If you are leaning toward making your own with Bluetooth, you can take a look my thread here.
I just make what I called Bluetooth proxy functional up to the point I can talk to a couple devices.
Here is a video what It can do.
[Zigbee Environment Sensor with Bluetooth]
The proxy can handle BLE Advertisement and BLE GATT write functionality. My goal is to build the proxy at GATT level so that it can support wider devices. Currently, It work with the following sensors.
[flower] [temp]
The BT proxy as seen on the demo will be my gateway to sensors like Xiaomi.
It will…
There is a cheap Hygrometer on sale at Amazon today. It is $17 with coupon U3HDBCG5
https://www.amazon.com/dp/B0872X4H4J?tag=slickdeals09-20&ascsubtag=72825a4aee1811eab34b7a1b1e43ba390INT
It is not a presence sensor. But, It will act like one. You can put one of them in a car. When your car approach your house, it will be detected like a Bluetooth beacon.
