Last month ago, I ordered some cheap BLE temperature/humidity sensors from eBay. They finally arrived last weekend, and I used an ESP32 with #ESPHome to get the sensor readings from them.
Initially I just wanted a sensor for the utility closet as that's where my #homelab lives, but the sensors were quite cheap so I bought a pack of 5 and put one in each room. The living room has not been comfortable this week. 😅