What contact and motion sensors are compatible with the kit?
Anyway, I’ll be getting myself a high-capacity UPS for my server and networking equipment so that should not be that much of a problem, but I do want to know what other Home Assistant users are using for their setups when it comes to home security.
Either board would be suitable for a DIY security solution. ESP8266 is great for wireless connectivity but has limited IO capability (especially on the analogue side), so you might end up pairing with an Arduino Pro-Mini or attiny anyway. You should also check out Arduino with MySensors, which is a lower power option suitable for battery operation. Both boards should work with motion detectors, since internally most of those PIR sensors use 3v3 logic.
I would be hesitant to use a DIY system for smoke alarms, since you and your family’s life might depend on the basic smoke detection/alarm functionality. Maybe take a look at a Z-Wave option.
Well you could produce the same functionality with the Arduino/ESP8266 by attaching a PIR, a light sensor and a battery, and having a sensor which controls the lights whilst you are in and switches to an alarm system when you are away. It is working nicely for me with the Hue. I did have an ESP8266 doing this previously (sans light sensor) but switched to the Hue as a very neat package. cheers