Outside temperature with SD18B20 does not work properly

[Clear]

Hi,
My NODO GateWay with Wemos1 has been running very well for more than half a year. Until now, the boiler had been used almost exclusively for domestic hot water. The home assistant integration and setting up the MQTT broker in HA were also quite easy. I also found an Otmonitor add-on by Bas Nijholt. This add-on enables the integration of the original Otmonitor from Schelte Bron into HA.

Well, before the heating season, I installed an outdoor sensor in the form of a waterproof DS18B20. It appears that it is measuring the temperature, although it updates somewhat infrequently. But then it gets stuck and only updates again after the gateway is restarted. HA usually has to be restarted to update the outside temperature. I hope you can help me.
I'm also not very familiar with MQTT and have searched a lot on the internet, but haven't found anything that helps me.

Here are my MQTT settings in OTGW.

MQTT-otgw.png (51.69 KiB) Viewed 1349 times

Here are my OTGW settings in Homeassistant.

HA-OTGW-Setting.png (32.55 KiB) Viewed 1349 times

Finally, I installed MQTT Explorer. But I can't find an MQTT message about the outside temperature there and it doesn't get me anywhere. I hope someone from the community can help me.
Thank you
Best regards
Clear

[hvxl]

There are two possibilities for connecting a DS18B20 to the OTGW: You can connect it to the PIC or to the Wemos. You only show information about the Wemos, which suggests that that's the method you're using. But then you don't have the "GPIO Sensors Enabled" option checked, which would be required to make it work.

So you'll need to provide much more details about how you connected the sensor. Also explain how you determine that "it gets stuck".

Finally, don't set AA=28 as a boot command. That will eventually fill the list of alternatives of the OTGW with lots of entries for MsgID 28. The OTGW stores this information in EEPROM, so you only have to do it once, not after each restart. And definitely not after each restart of the Wemos.

[Clear]

Hello Schelte,
Thank you very much for the answer and for your time.
I installed the DS18B20 according to the specifications in the "NODO-Gateway" documentation and "otgw.tclcode.com/peripherals.html".

SD18B20.png (152.92 KiB) Viewed 1274 times

TempSensor.png (114.92 KiB) Viewed 1274 times

I don't know whether it's connected to the PIC or the Wemos.
I'm a bit overwhelmed with the MQTT setting starting from "GPIO Sensors Enabled". Unfortunately, I didn't find a description of the necessary settings either.

MQTT-offen.png (42.36 KiB) Viewed 1274 times

I would like to add an overview of the debug information.

Debug_Information.png (76.02 KiB) Viewed 1273 times

I have a DeDietrich NANEO EMC-S 24/28 boiler that is not in the Equipment Matrix but it works to my satisfaction.
I don't have an OpenTherm thermostat but use an ON/OFF wireless room thermostat from Theben.
There is also an original outside sensor (which I don't have) from DeDietrich for my boiler that fits the variable control of the heating circuit flow.
If the outside temperature measurement works with the ds18B20 on the NODO-OTGW, what influence does this have on the heating behavior of the boiler?
Thank you again for your efforts
Clear

[Clear]

addition:
I forgot to explain how I can tell that the temperature is not updated or only updated very slowly.

reboot.png (35.63 KiB) Viewed 1261 times

The measurement does not change until the gateway is restarted.

otmonitor.png (49.19 KiB) Viewed 1261 times

The temperature is also displayed in otmonitor.exe after the gw reboot.

HA-OT-Monitor_addon.png (222.72 KiB) Viewed 1261 times

sometimes even rebooting the GW doesn't help. You then also have to restart HA.

HA-OT-Monitor_addon_HA-reboot.png (88.18 KiB) Viewed 1261 times

After the HA restart, the temperature is correct for the moment

otweb.png (50.17 KiB) Viewed 1261 times

In the OTGW web version, the outside temperature is never displayed.

I hope I have provided all the information here to identify the problem.
Thank you
Clear

[hvxl]

When using the Nodo shop OTGW with a Wemos or NodeMCU, there are really actually two distinct parts of the device: The stuff around the PIC, corresponding to the original OTGW documented on the otgw site, and the Wemos/NodeMCU, which is like a mini computer talking to the OTGW part via a serial connection. For the OTGW part, you can refer to the mentioned web site. For the Wemos/NodeMCU part there are several options for firmware to choose from. For this part you need to refer to the web site for whatever firmware you installed.

You used the method described on the OTGW site for connecting the temperature sensor. For that method, the GPIO settings on the Wemos/NodeMCU are irrelevant. So I'm going to ignore that part.

Temperature sensors connected to the OTGW are only used to report either the outside temperature or the return water temperature to a connected opentherm thermostat. You indicated that you are using an on/off thermostat, not an opentherm thermostat. In that configuration, the measured temperature does not normally show up anywhere. You can only see it in a PS=1 report. So I am actually surprised you get a few readings after a reset of the gateway.

As in many cases, a message log could help to figure out what really happens. I suspect there must be something requesting PS=1 reports. That could explain why the Wemos/NodeMCU web site never displays an outside temperature, even when OTmonitor does. OTmonitor processes the PS=1 output. The Wemos firmware by rvdbreemen probably doesn't.

As explained above, the temperature measured by a DS18B20 connected to the OTGW is only reported to the thermostat. So it won't have any influence on the heating behavior of the boiler. Even if I would change the code to make the OTGW send the value to the boiler as well, I doubt the boiler would behave any different. The thermostat is the intelligence of a central heating system. Normally, when a boiler has an outside temperature sensor, the thermostat can request that information and use it in its calculation of the control setpoint. The boiler itself doesn't use it, to my knowledge. That's why the sensor is optional.

[skippy]

Hi Schelte,

Been using OTGW with Lan interface in Domoticz for a number of years now and very happy. Used a separate DS18B20 with a NodeMCU to report outside temperature. Last couple of months I am transferring many of the Domoticz integrations to separate applications --> MQTT --> Domoticz.
So I build the Docker with OT monitor and MQTT to Domoticz, still all is well, apart that MQTT only reports when there is a change in a value, whereas the original Domoticz integration gives all values every 30 secs. That 30 sec report makes it possible to do a calculation of a daily average (in NodeRed), but still all is manageable
Yesterday I soldered the DS18B20 to the Nodo board so that I can use the NodeMCU for something else. Configured as per instructions and the correct value of the outside temperature was received after a PS=1 command in OT monitor. Then PS=0 to restart the standard flow of messages.
Outside temperature doesn't get reported although it changes over time.
Then I (re)added the OTGW via Lan hardware in Domoticz, this issues the PS=1 every 30 seconds and the outside temperature gets updated together with all other sensors. Stopping the OTGW hardware and issuing PS=0 in OTmonitor brings me back to a situation where only the changed values are reported (usually Boiler water temperature, Return water temperature, Delta T), but not the outside temperature.

Suggestions?

[hvxl]

The purpose of adding a temperature sensor to the OTGW is so it can return the outside- or return water temperature to the thermostat. If the thermostat doesn't request this information, there is not much use in adding such a sensor. With nothing asking about the measured temperature, it will not appear in a regular log and therefor OTmonitor can't report it. The PS=1 command is the only way to see it in such a situation.

I am considering a new feature where the OTGW will send the outside temperature to the boiler when you issued an AA=27 command and a temperature sensor is connected. But that will need to be developed. I don't have a target date for it. It is unlikely to happen soon.

[skippy]

Hi Schelte,
That makes sense, I was already a bit reluctant (but I like experimenting) to try this, because according to the equipment matrix the combination of my boiler (Intergas HRE) and thermostat (Honeywell touch modulation) don't report outside temperature.
So for now the PS=1 issued by Domoticz will do and perhaps your AA=27 solution will provide me with a new challenge when released.
Thx for now.