Simulate Thermostat with Gateway

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FreddyFFM
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Simulate Thermostat with Gateway

Post by FreddyFFM »

Hi,

I am pretty new to this forum and Opentherm. I received my OPTG from Nodo last week and installed it successfully at my Calenta ACE 25 (connected to the R-BUS in the front flap). The OTGW is not connected to any Thermostat as I have to put complete new wires to the living room (Bridge the contacts of the Thermostat connector at OPTG).
The Calenta came with an eTwist Thermostat connected in the heating room (which definitly makes no sense as I found out - so I disconnected it from the R-BUS for CIRCA).
Currently the Calenta runs dependent on the outside temperature. To hopefully run it more efficient my idea is to use my already existing Zigbee sensor for temperature and house automation tablet for temperature setpoint via the OTGW. But any way to send a command via REST API or MQTT did not show any affect to the values.

So two questions:
1. Is this simulation of an thermostat possible
2. How do I send the commands that they are accepted and used from the boiler (so that I can switch from OT depenedent to automatic mode)

Thanks for your help

Freddy
hvxl
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Re: Simulate Thermostat with Gateway

Post by hvxl »

As you neither disclose what you send nor what the response of the OTGW is, it is impossible to guess what the problem may be.
Schelte
FreddyFFM
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Re: Simulate Thermostat with Gateway

Post by FreddyFFM »

As I wrote, I would like to send the current temperature, measured by a ZigBee Sensor in the Living room (as far as I understood MsgId 24) as well as a temperature sensor I can adjust via a tablet (MsgId 16). I had a look on http://otgw.tclcode.com/firmware.html#operation but did not found commands to send these values. Are they just not described there? If it is possible how does the command has to look like?

I already tried to use the IDs like

Code: Select all

.../api/v1/otgw/command/24 with body value 20
or the Labels like

Code: Select all

../api/v1/otgw/command/Tr with value = 20
.

In both cases I got the response vor SE (Syntax Error)
hvxl
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Re: Simulate Thermostat with Gateway

Post by hvxl »

It looks like you are using the NodeMCU firmware created by rvdbreemen. That is not described on my site (otgw.tclcode.com) because it is a project by someone else. Documentation of the REST API can be found on his github.

By the way, you shouldn't expect that anything will happen by sending the room temperature to the boiler. A thermostat is more than just a temperature sensor. It controls the boiler by specifying a control setpoint, which is the desired water temperature, as well as some other bits and pieces. Boilers mostly ignore the room temperature and room setpoint messages. The designers of the ones that don't probably misunderstood the opentherm specs. To simulate a thermostat you have to implement a complete temperature control algorithm (usually done in the form of a PI(D) controller).
Schelte
FreddyFFM
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Re: Simulate Thermostat with Gateway

Post by FreddyFFM »

Thanks for your explanation. I saw that nodo firmware is different from yours but it at least uses the same commands.
My thoughts till now were that the Remeha takes care of the calculation when sending in a room temperatur (there is a setting: control heating automatic/based on outside/temperatur/based on room temperature/based on ot & rt). It look's like i was wrong in that thinking. At least - as I do not want to build it on my own I will try to wire the etwist which came with the heating to the living room (manual states to put in the most frequently used room).
Thanks for the support so far
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