Primeiro que tudo há que extrair o TOKEN
Para extrair o token, basta seguir estas instruções (WIndows).
- Configure o aspirador com a APP Mi-Home.
 - Fazer o download e extraia o MiToolKit.zip.
 - Ativar o modo de desenvolvedor e depuração USB no telefone Android e conecte-o ao computador.
 - Alterar o idioma do MiToolKit para inglês, se precisar.
 - Clique em “Extrair token”
 - No telefone, você deve confirmar o backup. NÃO insira nenhuma senha e pressione o botão para fazer o backup.
 - Depois de confirmar o backup, a extração do token começará, ele deverá aparecer no MiToolKit.
 
Após isto, criei um xiaomi_vacuum.yaml dentro da pasta packages e inseri o seguinte codigo:
homeassistant:
vacuum:
  - platform: xiaomi_miio
    host: 192.168.1.73
    token: 4ffeerer632rterergr4534jhhb34hvjtg3v4v
################################################
#             SENSORES ASPIRADOR               #
################################################
sensor:
  - platform: template
    sensors:
      xiaomi_status:
          value_template: >
            {%- if states.vacuum.xiaomi_vacuum_cleaner.attributes.status == "Charging" %}
              A carregar
            {% elif states.vacuum.xiaomi_vacuum_cleaner.attributes.status == "Cleaning" %}
              A limpar
            {% elif states.vacuum.xiaomi_vacuum_cleaner.attributes.status == "Returning home" %}
              A voltar à base
            {% elif states.vacuum.xiaomi_vacuum_cleaner.attributes.status == "Idle" %}
              Parado
            {% else %}
              {{ states.vacuum.xiaomi_vacuum_cleaner.attributes.status }}
            {%- endif %}
          friendly_name: Estado
      xiaomi_battery_level:
          value_template: >
            {{ states.vacuum.xiaomi_vacuum_cleaner.attributes.battery_level }}
          friendly_name: Bateria
          unit_of_measurement: '%'
      xiaomi_main_brush_left:
          value_template: >
            {{ states.vacuum.xiaomi_vacuum_cleaner.attributes.main_brush_left }}
          friendly_name: Escova principal
          unit_of_measurement: 'horas'
      xiaomi_side_brush_left:
          value_template: >
            {{ states.vacuum.xiaomi_vacuum_cleaner.attributes.side_brush_left }}
          friendly_name: Escova lateral
          unit_of_measurement: 'horas'
      xiaomi_filter_left:
          value_template: >
            {{ states.vacuum.xiaomi_vacuum_cleaner.attributes.filter_left }}
          friendly_name: Filtro
          unit_of_measurement: 'horas'
Façam reboot e já vão ter as entidades no menu “estados”… a ser assim é so adicionarem / organizarem o vosso groups.yaml
NOTA: o meu configuration.yaml está da seguinte forma:
homeassistant:
  # Name of the location where Home Assistant is running
  name: Home Assistant
  # Location required to calculate the time the sun rises and sets
  latitude: !secret key_lat
  longitude: !secret key_lon
  # Impacts weather/sunrise data (altitude above sea level in meters)
  elevation: !secret key_ele
  # metric for Metric, imperial for Imperial
  unit_system: metric
  # Pick yours from here: http://en.wikipedia.org/wiki/List_of_tz_database_time_zones
  time_zone: Europe/Lisbon
  # Customization file
  customize: !include customize.yaml
  packages: !include_dir_named packages
Espero ter ajudado.