Rebuilding the DIY alarm system

I’ve decided to completely rebuild my DIY alarm system. Mean Well UPS supply instead of C-TEK charger Bigger battery in dedicated cabinet Arduino Mega as core, Raspberry Pi only as MQTT relay End-of-line resistors The biggest change is undoubtedly moving the alarm state machine and all logic from the Raspberry Pi to an Arduino Mega. There are three main reasons for this move: It’s fun and I’d like to work more with the Arduino The Arduino Mega has 16 analog inputs, making it possible to use end-of-line resistors An alarm system needs to be stable — not crash, hang or get a corrupted SD card I’ve been thinking about end-of-line resistors since I first got started, but the Raspberry Pi doesn’t have any analog inputs. Initially I thought of using the Arduino Mega as an I/O interface device, but as I got started I figured why not let it do more. So #RPiSecuritySystem is now #DIYAlarmSystem.