OpenTherm binding

[Jan-Willem Spuij]

Hi Guys,

Just a quick heads up: I've started working on a binding for the OpenTherm Gateway. The OpenTherm Gateway is a device designed by Schelte Bron, and sits between an OpenTherm Boiler and OpenTherm Thermostat. You can build it yourself, but there are sites now where you can buy a pre-assembled device. It communicates over a serial interface, though there are versions now with USB interface or network interface (through connecting a serial to ethernet converter). With it you can read a lot of status info from the boiler, control the thermostat (override temperature setpoints, control domestic hot water options, provide outside temperature for modulation calculations) and the boiler (CH water temperature, return water temperature, modulation level etc) and many more. 

We all love the Nest intelligent thermostat, but it only works with ON/OFF boilers, not with OpenTherm boilers that are common in Europe. Now I can have my original thermostat controlling the modulation level of my boiler and calculating the heating curve based on the outside temperature that comes from a sensor connected to openHAB. In turn I control the thermostat to make it smart, e.g. the schedule and presence detection come from Openhab to set the thermostat temperature setpoints). 

I love the Nest especially for the design, I almost bought the ICY thermostat because it's the smartest OpenTherm thermostat available, but there is nothing better than building the ultimate thermostat yourself of course...

The original gateway site is at: http://otgw.tclcode.com/

The Opentherm Gateway thread on domoticaforum.eu: http://otgw.tclcode.com/

Code is at: https://github.com/jspuij/openhab/tree/opentherm-gateway

Cheers,

JwS

[Herman van Horssen]

Hi Jan-Willem,

This is also on my todo list, I have an OT gateway and I am the process of setting up OH.

So if you need a tester or other help, just let me know.

My Java skills are low, but willing to learn.

Regards,

Herman

Op maandag 7 oktober 2013 09:17:53 UTC+2 schreef Jan-Willem Spuij:

[Eugene Schava]

Guys,

I don't know if it could help but I have bunch of scripts developed by me for my ON-OFF boiler. It checks current temperature and switch boiler on or off depending on current program

The most important part of it is procedure parsing program specified as string, like

Mon,6-21,8-19,18-21,23-19,Sat,6-21,23-19

which means have 21C at working days from 6 till 8 and from 18 till 23, and from 6 till 23 at holidays. Otherwise there should be 19C

So if it could help - I'll be glad to share it with you

Понеділок, 7 жовтня 2013 р. 12:12:10 UTC+3 користувач Herman van Horssen написав:

[Jan-Willem Spuij]

I'm afraid that your scripts are quite different from what this binding will do:

- The gateway controls temperature itself. Even more specifically, it let's the thermostat control temperature. In turn the gateway controls the thermostat override variables. So we set the temperature by telling the gateway to override the room setpoint (in 1/10th degrees celcius). There is no ON/OFF anymore.

- Scheduling will be achieved by normal scheduling using openhab rules. (or the gcal binding or something).

But thanks anyway. Anyway, for the people waiting on this binding, I've implemented 12 of the 55 frame types. When all 55 are completed, every message between the thermostat gateway and boiler can be parsed. Next would be implementing binding logic so we can send events to the items based on the received frames.

Finally sending / converting commands needs to be implemented so we can control the gateway.

Regards,

JwS

Op maandag 7 oktober 2013 12:13:38 UTC+2 schreef Eugene Schava:

[form...@gmail.com]

Hi Jan-Willem,

Any update on this?

Need some help?

I just build my own otgw and is running fine now (without openhab).

Recently I moved my stuff (rfxcom, zwave, elv max) to openhab and I want to use the opentherm as well

Regards,

Bjorn

msn/skype: b_langenberg AT. hotmail.com

Op vrijdag 11 oktober 2013 00:24:09 UTC+2 schreef Jan-Willem Spuij:

[Jan-Willem Spuij]

Actually, I'm quite swamped with regular work, so I haven't done much. Rougly 30 to 40 % of the frame types is implemented atm. At least I've completed the complete path from gateway to openhab item for the room temperature variable. I'll try and get the override setpoint function implemented this week so it can actually control temperature. That would be a nice start. From that moment it's more or less straitforward implementation (more of the same), so help is more than welcome then.

JwS

Op woensdag 6 november 2013 19:35:21 UTC+1 schreef form...@gmail.com:

[Charles Simms]

hi

I am a java developer and would be very interested in helping. I'm going to get familiar with developing bindings soon and I'll read the spec on OpenTherm so if you need any help let me know.

Charlie

[Vanisher]

Any progress on this one?

I have an opentherm device assembled.

Op donderdag 16 januari 2014 14:29:20 UTC+1 schreef Charles Simms:

[Thomas E.-E.]

Hi,

would you mind sharing your current status in on of your forks?

Is probably a better starting point than nothing :-)

Best,

Thomas E.-E.

[avdl...@gmail.com]

I've found Jan-Willem's development repository at https://github.com/jspuij/openhab and will be trying to work from his foundation. 

Ard

[jon.k...@gmail.com]

Anybody know if Jan-Willem managed to do any more work on the Opentherm gateway binding? Or if the already completed code is available somewhere? Unfortunately the link https://github.com/jspuij/openhab doesn't seem to work anymore, just redirects to a general OpenHab repository page.

Hope someone can help on this, would be great to link up Opentherm gateway to my Max! controlled radiators to create a multi-zone heating system...

Jon 

[Robert van Bregt]

Any progress/update?

(The link to  https://github.com/jspuij/openhab does work currently)

Op woensdag 12 november 2014 23:05:48 UTC+1 schreef jon.k...@gmail.com:

[bernard Rodriguez]

Hy guys ,
Just Sharing some info  about openhab OTGW integration .

I found a nice project which allow you to control  OTGW via MQTT  , so also from openhab via MQTT-Binding.

https://github.com/githubcdr/opentherm2mqtt

I supose most of you guys already figured this out .

Cheers

Bernardo