Objective

To link Xiaomi Mi Temperature and Humidity Monitor to Home Assistant

Tested Hardware

Xiaomi Mi Temperature and Humidity Monitor (Hardware Version: LYWSD03MMC)

Resources

Telink Flasher v4.4 (pvvx.github.io)

Issues · pvvx/ATC_MiThermometer · GitHub

Flashing Firmware

Connecting to Sensor

• Use your laptop (with BT device) and go to Telink flasher (link in resource above)
• In the name prefix, use “LYWS” and click on Connect
• After connected, wait for the log to say connected and Temp+Humidity value appear
• Click on Do Activation
• You should be able to receive Mi Token and Mi Activation code
• Click on Custom Firmware ver x.xx and click on Start Flashing to start flashing
• Avoid using BT mouse and keyboard for the time being
• Wait until 100%, try to stay on the web page just in case
• Device will get disconnected automatically

Connecting to Flashed Sensor

• Clear log to avoid confusion
• In the name prefix, use “ATC” and click on Connect
• The device should change name to ATC_###### where ###### is the last 6 digit of its MAC Address
• Set the time to update the device time
• Change Advertising type to Mijia
• Change RF TX Power to VANT+0.90dbm
• Click on Send Config
• Click on Disconnect button

Connect to HomeAssistant

Add device

• Go to Settings > Device
• Add Integration, choose Xiaomi BLE
• Your device should be showing
• Click on Submit