Bed presence detection could be very useful in home automation to control the lights and appliances you don’t need at night, but want to be ready in the morning. And today we will build a bed presence sensor out of a very universal device for DIY IoT. It is an Aqara ZigBee window and door sensor. Why it is so universal? Let’s take a closer look at its internals.

Home Assistant 0.115 got the ability to use variables in automation and scripts. You can declare variables even using templates and use them across the script or automation. Here is an example from the release notes:

automation:
  trigger:
    platform: sun
    event: sunset
    offset: -00:30
  variables:
    notification_service: notify.paulus_iphone
  action:
    - service: "{{ notification_service }}"
      data:
        message: Beautiful sunset!

Previously my presence detection in Home Assistant works through Asus router and asuswrt component. And it was bad. Very bad. Recently I switched to Google WiFi and realized that the only way to implement presence detection with this router is IFTTT (Update: No). I thought it would be the slowest presence detection in the world but I was wrong.

So I have several Xiaomi Aqara buttons. Today I want to explain how to use this button as a smart doorbell that will play sound to your Google Home device through Home Assistant.

So there was a simple air humidifier… Actually, this post is a good example of how to make your regular boring home appliance a little smarter. The main part of my humidifier will be the Wemos (or Lolin) D1 mini board based on the ESP8266 WiFi chip.