DIY Smart Doorbell for just $2, no soldering required » Frenck.dev
— This article is going to show you how to convert your (existing) wired doorbell (also works for battery-powered chimes) into a smart, WiFi-enabled, doorbell. The essential components needed sets you back about $2, yes, that is correct, just two bucks. No soldering is required and you don’t have to be an electronics expert.