Xiaomi’s ultra-affordable Bluetooth temperature sensor can be easily flashed with the ATC custom firmware using your phone’s web browser to allow for customization.
Once flashed, just follow the ESPHome instructions to use an ESP32 board and bridge this data into your Home Assistant instance.
Uses one CR2032 coin cell battery (included)
Stephen O (verified owner) –
While it isn’t required, I actually flashed alternative firmware on these little guys found here:
I used ESPHome with an ESP32 in order to have 3 of these devices report back into home assistant.
They are smaller than I expected. I have about 8 days worth of data now. Extrapolating that out at current burn, the battery will last somewhere between 45-50 days
I also use the newer firmware based on ATC. They have been running for nearly a year, and have had to replace only 2 batteries out of 15, so far.
T (verified owner) –
I bought 3 of these and flashed them to use with ESPhome. Its been about 3 months and they still work perfectly. My only complaint is that I wish they displayed in F, but that’s not a CloudFree issue. Keep up the good work!
Kenny Stier –
Connect to them using the TelinkMiFlasher page, there is an option to change the unit to Fahrenheit.