Xiaomi Thermometer LYWSD03MMC

Flash firmware

Using this project you can flash your Xiaomi Thermometer LYWSD03MMC Visit the Flasher Page.

Use it with ESPHome

You are gonna need an ESP32 as a bluetooth transceiver like the Wemos LoLin32 ESP32

Flash ESPHome to ESP32 following the guide on EPSHome’s website.

Basic config for the transceiver

esphome:
  name: bluetooth_transceiver
  platform: ESP32
  board: esp-wrover-kit

wifi:
  ssid: "WiFi Name"
  password: "WiFi Password"
  domain: ".localdomain"

  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
    ssid: "Bluetooth Transceiver"
    password: "fallbackPassword"

captive_portal:

# Enable logging
logger:

# Enable Home Assistant API
api:

ota:

esp32_ble_tracker:

Configuration (Example)

• You can find thermometer’s MAC address while flashing the firmware or let ESPHome discover it after the first flash.
• You can put any bind key you want (Assuming you used Mi Like as Advertising Type.

esphome:
  name: bluetooth_transceiver
  platform: ESP32
  board: esp-wrover-kit

wifi:
  ssid: "WiFi Name"
  password: "WiFi Password"
  domain: .localdomain

  # Enable fallback hot spot (captive portal) in case wifi connection fails
  ap:
    ssid: "Bluetooth Transceiver"
    password: "fallbackPassword"

captive_portal:

# Enable logging
logger:

# Enable Home Assistant API
api:

ota:

esp32_ble_tracker:

sensor:
  - platform: xiaomi_lywsd03mmc
    mac_address: "A4:C1:38:20:FC:30"
    bindkey: "eef418daf699a0c188f3bfd17e4565d9"
    temperature:
      name: "Server Rack Temperature"
    humidity:
      name: "Server Rack Humidity"
    battery_level:
      name: "Server Rack Battery Level"

  - platform: xiaomi_lywsd03mmc
    mac_address: "A4:C1:38:BE:4F:7A"
    bindkey: "eef418daf699a0c188f3bfd17e4565d9"
    temperature:
      name: "Lab Temperature"
    humidity:
      name: "Lab Humidity"
    battery_level:
      name: "Lab Battery Level"

Repeat - platform: xiaomi_lywsd03mmc code block for every sensor you want to add.

More in-depth info about configuration you can find here