Hey all,
A couple of weeks ago I posted my 3D printable pegboard organizers, and today I’m releasing the Only Sensor line of home automation sensors.
Fully free and open, complete with wiring diagrams, cases, component bill of materials, and instructions for assembly.
You source and build them yourself, with acquisition costs ranging from $2-$35 to build, and options for:
- mmWave presence
- PIR motion detection
- Temperature
- Humidity
- LUX
- PM <10µm AQI
- PM <2.5µm AQI
- PM <1µm AQI
- NOX
- VOC
All integrate with Home Assistant via ESPHome.
All the details can be found at: https://nowsci.com/only-sensor/
Those dht11 sensors are garbage tho. Best case they are wildly off on their humidity sensor. Worst case they keep breaking and shows nonsense readings. I would recommend bme280 sensor instead. If you read about them you might see people complain that they are reading too high temperatures, but in my experience its because they are misconfigured. Default settings have a very high sampling rate of multiple samples per second that heats up the sensor a tiny bit giving you the offset. Lowering the sampling rate or turn the sensor off completely in between readings gives really precise measurements on both temperatures and humidity.
+1 on BME280 vs the DHT. I don’t know why the DHT are so expensive, they’re pretty bad.
Yea I’ve considered recommending thr DHT22 instead, but I was trying to keep costs as low as possible, and honestly I’ve had pretty good results thus far (calibrating with other systems, anyway).
Bme280 is actually just as cheap if not cheaper than the dht sensors. But its a fair point trying to keep the cost down. I definitely like that philosophy, but if the quality suffers too much it’s just not worth the trouble. Keep up the good work. 😎
Oh good to know, will investigate!
This is some peak Lemmy. Thanks for the good work!
Cool. A few years ago I made similar sensors (but just PIR, LUX, esp8266 board, jumper wires, and some with ultrasonic proximity). Attached them to the wall with those 3m velcro things. ESPHome makes things so easy; didn’t even have to write code. Hardest thing was designing and iterating over the case to get the tolerances just right.
Very nice.
It’s missing CO2, but those are expensive so that’s understandable. If you need one of those, I think https://www.airgradient.com/ is a great choice.
I’ve had another user say the same thing, so I’ve considered investigating CO2. What’s the rationale to you for wanting it?
Not speaking for Mr Lemon, but for me CO2 levels are an interesting metric to trigger my air exchanger / HVAC fan combo for in a given zone, since it indicates stale air in general.
Same ^
CO2 sensor for me is the most important.
Good to know, maybe I’ll add a MH-Z19.
I don’t have HVAC, so I’m just using it to see when the air at my desk is getting stale so I remember to open the window. I mostly use homeassistant for the configuration, although I might also set up a notification at some point (I only got my sensor 2 days ago)
Interesting. The AirGradient sensors are exactly what I’m trying to avoid with the OS, considering their price tag. MH-Z19 sensors might be a good direction for me to go.
The neatest part of this is finding out about GAM.
Hah, yea I released that at the same time as WinApps so it didn’t get as much fanfare. Glad you like it!
Pretty sweet script, I might fork and see if I can adapt it to my Forgejo instance.
Oh man would love a PR for that if you’re willing. Been wanting to add Forgejo (and maybe GitLab) for a while now, and considering a rename to Git Application Manager.
If anyone like me is wondering what:
- PM <10µm AQI
- PM <2.5µm AQI
- PM <1µm AQI
…means it’s air quality. These measurements are referring to different sizes of particulate matter (PM) and their corresponding Air Quality Index (AQI) value
Yup! The ESPHome config also converts these into a standard AQI that you’re used to seeing.
Amazing! This is great work!
Thanks! They were fun to build and design for sure.
you will need to update the firmware on the LD2450. You do this with a mobile app called HLKRadarTool
Does this seem sketchy to anyone?
It certainly did to me when I made these. I ended up using an old Android phone for that part, but many members of the ESPHome community working with these sensors use it and have never reported a problem. HLK are the original manufacturers of the LD radar chips.
No, why?
Because DFU exists. We shouldn’t need an idle Bluetooth radio and proprietary arbitrary code execution to update the firmware on a device.
There are so many unnecessary attack vectors involved in this process, it should raise some red flags.
Hey now! The only sensor I’ll need is actually 4?! /jk
This is awesome!
Thanks!
This is incredible!
Thanks!
Man, I wish this had been a thing ~8 months ago when I was building these for my stuff.
…mine are awful, and these look awesome, so maybe it’s time to re-do that.
Weellll… In usual fashion for my projects, I made these about that long ago, just tested them for a long time before doing the write-ups.
