Wirsbo/Uponor thermostat replacement

[Denke]

Hi all
Here is my first mysensors HW that i developed and also my first post. Not all functions are tested at the moment.
I started by analyzing the current thermostat on size and function. Then i took all the info and started working with it in designspark.

My plan is to use this with Openhab

Spec
-Should be able to open/close valve in Uponor system
-Should in the future be able to open the valve from 0-100% (Think i need to change valves for this)
-Should fit in the Wirsbo thermostat mechanics
-The system shall fall back to "old thermostat" function if the home automation stops working by using the knob setting
-The system shall be built as much as possible on cheap components that could be bought on for example ebay

Old System

New system
If only on/off function is requested then the MOC 3023 could be replaced by a a new one with zero crossing detection and then also the zero crossing detector can be omitted (IL250 in the schematic)

Schematic

Result
The HW fits in the old casing
Not all components are mounted at the moment as i have not received them yet, but the board have partial functions

[Hoffan]

This was a nice project.

I have a lot of these wirsbo in my home. I hope this will work well

[Denke]

I hope so to.

At the moment i struggling with the best way to present this sensor to my openhab and also what is the best way to set it up.

Parameters in
-remote requested temp //temp requested by the home automation system/user (mandatory)
-hysteresis low, hysteresis high //where to open and close from requested temp point (Setting for the Tech user) 0.5 will be default
-Update time //how often shall i regulate/change and measure (Setting for tech user) 1min will be default

Parameters out
-Temperature
-valve state
-Info field:
--Direct requested temp (knob reading)
--Remote requested temp (See above)
--Running mode internal/external (fall back if no communication is reaching the thermostat, but thermostat info is visible in system)
--hysteresis set in thermostat
--Update time

Anyone got any thoughts on what is the best way to present this.

[bjornhallberg]

Fantastic project! I also have a ton of these Wirsbo thermostats (from circa 1999) at home. Some of them have failed and have been bypassed. Remarkably expensive to replace and remarkably dull design wise. I always wanted to build something like this, possibly with the addition of a small oled display and a 3d printed or cnc machined (wood) enclosure.

[Denke]

New boards ordered. Took the oportunity to add an extra connector for SPI. So this in combination with the SDA/SCA will make it possible to add an OLED.

[Denke]

Finally my new boards have arrived, made some mistakes on the first one.

[clio75]

Hi,
Nice project. I have started similar "upgrade".
But my plan is to have separate temp/humidity sensors that reports to the VERA.
And then have a separate controller that open/close the valves/attenuators.
Now I have some sensors connected. My next step is to create one arduino/MySensor PID controller.
This should get actual temp and setpoint from VERA.

For a fallback I have some Ideas.

• Use some Pre Programmed settings.
• Last PID settings
• Get information directly from each sensor. (setup from VERA)

Looking forward to follow your project :)

[Denke]

Now the code is tested against openhab2.0 after some work adding HVAC in the binding. Will make a pull request for the binding part soon

[Denke]

2 boards completely assembled and working as expected. 3 more to go after ordering the missing components. Now some last fixes to the code so that memory can be wiped by pressing a button and also the check if connected to the home automation system if not a fallback should be initiated

[bjornhallberg]

@Denke Any updates to this project? Did you deploy the sensors? Any issues or has it been smooth sailing for the last couple of years?

[Denke]

@bjornhallberg The sensors are working fine and have been installed in my home for the last couple of years. Some optimisation needs to be done to the code, that i have not done. This is more connected to understanding when the mysensors network is in "range" as i want to fallback on the manual knob if the mysensor network is inactive for some reason or if i sell the house and the controller goes with me.