Wanna know when the door is opened for ages. I built one using an ultrasonic sensor a year before, it worked, with a rate about 50:50. Sometime it does missed the event. There were couples reason, I just didn’t spent addition time to fix those issues (like wi-fi connectivity issue) and have it aborted.
I finally got a EVE door and window sensor from Apple store. It works. It is easy to install. EVE line of product uses bluetooth and it is usually super easy to have the things running out of the box.
One cons though. The sensor use a 1/2 AA battery. I have no idea where I can buy one here. Never ever heard about 1/2 AA (or ER14250) before.
With the help of homebridge on raspberry pi, homekit will capture an image from my Panasonic IP cam and then email to me whenever the door is opened. This allow me to understand that whether there is a guest or actually a thief visiting.
Couldn’t really recommend this sensor right now as I had pretty bad experience with two of my EVE motion sensor. Need at least one month of usage to identify whether the device is actually stable and ready for production use, or not.
To be update regarding the stability of the device later.