in HA, is that correct? If yes, please remove it. This only works with the 'traditional' nodeMCU firmware named easyESP

Based on the mqttexplorer screenshot I would say the HA Discovery is successfull (see all topics created under 'homeassistant'). Your HA screenshots also confirm you have the entities.

The problem seems to be that there is not 'otgw data' received, there is only 1 topic under 'OTGW'. there should be many more if the otgw is connected to the boiler.

so some questions:

• is the otgw connected to both the boiler and the thermostat?
• do you see any 'live' data on the webUI/webpage ON the nodeMCU "OTGW-Firmware"?
• please share the config settings on the nodeMCU "OTGW-Firmware"
• when you are 'viewing' with mqtt explorer, do you see ANY data coming in at all? Does the 'x message' after "OTGW" change at all?

[sjorsjuhmaniac]

I have tried to install the OTGW integration, I hadn't been able to. It seems from your comment that I never needed the integration which is likely where I've been going wrong. I had assumed that I had.

@rvdbreemen, maybe something to specifically add to the wiki/readme?

I have disconnected the OTGW from the boiler because I don't have the Evohome OpenTherm bridge yet and it overrides the BDR91 currently controlling my boiler (the house was quite chilly). When I did have it connected I could read the OT data from the boiler.

I thought the BDR91's send OT signals? I'm guessing it doesn't if you're waiting for an OT bridge ;)

NodeMCU Firmware Version0.8.1+92f10cb (14-03-2021)
OTGW PIC Firmware Version5.1
Compiled on (date/time)Mar 14 2021 14:56:26

Let us know if this issue persists when you have all the hardware setup as it should.

[repressed-geek]

Thank you both for your help. I think that I'm there now!

@rvdbreemen, I have updated the firmware, thank you for all your work on this.

@sjorsjuhmaniac, BDR91s are simple relays. OT bridge required. There's a long debate on the Evohome Shop forums as the Viessman boilers don't set a max flow temperature (and it isn't possible for the owner to do this), a user called Bart has written code to use the OTGW to force this (otherwise the boiler forever goes like the clappers and overshoots room temperatures). I wanted to get the OTGW in and working before getting the bridge.

@rvdbreemen is it possible to override command values in the OTGW (and thus to the boiler) through home assistant or would I need to edit the firmware?

[sjorsjuhmaniac]

Could you copy/paste or create a gist of that code? i'm curious but it's a closed forum. Where is this 'code' executed?

Please elaborate on what you mean by 'override command values'?

[rvdbreemen]

You can write commands to OTGW thru the MQTT command topic or REST API.

Or you could even make a plug-in in this firmware to execute your logic.

Please share the code from the other forum or even join our Discord server to chat about this, right here: https://discord.gg/gRVUQBKHbp

[repressed-geek]

I definitely need to be more careful with my language! The user has edited the firmware to limit the max boiler temperature.

_I've managed to build the gateway firmware with a small and quick modification so that it treats the #57 command in the same manner as the #25 command. This disables the functionality of changing on the wire a write request of the thermostat of the CH max temperature, for sure this shortcoming can be improved upon but since I don't see evohome sending out this command as a write data command (only a read data is done from evohome to the boiler) the hack suits my purpose quite well.

And it works.

I can now override the #57 command response using SR=57:65,00 to pretend that the maximum boiler temperature is 65,00 degrees. Evohome then scales the control setpoint between some minimum and the fake maximum temperature of 65. Log extract:_

22:04:35.399535 Command: SR=57:65,00
22:04:35.440532 SR: 57:65/0
22:04:37.903679 T80190000 Read-Data Boiler water temperature: 0.00
22:04:38.195700 BC01942CD Read-Ack Boiler water temperature: 66.80
22:04:38.437733 T90014C00 Write-Data Control setpoint: 76.00
22:04:38.706759 B50014C00 Write-Ack Control setpoint: 76.00
...
22:04:58.382856 T80190000 Read-Data Boiler water temperature: 0.00
22:04:58.718843 BC019434D Read-Ack Boiler water temperature: 67.30
22:04:58.925945 T90014C00 Write-Data Control setpoint: 76.00
22:04:59.217079 B50014C00 Write-Ack Control setpoint: 76.00
...
22:05:02.716139 T80190000 Read-Data Boiler water temperature: 0.00
22:05:03.039131 BC019434D Read-Ack Boiler water temperature: 67.30
22:05:03.262193 T90014C00 Write-Data Control setpoint: 76.00
22:05:03.545155 B50014C00 Write-Ack Control setpoint: 76.00
...
22:05:07.576364 T00395000 Read-Data Max CH water setpoint: 80.00
22:05:07.885404 BC0395000 Read-Ack Max CH water setpoint: 80.00
22:05:07.905126 AC0394100 Read-Ack Max CH water setpoint: 65.00
22:05:08.125435 T00394100 Read-Data Max CH water setpoint: 65.00
22:05:08.385432 BC0395000 Read-Ack Max CH water setpoint: 80.00
22:05:08.391833 AC0394100 Read-Ack Max CH water setpoint: 65.00
22:05:08.655487 T00394100 Read-Data Max CH water setpoint: 65.00
22:05:08.890453 BC0395000 Read-Ack Max CH water setpoint: 80.00
22:05:08.910505 AC0394100 Read-Ack Max CH water setpoint: 65.00
...
22:05:10.808619 T80190000 Read-Data Boiler water temperature: 0.00
22:05:11.066606 BC019434D Read-Ack Boiler water temperature: 67.30
22:05:11.352594 T90013E00 Write-Data Control setpoint: 62.00
22:05:11.562626 B50013E00 Write-Ack Control setpoint: 62.00
...
22:05:12.990673 T80190000 Read-Data Boiler water temperature: 0.00
22:05:13.224551 B401943CD Read-Ack Boiler water temperature: 67.80
22:05:13.519715 T90013E00 Write-Data Control setpoint: 62.00
22:05:13.719756 B50013E00 Write-Ack Control setpoint: 62.00
...
22:05:10.808619 T80190000 Read-Data Boiler water temperature: 0.00
22:05:11.066606 BC019434D Read-Ack Boiler water temperature: 67.30
22:05:11.352594 T90013E00 Write-Data Control setpoint: 62.00
22:05:11.562626 B50013E00 Write-Ack Control setpoint: 62.00
...
22:05:12.990673 T80190000 Read-Data Boiler water temperature: 0.00
22:05:13.224551 B401943CD Read-Ack Boiler water temperature: 67.80
22:05:13.519715 T90013E00 Write-Data Control setpoint: 62.00
22:05:13.719756 B50013E00 Write-Ack Control setpoint: 62.00
...
22:05:18.391972 T80190000 Read-Data Boiler water temperature: 0.00
22:05:18.702003 B401943CD Read-Ack Boiler water temperature: 67.80
22:05:18.918069 T90013E00 Write-Data Control setpoint: 62.00
22:05:19.206057 B50013E00 Write-Ack Control setpoint: 62.00
...
22:05:22.709280 T80190000 Read-Data Boiler water temperature: 0.00
22:05:23.036279 BC01942CD Read-Ack Boiler water temperature: 66.80
22:05:23.253401 T90013E00 Write-Data Control setpoint: 62.00
22:05:23.527313 B50013E00 Write-Ack Control setpoint: 62.00
...
22:05:28.122525 T80190000 Read-Data Boiler water temperature: 0.00
22:05:28.381581 B401940E6 Read-Ack Boiler water temperature: 64.90
...
...
22:08:09.569913 T00394100 Read-Data Max CH water setpoint: 65.00
22:08:09.754827 BC0395000 Read-Ack Max CH water setpoint: 80.00
22:08:09.770608 AC0394100 Read-Ack Max CH water setpoint: 65.00