[[Home Assistant]] > [!Images]+ > ![XIAOMI Mijia LYWSD03MMC Bluetooth 4.2 Thermometer Hygrometer Second Generation | eBay](https://tvc-b2c-public.oss-cn-shenzhen.aliyuncs.com/uploads/details/680200028A-2.jpg) LYWSD03MMC https://pvvx.github.io/ATC_MiThermometer/TelinkMiFlasher.html The **LYWSD03MMC** is a Bluetooth temperature and humidity sensor manufactured by Xiaomi. According to the search results: > > - It can be converted from Bluetooth to Zigbee by flashing a custom firmware onto the device.[1][2] This allows it to integrate into smart home systems like Home Assistant and ESPHome that support Zigbee devices. > > - It has an LCD screen to display temperature, humidity and battery level.[3] > > - Custom firmware has been developed to run on the LYWSD03MMC that converts it to a Zigbee device rather than Bluetooth, allowing it to connect to platforms like Zigbee2MQTT, ESPHome and Home Assistant.[4][5] > > - Guides exist online on how to flash this custom Zigbee firmware onto the LYWSD03MMC using a USB to serial converter to convert it from Bluetooth to Zigbee.[6][7] > > - It is an inexpensive $4 temperature and humidity sensor that can be made compatible with various smart home platforms by flashing open source custom firmware onto it.[8] > > > [1] [Converting Xiaomi LYWSD03MMC Temperature sensor ... - Reddit](https://www.reddit.com/r/homeassistant/comments/17jsq7m/converting_xiaomi_lywsd03mmc_temperature_sensor/) > [2] [atc1441/ATC_MiThermometer](https://github.com/atc1441/ATC_MiThermometer) > [3] [Xiaomi Mijia BLE Sensors - ESPHome](https://esphome.io/components/sensor/xiaomi_ble.html) > [4] [devbis/z03mmc](https://github.com/devbis/z03mmc) > [5] [Xiaomi Temperature & Humidity Sensor Home Assistant Integration ...](https://community.home-assistant.io/t/xiaomi-temperature-humidity-sensor-home-assistant-integration-pvvx-custom-firmware-may-2023/572569) > [6] [Convert Xiaomi LYWSD03MMC BLE Sensor to Zigbee](https://smarthomescene.com/guides/convert-xiaomi-lywsd03mmc-from-bluetooth-to-zigbee/) > [7] [Home Asssistant Xiaomi Mijia LYWSD03MMC Temperature and ...](https://community.home-assistant.io/t/home-asssistant-xiaomi-mijia-lywsd03mmc-temperature-and-humidity-sensor-tutorial-september-2022/456403) > [8] [4$ Xiaomi thermometer custom firmware LYWSD03MMC ... - YouTube](https://www.youtube.com/watch?v=NXKzFG61lNs)