I am actually sitting here writing some firmware up for testing with a BME280 to compare with my DHT and BMP modules I have
I find the BMP280 sitting right next to one of my SHT31s is never more than a degree different, and typically within 0.2 degrees of each other. I have one BMP280 and 5 SHT31s across the house currently, all connected to their own D1 mini running ESPEasy; dealing with sensors is a lot easier on ESPEasy vs tasmota it seems.
a bit outside the box but I love the Xiaomi Bluetooth temperature sensor with display. You can get the reading via BT and HA on your RPi or using OpenMQTTGateway
I use the ecobee thermostat which has remote temperature/motion sensors. The sensors are relatively cheap. Right now, they are 39 USD for a 2 pack.
ouch.
I think I paid a total of $4 per sensor for my home made ones
flamingm0e - how do you keep the cost that low? Even with cheap boards like the ESP I find the cost to powering the device (usb adapters, etc) ends up making it over $10 min.
I just specced out a basic good accuracy sensor/accessories and yeah, around $10 is about the best I can do. If you shop around you might be able to shave off $1-$2 especially if you buy in “bulk”.
However I’m sure many people have a bin of micro-usb cables and USB wall chargers, so if those are free you can get closer to $7.
SHT30 Shield: $2.52
WeMos D1 ESP-12: $4.93
USB Charger: $1.58
USB Micro Cable: 1.88
Total cost: $10.91
I bought a bunch of Wemos D1 Mini boards from China a long time ago. The more you buy, the cheaper they are. I think they worked out to about $2.65 each. Same with the BMP180,BME/p/280,DHT11,DHT22. I bought a bunch of them (I don’t need shields or hats). I think they were about $0.65 each, and I have USB wall chargers and micro cables laying around.
Even if I had to buy the cables and chargers (buy in bulk and save), I would expect them to run about $1 each
Xiaomi sensor which are like $10 from gear best but look nice and work well, and last 6+ months on a single battery so installation is a breeze!
Second that. I have the old ones (round) and the new ones (square) which also measure atmospheric
pressure. I even have a couple of then inside my fridge :-). The downside of the xiaomi sensors is the need for a gateway and you can’t control when it will update HA. You can’t set a “refresh” rate. But they are cheap, battery can last longer than 6 months and you can just stick it (almost) wherever you want.
Do even the ones in the fridge last that long?
Do you have one in the freezer as well?
I’ve used mine for about 10 days now and the status message says that the batteries are supposedly down to 15% already.
how does the signal work being inside of a big metal box?
@finity, signal is good (that suprised me too). I have a gateway about a room of distance.
@chairstacker I didn’t put one on the freezer, but the one on the coldest shelf (about 4C ) is there for 3 months now.
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I’ve been recently looking to solve the same problem knowing that wifi is probably not very good for a battery powered component. I bumped into this https://www.instructables.com/id/LoRa-Tooth-Small-Wireless-Sensors/ and also https://www.aliexpress.com/item/nRF51822-Bluetooth-4-0-BLE-SOC-Temperature-Atmospheric-Pressure-Acceleration-Sensor-Module-Gyroscope-Light-Sensor-MPU6050/32816579479.html?spm=a2g0s.12269583.0.0.38cd131a4EysQH which seems to be programmable https://github.com/kasbert/nrf_beacon_itcpolyuhk
I bought both the ITC multisensor device and the purple https://www.aliexpress.com/item/Nrf51822-LIS3DH-Bluetooth-Module-CJMCU-8223-Bluetooth-acceleration-module/32821873481.html?spm=a2g0s.12269583.0.0.3ec758d8u9ZJfY
They haven’t arrived yet and haven’t started playing yet so I can’t advise any further!
What I do is get sonoff or Wion wifi controlled plugs and flash with tasmota and add dht11 or bme680. That way you have power taken care of and as a bonus have a switched outlet.
Hey buddy- do you fancy writing up a post on that temp sensor you created. Obviously the 3D printed case would be a bonus!
I could probably work on that this weekend.
I started using these in various colors of PLA:
I haven’t finished my own design yet, which will incorporate a wall charger into the design.
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Fantastic!! But deffo should be under share projects forum 