Nah, just get one that can integrate with Home Assistant.
And deal with breaking updates happening on HA and the thermostat software itself while simultaneously maintaining api keys and policy changes every 2-6 months.
Its hard work.
You’re better off making your own thermostat relay controller
From my understanding, those days are in the past. I can’t speak to that from experience because I only recently got into HA.
Depends on what proprietary WiFi controller you purchased. The one I bought for my electric underfloor heating makes me manually request new api key every 6 months. So I’ve had to write ANOTHER script to automate requesting a new key via their website with selenium
Now theyve put a captcha in and ive since given up. I’m too old and busy for these games so I made my own janky looking ESP relay setup
Honestly, that’s how competent programmers look at just about everything these days, especially junky-ass websites that probably couldn’t violate more best practices if they tried.
Or mobile websites that ask you to install “apps”
I SWEAR it’s impossible to make fun of the selfhosting / hacking communities. I made a joke once that they should hack a toothbrush then I found they already did
Most programmers (those doing fancy GUIs and C# programming on a PC) would be seriously out of their league if they ever actually tried to program such a thermostat. Or any other embedded system. You really need a special skillset and hardware knowledge to even get a simple embedded system running. This is what my trainee just learned the hard way in the last weeks…
Except thermostats. You literally could do it with a Raspberry Pi, some 24V relays and a temperature sensors. Thermostats are not that hard.
Raspi is overkill. Mine runs off an esp32 using code I wrote in Arduino. The web interface takes up more space than the code. Only reason it’s an esp32 instead of an Atmega 328p is the wifi support
Smart thermostats do way more than just set the temperature: that’s just table stakes and of course easy. Off the top of my head the ecobee will:
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Set the temperature also taking the room’s humidity into account
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Communicate with sensors throughout your house
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Can change things via the Internet in case you accidentally forget to set it to a better temperature when you’ll be gone for a few days
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Tweak your schedule based on demand
I’m probably missing things, but they’re actually pretty useful, and I’m someone who thinks most IoT is shit.
Which are all things you can easily do with an RPi and some simple python. My response was to OP stating that embedded systems are hard.
If you’re using a specific embedded system and want to make it pretty, sure that could pose some issues, but if you want to make something functional that matches what a smart thermostat can do, there’s not much behind it.
Programmers love to oversimplify things; “do easily with an RPi and some simple Python” is kinda meaningless. Like, yes, an RPi is a general purpose computer and Python is turing complete, thanks.
For one, UI/UX is actually hugely important for a consumer device and definitely nontrivial, but on top of that, there is way more that goes into creating custom hardware than a bill of materials (which isn’t just saying “Raspberry Pi”) and choosing a programming language…
A thermostat is controlling a very expensive device that runs on a highly flammable gas that costs me real money to use. I want 0 serious bugs. I also want 100% uptime. A poorly made “smart thermostat” is way worse then the old school analog metallic ones imo. I also want my partner to be able to control the temperature in the house. These devices are actually not simple at all and I assume that’s the reason there isn’t a good open source/open hardware solution.
Embedded systems aren’t some mystical impossible thing - contrary to the previous commenter I actually find working with them easier then designing GUIs - but the commercially available devices are definitely nontrivial to recreate
Which are all things you can easily do with an RPi and some simple python.
Just like anyone can “easily” rebuild their transmission or patch a piece of leaky copper pipe or bake an apple pie from scratch or hit a bullese from 50 yards out.
What’s easy for you isn’t easy for everyone.
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All of that is handled by the HVAC (if there’s anything to handle) and not the thermostat
Thermostats can be (and most often are) a bimetallic strip that bends one way as it cools and bends the other way as it warms, and that flips some switches that you set for temperature ranges which then demands cool or hot from your hvac
That is the simplest possible thermostat and works great for setting a temperature, but that’s not the ideal thermostat. The temperature your house “feels like” also depends on humidity. You may also care about the temperature more in a spot further from the thermostat and getting accurate measurements in that location can save you money and waste less gas. There is also the decision of how long you should run a furnace and, in the case of multiple stages, which stage you should run, although some furnaces control the stages themselves. Then there is air flow. Controlling the fan separately is useful if the house doesn’t evenly heat. Sometimes you can just have the fan turn on more often and use the actual furnace less, saving gas again.
Also sometimes it makes sense to heat your house slightly more during high demand hours to save money. I dunno there is just a lot that could be done with an intelligent thermostat, it’s one of the few things that makes sense to make smart to me.
Those are all very nice things to have in an improved thermostat, I agree completely
The point I was replying to was making the erroneous claim that basic operation of an HVAC isn’t possible with an RPI thermostat because of things the thermostat doesn’t handle
Ah sorry yea agreed, at least for the units I know about
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I think what you’re failing to understand is that newer HVAC units are designed to be run in a specific way
Not missing that, as I and yourself said it’s done via the actual HVAC unit and not the thermostat
but without proper “eyes” the brains are useless.
No, the nicer features just don’t get used, it doesn’t make the entire unit not work
there’s just too much risk of things to go terribly wrong and multiple people literally die.
Lol, people aren’t going to die if you replace your thermostat with an RPI unless you wired the thermostat so poorly that you somehow manage to schock someone touching the thermostat
Again: thermostats just tell the HVAC to run and which part to run, any other advanced features are not required to be catered to in order to work. My brand new fancy schmancy heat pump with all those cool features listed runs off the same $2 Honeywell thermostat my old heater did, if I want the advanced features like zone sensing I can upgrade my thermostat, but my heat pump works without them just fine
Thermostats are Barney basic in function, touch the red to the hot to call heat, red to yellow for cool, and red to green for the fan, then open the circuit when the temp is where you want it. Kinda sounds like a fun project.
It’s actually surprising that we expect so much from a smart thermostat. Wouldn’t it be far smarter to sell a dumb thermostat on a local iot network and put the smarts in your automation hub? People who want the extra functionality would be good with that and people who don’t would appreciate saving the money
I could see that, but you have to remember that the average consumer doesn’t have an automation hub or get deep into the automation sphere, and as such many of these products are designed to be standalone devices that can be controlled from a phone. Often enough they can be the only ‘smart’ device in a home.
That all said, a dumb thermostat like your suggesting would still require a small CPU, ram, embedded OS, and network stack/hardware to operate and communicate, so I don’t know how far the savings would go. I can’t imagine the processing power on something like a nest is that powerful as it is.
My Ecobee not only has some fairly sophisticated software, a touch screen, and remote sensors, but enough CPU to run Alexa
I’d be curious to see what system resources are required for Alexa
I’m sure not much: Amazon is not likely taking a loss on all those $50 Echo Dots, but that’s a lot more than a thermostat needs. It’s also on WiFi and can play streaming audio, so that’s not nothing
I had no idea it was that simple! How do you control heat pumps? I know they have a setting where if outside is too cold it runs backup electric or gas.
Heat pumps are not simple at all. They are extremely efficient but can’t produce a large temperature gradient so they need to run very long cycles (potentially remaining on 24 hours straight). Modern cold weather air source heat pumps also tend to have variable output (variable speed compressor, variable speed fan). This demands a more complicated thermostat that adjusts the heat pump up and down, possibly with PWM.
And then there’s the emergency/auxiliary heating from the furnace. The thermostat needs to have some intelligent logic to decide when the heating demand exceeds the capacity of the heat pump and call for the furnace.
Heat pumps are an entirely different story, and I don’t have too much experience with them, most of the splits I’ve seen come with their own remote controls. I was talking on more traditional wall heaters, central air/furnace/forced air, etc.
If its a cheap crappy one, the compressor is on/off depending on temperature. Decent ones will have a VFD to manage the load of the compressor so it doesn’t have to turn on/off all the time but just regulates the compressor load to match heating/cooling requirement. Both have their own controls, and you generally shouldn’t mess with them.
Everything is laugh and giggles until the thermostat is turing complete.
I mean, as far as my mum is concerned, even setting up the TV channels correctly is “programming”…
