oleg_tarasov

Actually I did exactly that :) I use ESPHome to control a gas boiler which heats my home. It's not without problems and required a lot of tinkering, but after the initial phase it required very little maintenance throughout the winter. This year I plan on adding an ability to control AC. https://news.ycombinator.com/item?id=40017176

Maintainability is a concern that I haven’t figured out yet :) Right now my plan is to replace my DIY thermostat with off the shelf device suitable for my boiler when we sell the house. All the advanced features will be lost, but this still is the average expected level of automation in the area :)

After I finished debugging the prototype, it required literally zero maintenance throughout the winter. Actually we were not living at the house at all, contractors doing remodelling work were living there instead. I installed a LCD screen with basic temperature controls and they had no problem with it whatsoever.

Doing this project from start to finish took me 2 or 3 months on and off, mostly during the weekends.

Doing it right yourself is the exact solution I arrived at myself :) I was shocked to discover how low the average technical level of local contractors is. I was super lucky to find a highly professional guy to overhaul the pipework, but anything more complicated I had to study on my own. Luckily, there is a ton of youtube videos, so the only thing you actually need is time.

Yes, safety and robustness were my primary concerns while designing this project. This house is more like a vacation home, and we don’t live there permanently. So my main goal is being able to control remotely as much of my heating system as possible, making sure not to burn the house down at the same time :) Here is what I took into consideration:

1. My device interfaces with the boiler through optocouplers, so I don’t touch boiler circuits with my crappy engineering skills.

2. The boiler itself, as well as OpenTherm protocol, seem to be able to recover automatically from many failure modes. It doesn’t matter much if some frames are dropped or mangled, since full set of control signals is repeated every couple of seconds.

3. I rewrote critical parts of OpenTherm component for ESPHome to make code more resilient to failure. The whole firmware is designed in a way that incorrect values or broken frames don’t bring anything down catastrophically. I also made sure that boiler has its own maximum temperatures set to sensible values, so that incorrect signals from the thermostat will be discarded.

4. The device is designed to be completely self-contained and doesn’t rely on Home Assistant or Wi-Fi being up.

There are a couple of things that I plan on adding to this setup, like a Shelly relay on boiler power input to be able to do a hard restart remotely.

Ideally, I would also prefer not to McGyver a custom device, but unfortunately, there are no such dumb smart thermostats for my boiler that would allow remote control.

Thanks for the context! I didn't research OpenTherm much, since my boiler is one of the most basic models on the market. It supports just the bare minimum from V2 spec, but it works, so I'm not complaining :) This boiler was already installed when we bought the house, so not needing to replace it was a great way to save some money for remodelling.

Otherwise, I completely agree that charging 3K for the spec is a stupid money grab. When the time comes to build a new house and choose a new boiler, my choice will be influenced by what protocols are available and whether I can control the boiler with my own thermostat.

I completely agree, using ESPHome beats writing firmware from scratch, even though lots of Arduino libraries are available. But the flip side is that ESPHome is in active development with lots of contributors, so sometimes things don't work as you might expect. And if that happens, your only option is to spin up an IDE and dive into source code :) For example, during this project I had to fork an abandoned OpenTherm library and rewrite almost half of it, as well as contribute a couple of bugfixes to ESPHome itself. It was actually fun, and I expected something like that from the beginning, but such a sharp drop from a cliff when YAML config doesn't work, will be a surprise for most people :)

Thank you for the suggestion! I will try to add some plots if data from winter months is still available in Home Assistant. Based on my observations during winter, room temperature fluctuation is usually ±0.3° C around target temperature, which I consider to be pretty good for a first prototype :)

This is actually a less creepy kinda useful application of face recognition (not taking into account actual face recognition for surveillance which is grossly unethical). The question is how does it fit into legal framework? As far as I know, many countries require retail staff to physically check your ID if they suspect you are underage.

It looks nice, I think I'm going to give it a try. But how is it different from Mermaid.js?

Actually, I completely agree on this one. Mysterious guy in a hoodie hacking your bank account while you enjoy your frappuchino waiting for a flight is much more easy to believe than someone stuffing your super-secure p@ssw0rd1 leaked from cat-lovers phpBB forum 8 years ago.