no, but i have one in the house
everything started last year when i was in china and i saw a floor register with motor to open or close
The manufacturer ask me to make a remote control from his cheap thermostat.
When i saw it, i was deceived , and i said i can make a better one.
I took the manual of mine and found the right processor to do the job, found a cheap LCD manufacturer, 1,75 $, found the cheap radio transceiver 2.3$ per piece and start programing
Everything works fine but i got stuck with the battery problem
On mine, i change the battery maybe 1 to 1 and 1/2 year or longer
After a made the first radio control one working , i stopped and decided to make first the thermostat, sell it, then develop the attachment for RF
It is not WiFi, it is just RF. My foal was to make one central unit on the main floor, have one individual thermostat on each room, and when in the room the vents are closed to send data to the main CPU
When all the vents are closed, then i stop the heat or cool.
When first room ask for heat or cool , i start the furnace or AC
In this way i save energy as the furnace or ac will run shorter.
I think i have a movie on you tube i posted for the guy to show the progress, but i have to find the link
One smart guru told me it will not work in a home due to back pressure ????
But is similar when i go in vacation and close all the vents in the some rooms , leaving just one open in the room with thermostat.
I do not know HVAC, but when i return from vacation, the house is still there and i did not see any damages from what ever back pressure .
I will send you the link when i find them

 

this is the first generation, with standard 4X20 lcd
Now i have a graphic custom LCD like that , and of course a proper PCB with SMD only
On the LCD you see all the segments on but i turn them on or off as necessary like for C or F

 

Very interesting.

The back pressure isn't a big problem. It will lower efficiency considerably.
Furnace will cycle on high temperature limit.
AC will freeze up. Needs lots of air moving to be efficient.
Heat-pump as I have, even more so.

Logic could be built in to only close one or two at a time.

As far as the thermostat goes, if relays are off the table, ac fets driven direct from controller with common ground is the best I can come up with.
No one has objected.

Devil will always be in the details.
Heat anticipation?
Some furnaces use thermostat on the micovolt line to gas valve.
Heat-pump thermostat needs 2 stage with + & - logic reversing valve driver.
These are just minor details. No thermostat will be universal.

 

I do not intend to make it universal
Just for standard furnace/ac, no heat pump
Also, the control of furnace or ac is done at the furnace level by the original control board
I just supply a request for heat or cool by replacing the 4 wire thermostats with mine
For furnace is transparent as it does not know who is in the other end.
Please send me a link if you have to read about back pressure.
There is an air flow switch which control when heater or cooling starts ?
How it works ?

 

The classic way a gas furnace is controlled.
On falling temperature, thermostat closes circuit opening gas valve. White wire.
Temperature in plenum rises until fan upper set point.
Fan starts. Continues to run until plenum temperature drops below lower set-point.
If not enough airflow, temperature continues to rise until high temperature limit shuts off gas valve.

In cooling mode.
Thermostat Connects Yellow to Green.
On rising temperature yellow pulls in condenser unit contractor, starting compressor.
Green pulls in fan relay to start fan. Often at a higher speed.

High efficiency furnaces often use electronic timers to control fan, purge, ignition, and other things.

I'll look for link later. Do a search for static pressure and how it relates to efficiency.