A while ago I bought the Aquara door/window sensors from Xiaomi with a price tag of €40 for 4 sensors. The sensors are not only cheap but have an instantaneous response within homeassistant.
The Aquara itself
Most sensors are big and bulky, the aquara’s are small and beautiful
Side view 
Top view
With a size of only: 4.1 x 2.2 x 1.1 cm the aquara can fit almost anywhere. And a single CR1632 helps to keep the package as small as possible. in addition to the small body there is M3 sticky tape on the back, therefore montage is easy.
The used communications protocol is Zigbee, therefore it’s part of the mesh network.
Installing
In order to install the sensors properly, it’s important to meet the prerequisite; A running zigbee setup.
I have a tutorial which can be found here.
To install you’ll need to pull the insulation tab so the sensor will go in pairing mode. When in pairing mode go into home assistant and add to deconz.
When adding the sensor to deconz and homeassistant is completed; physically install the sensor to a door or window.
To add the sensor to a door or window; pull the tab at the back of the sensor and place it against the spot you like and you’re done.
conclusion
Adding a aquara sensor to homeassistant is easy to do.
next thing to do is creating automations.
Thanks for reading!
