This is interesting as an example of just how complicated and elaborate a toolchain you can use to build something dead simple.
There’s a lot that comes for free by adding all these libraries and crates and steps. But from what I can tell it comes down to:
let _ = if fan_on { fan.set_high() } else { fan.set_low() };
klooj•Jul 11, 2026
iroh is a peer to peer networking technology so the project example of controlling a fan isn't so much about the fan but rather that it's controllable from anywhere through an esp32 microcontroller that can maintain a resilient connection endpoint even through power cycles and so on. I think iroh was posted about on HN a few weeks ago and I had a similar reaction of like...what in the world is this blog post even saying haha. But I found their docs page and found it pretty fascinating learning!
https://docs.iroh.computer/what-is-iroh
rwmj•Jul 11, 2026
I use a fan with an on/off button.
cinntaile•Jul 11, 2026
That's very much not a smart fan. Not really relevant.
rwmj•Jul 11, 2026
Pretty relevant because I've never seen the reason for "smart" gadgets at all. Physical switches are simply better.
bloppe•Jul 11, 2026
If your fan isn't Byzantine fault tolerant, you're irrelevant
embedding-shape•Jul 11, 2026
> Physical switches are simply better
Pff, assuming that everyone have arms and hands much?
Also I don't see the point of a fan, I live right next to the ocean, if you want moving air, why don't you just open a window?! Talk about useless invention
rwmj•Jul 11, 2026
I do have working arms and hands, so for the lights and fans in my house I don't need to assume otherwise.
kennywinker•Jul 11, 2026
90% of smart devices are for novelty, or for you to spend more time setting up and maintaining their automations than they save you in being automated.
But that 10% is magic. A fan that switches on when air quality falls below a threshold? Not that useful in a living room, but in a workshop setting - especially a shared workshop setting? Awesome. Just awesome.
A well defined use case, in the right setting, and smart stuff can be genuinely very useful. Usually that’s not how they’re used - i know, because of the 15-20 smart things i have only one or two are genuinely useful.
embedding-shape•Jul 11, 2026
> A fan that switches on when air quality falls below a threshold? Not that useful in a living room,
Why wouldn't that be useful? People be surprised how poor their air quality generally are inside, unless they already measure it, making it better sounds useful in oh so many ways.
> i know, because of the 15-20 smart things i have only one or two are genuinely useful.
What are those things? I have about 70-80 "smart things" by now, but every single one is genuinely useful, otherwise I wouldn't install them in the first place. Lots of open/closed sensors, soil moisture, temperature+pm2.5 sensors, water taps and so on.
kennywinker•Jul 11, 2026
> Why wouldn't that be useful? People be surprised how poor their air quality generally are inside
First because it’s the wrong solution to the problem. As I understand it bad air quality in a home is created by specific activities like cooking, vacuuming, or lighting candles/incense/smoking. So you solve the problem by turning on the fan when you cook, opening the windows when you vacuum, and by not using incense or smoking.
Second because you can have a dumb sensor and switch the fan on with your hand when it goes turns orange or red.
> I have about 70-80 "smart things" by now, but every single one is genuinely useful
We have different definitions of genuinely useful. I’m glad you find you setups useful tho - you do you!
victorbjorklund•Jul 11, 2026
And some people don’t see any reason for the internet and just wanna use phones and physical mail. To each their own.
kelnos•Jul 11, 2026
I have lots of smart gadgets that also have physical switches. It's convenient to be able to control them in more than one way, from more than one location.
Anyway, why are you commenting here if you're not into this sort of thing? Feels like you're just trying to stir up an argument.
miki123211•Jul 11, 2026
The reason is UI.
There's only a limited number of features that you can pack into a few buttons and a 7-segment display. If you want to sell outside the US and need to support the long-tail of non-English languages, preferably without per-country product variants, you can't even label the buttons any more, you have to rely on simple pictograms and icons.
If there's a $1 microcontroller in your device (and there often is), you're very tempted to implement lots of features which cost you almost nothing, but that kind of UI just doesn't really let you do so. Sure, you could add a proper touch screen with a localizable UI stack, with reflowable text and support for displaying Kanji and RTL languages, but that's often more expensive (and less practical) than slapping on a BLE or WiFi chip.
quickthrowman•Jul 11, 2026
You can have the best of both worlds with a hand-off-auto switch.
anon7000•Jul 11, 2026
Having the option to say “hey siri turn on the fan” while you’re in bed is pretty nice. This kind of thing works pretty reliably these days with the right setup. The fan still has a physical switch.
dtj1123•Jul 11, 2026
Can't help but read this in the voice of Homer Simpson.
kaashif•Jul 11, 2026
I think it's great someone is working on a fun little project such as a smart fan but let's not kid ourselves, it's not supposed to be practical! I don't think anyone would claim that.
It's a demo of how easy it is to make even an ESP32 device available globally with iroh.
aquariusDue•Jul 11, 2026
Works on Android too when developing Dart applications and making use of flutter_rust_bridge though it's a bit of an involved setup to be honest.
I really hope more people will play around with iroh and build stuff especially because in the last year some things have been renamed in the API to be more clear and other stuff has been simplified e.g. see this blog post https://www.iroh.computer/blog/iroh-0-94-0-the-endpoint-take...
miki123211•Jul 11, 2026
The hard part isn't controlling the fan, it's controlling the fan from anywhere, without a central server in the way.
Sure, you could probably make this much smaller if you invented a specialized p2p fan control protocol, but that's a lot of work.
quickthrowman•Jul 11, 2026
The simple way to do this is a dumb thermostat wired through a relay coil that enables a fan. It doesn’t give you remote access to change the setpoint but that’s all this setup does. Something like this has a setpoint you change once and then leave it.
Edit: actually, that's a Node.js-specific API. For browsers, it seems like they should have a platform-independent JavaScript/TypeScript API that includes a WebAssembly file (if needed) instead of expecting you to compile WebAssembly yourself.
nine_k•Jul 11, 2026
Not touching JavaScript might be a reason enough. (Though I bet it has a Typescript API, and Typescript is great.)
croes•Jul 11, 2026
Typescript is nothing without JavaScript
roblabla•Jul 11, 2026
With that logic, C is nothing without assembly.
embedding-shape•Jul 11, 2026
Does C also have a compiler that turns C code into assembly before the real runtime does its work? Never done much C development in the past, didn't get the impression it worked like that.
IceDane•Jul 11, 2026
You can output assembly with any toolchain, yes. But there's no runtime, at least if you mean in the sense that the code is executed by a runtime.
messe•Jul 11, 2026
> Does C also have a compiler that turns C code into assembly before the real runtime does its work?
What do you think ahead of time compilation is?
OJFord•Jul 11, 2026
> Does C also have a compiler that turns C code into assembly
Yes, that's 'a C compiler', like gcc.
> before the real runtime does its work
Sort of, the program is 'the runtime', but this is backwards, languages that have 'a runtime' get the name from it running at runtime to compile/interpret source or byte code. In C what runs at runtime is just your program, whatever you compiled. (Maybe it's an interpreter though!)
embedding-shape•Jul 11, 2026
I mean, once you split that sentence into pieces and answer them individually, of course it stops making sense. It's the whole "+ chuck the results into a runtime" that makes it make sense (or not) as a comparison against "TS > JS > V8/SpiderMonkey"
throawayonthe•Jul 11, 2026
a c compiler turns c code into assembly which is then consumed by an assembler(?)
croes•Jul 11, 2026
Typescripts add another layer on top of that
Teknomadix•Jul 11, 2026
Why.
Frenchgeek•Jul 11, 2026
Because Uncle Iroh needs more fans maybe? (should have been a tea kettle)
gurjeet•Jul 11, 2026
In hacker culture, the correct question is "Why not?"
Somebody wanted to do something, and they did it; it doesn't have to be any more complicated than that :-)
> Don't be curmudgeonly. Thoughtful criticism is fine, but please don't be rigidly or generically negative.
Someone with too much time on their hands might benefit from the iroh solution....
sunshine-o•Jul 11, 2026
iroh is very interesting and in many way it could get traction for IoT.
Now I am not sure it is feasible but it would be interesting to have it available in esphome. I feel this is really where real adoption happens.
devttyeu•Jul 11, 2026
Any plans to standardize Iroh IoT protocols, e.g. Matter over Iroh / Some other standard that would be plug-able to things like Home Assistant?
karissa•Jul 11, 2026
Yes, iroh here. We are looking into projects who want to use iroh with matter or thread. If you have a project you want to collaborate with our engineers on, please get in touch! Send an email to support@iroh.conputer
Liftyee•Jul 11, 2026
While this is neat, it strikes me as the software developer's idea of a "smart fan". The engineer in me says that an actual "smart fan" would be one whose blades are designed to produce maximum airflow with minimum noise (variable pitch? avoiding turbulence?)
lilhenry•Jul 11, 2026
He’s using a noctua fan which are pretty much the quietest pc fans you can buy while still moving large amounts of air
pessimizer•Jul 11, 2026
I think you're describing a "great" fan. A "smart" fan is one that thinks. e.g. smart TVs are worse (and therefore cheaper) than dumb TVs, but they do a lot more thinking.
unsolved73•Jul 11, 2026
Iroh is probably one of the best shots we have at making IoT finally secure with the built-in endpoint-to-endpoint encryption. The only thing that is missing is an embedded QUIC stack, the setup described in this article sees a little bit too hacky (4 MiB of PSRAM, really?).
In a heatwave, you need AC, not a fan. Moving hot air around without cooling it is pretty much useless.
Cthulhu_•Jul 11, 2026
But a fan is nice in not-heatwave but still warm temperatures. I have a usb desk fan from a PC cooler manufacturer (Arctic I believe) and it's one of the best accessories.
embedding-shape•Jul 11, 2026
Anything helps, when you don't have AC. Moving slightly colder air to where you sit, or moving away generated from your body, does make a ever so slight difference. Helps to get rid of some sweat too, if you're sitting and sweating, which also helps a tiny bit.
basro•Jul 11, 2026
A fan is better than nothing, even in a heatwave.
phoghed•Jul 11, 2026
Lived in the California desert with no AC as a kid, fans definitely help. Especially if you are sweating or spritz yourself with some water
lookeey•Jul 11, 2026
Fans increase the efficiency at which your body's own cooling system (sweating) works by increasing the amount of air that flows by your skin, be it hot or cold.
10 Comments
There’s a lot that comes for free by adding all these libraries and crates and steps. But from what I can tell it comes down to:
let _ = if fan_on { fan.set_high() } else { fan.set_low() };
Pff, assuming that everyone have arms and hands much?
Also I don't see the point of a fan, I live right next to the ocean, if you want moving air, why don't you just open a window?! Talk about useless invention
But that 10% is magic. A fan that switches on when air quality falls below a threshold? Not that useful in a living room, but in a workshop setting - especially a shared workshop setting? Awesome. Just awesome.
A well defined use case, in the right setting, and smart stuff can be genuinely very useful. Usually that’s not how they’re used - i know, because of the 15-20 smart things i have only one or two are genuinely useful.
Why wouldn't that be useful? People be surprised how poor their air quality generally are inside, unless they already measure it, making it better sounds useful in oh so many ways.
> i know, because of the 15-20 smart things i have only one or two are genuinely useful.
What are those things? I have about 70-80 "smart things" by now, but every single one is genuinely useful, otherwise I wouldn't install them in the first place. Lots of open/closed sensors, soil moisture, temperature+pm2.5 sensors, water taps and so on.
First because it’s the wrong solution to the problem. As I understand it bad air quality in a home is created by specific activities like cooking, vacuuming, or lighting candles/incense/smoking. So you solve the problem by turning on the fan when you cook, opening the windows when you vacuum, and by not using incense or smoking.
Second because you can have a dumb sensor and switch the fan on with your hand when it goes turns orange or red.
> I have about 70-80 "smart things" by now, but every single one is genuinely useful
We have different definitions of genuinely useful. I’m glad you find you setups useful tho - you do you!
Anyway, why are you commenting here if you're not into this sort of thing? Feels like you're just trying to stir up an argument.
There's only a limited number of features that you can pack into a few buttons and a 7-segment display. If you want to sell outside the US and need to support the long-tail of non-English languages, preferably without per-country product variants, you can't even label the buttons any more, you have to rely on simple pictograms and icons.
If there's a $1 microcontroller in your device (and there often is), you're very tempted to implement lots of features which cost you almost nothing, but that kind of UI just doesn't really let you do so. Sure, you could add a proper touch screen with a localizable UI stack, with reflowable text and support for displaying Kanji and RTL languages, but that's often more expensive (and less practical) than slapping on a BLE or WiFi chip.
It's a demo of how easy it is to make even an ESP32 device available globally with iroh.
I really hope more people will play around with iroh and build stuff especially because in the last year some things have been renamed in the API to be more clear and other stuff has been simplified e.g. see this blog post https://www.iroh.computer/blog/iroh-0-94-0-the-endpoint-take...
Sure, you could probably make this much smaller if you invented a specialized p2p fan control protocol, but that's a lot of work.
For specific applications like transfer fans for a server room with a small amount of heat to react, you can buy an all-in-one thermostatically controlled fan: https://acinfinity.com/room-to-room-fan-8-with-temperature-c...
https://docs.iroh.computer/languages/javascript
Edit: actually, that's a Node.js-specific API. For browsers, it seems like they should have a platform-independent JavaScript/TypeScript API that includes a WebAssembly file (if needed) instead of expecting you to compile WebAssembly yourself.
What do you think ahead of time compilation is?
Yes, that's 'a C compiler', like gcc.
> before the real runtime does its work
Sort of, the program is 'the runtime', but this is backwards, languages that have 'a runtime' get the name from it running at runtime to compile/interpret source or byte code. In C what runs at runtime is just your program, whatever you compiled. (Maybe it's an interpreter though!)
Somebody wanted to do something, and they did it; it doesn't have to be any more complicated than that :-)
> Don't be curmudgeonly. Thoughtful criticism is fine, but please don't be rigidly or generically negative.
Sincerely, HN Guidelines Police :-)
https://news.ycombinator.com/newsguidelines.html
It links to my Google Home installation and responds to voice commands.
https://us.store.tapo.com/products/tapo-h110-smart-ir-iot-hu...
Someone with too much time on their hands might benefit from the iroh solution....
Now I am not sure it is feasible but it would be interesting to have it available in esphome. I feel this is really where real adoption happens.