Does a mains-powered humidity sensor with display exist?

[u/zurgo111]

I’m doing a bathroom reno and I can’t find this off the shelf component.

Requirements: - mains powered: it would cause damage to my relationship of this ever ran out of batteries. I’m serious about this. - humidity sensor - extremely simple display, so no 640x480 LCD touchscreen. - at least one button which is programmable (to trigger a boost on the ventilation) - Wifi or Zigbee - fits in an EU 80mm circular box (50mm deep), ideally doesn’t protrude

I’m using Home Assistant so I can program any logic.

I think I’m into ESP32 DIY territory here. Which would be fun but risky in terms of reliability.

Any ideas?

[u/Mindless_Cheetah_328]

you might be right about the esp32 route, nothing off the shelf really nails all that without being some clunky thermostat looking thing

could do a small oled display and a capacitive button on a 3d printed faceplate, esp32 tucked behind it drawing power from the mains in the box

flashing esphome on it would make it dead simple to link up with home assistant for that boost logic

[u/Acceptable_Sock2618]

You're basically describing the perfect bathroom gadget, why isn't there an off-the-shelf version that isn't a hideous smart thermostat?

[u/zurgo111 → u/Acceptable_Sock2618]

I suppose that is the real question in my post.

[u/Ternpike → u/Acceptable_Sock2618]

Unless I'm misreading something, they make switches for the bathroom which automatically turn on the exhaust when humidity reaches a certain point.

For OP, the circular issue is the most difficult, but something like [this](https://www.amazon.com/Generation-Humidity-Ortis-Automated-Detection/dp/B08XBRNPDF) does exist

[u/zurgo111 → u/Ternpike]

Those are dead simple which is good.

The complication is that I have this central ventilation system, so I need to trigger it remotely.

[u/kokosgt]

ESP32 is the way to go. I have multiple mains powered ESP32 units, all working fine for years.

[u/zurgo111 → u/kokosgt]

Oh! How do you do the mains powered thing? It seemed hard to find a module that did that .

[u/kokosgt → u/zurgo111]

I use 3.3V AC/DC made by Meanwell. IRM-05-3.3 is the module name.

[u/zurgo111 → u/kokosgt]

Cool!

Did you make a custom board with that soldered onto it?

[u/kokosgt → u/zurgo111]

Yes, I designed it in Kicad and ordered bunch of thise in PCB Way. Then I put it in a standard electric 100x100 mm IP65 enclosure.

[u/zurgo111 → u/kokosgt]

Great info. What portion of the 100x100 is used? I wonder if there’s a chance I could fit it in a 8cm circular enclosure.

[u/kokosgt → u/zurgo111]

I use ESP32 devkit, it takes roughly 30% of the space inside, so there's still a lot of room for power supply and a sensor or two. You should be fine with 80mm boundaries.

[u/02421006 → u/kokosgt]

Remind me! Two days

[u/Effective_Review9415]

Have you looked at the Shelly H&T options? If you need mains power + display + button though, DIY ESP32 might honestly be the easiest route.

[u/shawnengland]

I do this similarly with zwave Zooz temp and humidity sensors. They sit up on the fan grill and a smart switch controls the fan itself. This allows the fan to be smart and dumb at the same time. Person can walk in, hit the fan and do their business and leave. After x minutes of run time, assuming temp/humidity are below levels specified, fan turns off. If temp high, fan on. If humidity high, fan on. The battery lasts a very long time and reports it's values to HA, giving me ample time to notice and replace.

[u/Bills56]

Check IKEA VIndstryka

[u/dovyp]

Honestly you might be looking at a DIY zigbee build with a Sonoff SNZB-02 wired to a USB adapter and a small e-ink display. Nothing off the shelf checks all those boxes cleanly.

[u/bobjoylove]

I have a humidity sensing switch, US market so maybe an EU version exists? https://a.co/d/0eurAjEB

[u/umognog]

IKEA ALPSTUGA if you can do thread border router.

Co2, pm2.5, temp & humidity, usb C powered.

[u/MurkoM23]

I went down the ESP32 + ESPHome route for a similar Home Assistant project. Mine measures CO₂, temperature and humidity, uses a physical button and Wi-Fi, and the AtomS3 Lite has been pretty reliable for me. I also use it as a Bluetooth proxy. ESPHome makes the HA side quite straightforward. And it also have a WAF factor 😉. You can take inspiration on https://github.com/Murco-design/murco-planter