really interesting. my understanding is that zigbee has quite a bit more range than bluetooth, is that true?
does the aqara have better durability or precision? …seems like the xiaomi is a no brained.
A Tale of Two Sensors
The yellow line is an Aqara Zigbee sensor with temperature, humidity and pressure. It doesn't update the sensor readings very often. It costs $15 and requires a USB Zigbee adapter for $20-30. Many Zigbee devices also act as repeaters to extend range. [1]
The green line is a Xiaomi Bluetooth sensor with temperature and humidity. It costs $6 and requires a $6 ESP32 to bridge bluetooth to HomeAssistant with the ESPHome firmware. You also get an LCD display, battery level, battery voltage and signal strength. [2]
So for $3 less you gain high time-resolution sensor readings and an LCD screen showing temperature and humidity. You lose pressure, but pressure will be the same everywhere so it's not necessary to have it in every sensor.
The graph comes from Grafana integrated with HomeAssistant. These particular sensors are monitoring an incubator.
#homeassistant #grownostr
[1] https://cloudfree.shop/product/aqara-temperature-and-humidity-sensor/
[2] https://cloudfree.shop/product/xiaomi-mijia-bluetooth-temperature-and-humidity-sensor/
Discussion
brainer*
In theory Zigbee has more range, but in my limited experience it's only slightly more than Bluetooth.
I'm not sure about durability. Both seem to be intended for indoor use only.
They both use a CR2032 and I haven't had them long enough to see a battery die. I'd get some warning with the Bluetooth sensor because it reports battery level.
For precision, the Zigbee has a wider range but less precision: -20 to 50 C at +/- 0.3 C vs the Bluetooth 0 to 60 C at +/- 0.1 C. For humidity the Zigbee is +/- 3% while the Bluetooth is +/- 1%.
There are pros and cons to both, and the best choice depends on your own circumstances and needs. I think the Bluetooth sensor is the better choice when you need higher resolution data or the LCD display. On the other hand it can't measure below freezing.
yea, all depends on the application! i can be a sucker for data, so i’m drawn to the bluetooth one for the higher resolution / update rate.