Is there a need for the OpenTherm integration?

[yury-sannikov]

Have you looked for this feature in other issues and in the docs?
Yes

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Hi here.
I made an OpenTherm integration for my home project. I can be used with https://github.com/jpraus/arduino-opentherm or http://ihormelnyk.com/opentherm_adapter boards, but not with OTG.

Is there any interest in such integration so I invest some time to prepare a PR against the tasmota repo?

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Component code:
https://github.com/yury-sannikov/Sonoff-Tasmota-Dimmer/blob/8.2.0_local_ot/tasmota/xsns_85_opentherm.ino
https://github.com/yury-sannikov/Sonoff-Tasmota-Dimmer/blob/8.2.0_local_ot/tasmota/xsns_85_opentherm_protocol.ino

Also, have HomeAssistant complimentary component https://github.com/yury-sannikov/ha-mqtt-water-heater to wire it up if someone needed.

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none

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(Please, remember to close the issue when the problem has been addressed)

[nagyrobi]

+1 for this.

[majherek]

+1

[meingraham]

Any commonality with this PR that could be merged or development effort shared?

#8212

[arijav]

Any commonality with this PR that could be merged or development effort shared?

#8212

I see no overlap between my PR and OpenTherm, what I see is good a possibility to integrate inputs coming from the boiler into my driver. Getting the boiler temperature as well diagnostic data would be useful for the driver (have to check).

[yury-sannikov]

Agree with @arijav It's better to keep them completely separate. I think the best approach would be to use Rules to get PID output from telemetry and set boiler temperature based on it. I have a special command designed for the PID controllers. It does not write temperature to the Settings saving flash writes.

[arendst]

I would also like to keep the two seperate. Especially as OpenTherm will be rules based and therefore lightweight (I hope).

[ascillato2]

Just for reference for anyone searching in other issues, this was already requested in old issues at #2295

[arijav]

I would also like to keep the two seperate. Especially as OpenTherm will be rules based and therefore lightweight (I hope).

Yes, as I see my driver and OpenTherm are meant for different things:

1- Thermostat Driver: Is meant to act as a replacement or bypass of a feature reach room thermostat. It outputs a PWM to actuate heating valves for instance. Something like this: https://www.busch-jaeger.de/produkt/future-linear/knx-raumtemperaturregler-mit-tastsensor

2- OpenTherm: Is meant to act over the boiler, provide interfaces for telemetry data and commands (such set point). By the way, nice implementation @yury-sannikov

They can both complement themselves over rules. My driver can be used via a timer for setting the room temperature and OpenTherm for driving down the boiler if f.i. no heating is needed in the rooms or regulating the water temperature depending on the load.

Of course if there is need in OpenTherm of a PI to regulate the set point softly of the boiler I could provide an interface in the driver.

[yury-sannikov]

Of course if there is need in OpenTherm of a PI to regulate the set point softly of the boiler I could provide an interface in the driver.

IMHO, we can't foresee all the use cases ppl might come up with. One universal "interface" might be a telemetry output. So ppl can do something as I mentioned in the comment #8212 (comment) by setting up rules on the telemetry output.

https://tasmota.github.io/docs/Rules/#rule-trigger see

Tele-[SensorName]#[ValueName]

[nonyhaha]

Hello,
I am having trouble understanding a statement on the tasmota opentherm instructions page.
It say that: "The integration attaches ISR to the RX GPIO to avoid pooling. That GPIO should support interrupts. Please consider this while working on the schematics."

How should I proceed? If I tie something to gpio0, it will not boot. Should I use another gpio instead?

THanks!
L.E. I just used GPIO pins 4 and 5. I'll test it when I get home.

[PvdGulik]

Hello,

I'm very interested in this project. I would like to receive the open therm messages via MQTT. I have a OTGW with a nodemcu.
Is this possible with Tasmota?

Thanks