[Madmanmoe64] has really done a fantastic job with this burglar alarm built into a zippo. He crammed a picaxe microcontroller, some IR LEDs, an IR sensor, a battery and various switches in there ...

[Jeff Sandberg] demonstrates that ably with his project to use ancient 1990s burglar alarm sensors in his modern smarthome setup. The sensors in question are from an old GM Interlogix security system.

Sound Detection functionality, which requires a Nest Aware subscription, is no longer offered on Google Home Max.