I didn’t want to start home assistant as root, so I wrote a small mqtt gateway for the mi scale: https://gist.github.com/syssi/4108a54877406dc231d95514e538bde9
This is my home assistant configuration:
sensor:
- platform: mqtt
name: "miscale"
state_topic: "miscale/weight/kg"
value_template: "{{ value }}"
unit_of_measurement: "kg"
You have to change the MISCALE_MAC, MQTT_USERNAME, MQTT_PASSWORD and the MQTT_HOST. Have fun! For a successful passive bluetooth scan root privileges are required.