Here is a jolly cute, palm-sized, Bluetooth-enabled sensor to monitor your room's temperature and humidity. Only 43mm x 43mm, we dig its small form factor and minimal design.

The shell is made of durable ABS material. Up front you get a 1.5" (28x28mm) LCD display. These sensors are sold to work with the Mijia "Mi Home" App (iOS and Android) and are a low cost way to add environmental sensing up to about 10 meters away.

And while it's totally fine to use it with the Mi app, we like this more for its use cases in general home automation and sensing projects!

The sensor has two modes. One is advertising modes, where it sends out sensor data every few minutes. The advertisements are encrypted so not easy to read. You can also connect to it as a BLE device and read from the sensor characteristic, which thankfully is not encrypted. You can use this with our library library for the LYWSD03MMC that works with CircuitPython. Or you can also hack it to add your own custom firmware to remove the encryption on advertisementsYou can also use these with ESPHome / Home Assistant by extracting the binding key.

Comes with a back adhesive sticker, so you can mount the sensor anywhere you please.

Please note, to make air shipping easier, we no longer include a CR2032 battery. If you need one, please purchase separately.

Technical Details:

Temperature range: 0ºC - 60ºC
Humidity range: 0% - 99% RH
Product Dimensions: 43.0mm x 43.0mm x 12.5mm / 1.7" x 1.7" x 0.5"

Revision History:

As of November 2022 - this version no longer comes with a CR2032 coin cell battery. We do stock CR2032 coin cell batteries in case you wanted to grab a few.

Package Includes: