good morning,
I would like to implement some wireless door sensor.
Could you advise me what kind of sensor and what do I need to access it?
Thank you so much, Alberto
you can get whatever you like, but it will all depend on what communications protocol you have available…
I would suggest getting a “Z-Wave +” based sensor as this will give you the longest range and lowest interference with other household wireless devices. You will obviously need a z-wave module for whatever you are running home assistant on…
So, something like this to plug into home assistant: https://aeotec.com/z-wave-usb-stick
and a sensor like this: https://aeotec.com/smallest-door-window-sensor
but you dont have to get the same make of sensor, any z-wave device will connect as long are both rated for use in your country… (check the frequency)
The Xiaomi/aqara devices are used by many here, are well supported, work well and are cheap.
You can use with the native aqara component (with the xiaomi hub) or with other zibgee coordinators (zigbee2mqtt, conbee etc).
yes agreed, I have a mix of these Xiaomi (zigbee) as well as other z-wave sensors, however if I were starting again from scratch, I would focus all my sensors on z-wave due to the characteristics of the frequency… Either technology works better if you have lots of the same sensors in mesh… my last count is around 60 zigbee sensors (they tend to be cheaper as zigbee is an unlicensed technology) and around 30 z-wave sensors (They are more expensive and based on a licenced technology, but use uncluttered radio frequency)
I think also one of the reasons that zigbee is cheaper is because of the lack of regional frequency allocation. It means that zigbee works wherever you buy your kit from (import from the far east, buy locally in EU, buy on holiday in the US etc). Hence bigger unfragmented market.
Regarding frequency for zibgee its definitely important to ensure your 2.4ghz wifi (b,g,n) and zigbee channels are not interfering.
From here.
Honestly though I never tried zwave so I cannot comment on pros/cons.
Its one more radio protocol I decided not to use. Wifi (esphome/tasmota) and zigbee (zigbee2mqtt), plus receiving of 433MHz via rtl_433 is enough for me.
z-wave is lower frequency therefore better coverage (lower frequency travels further) and less interference…
I get most my z-wave kit off aliexpress… just make sure it is EU version… (868.42 MHz)
Ok, the winner is zwave 
Thanks boys