Retrofit Fireangel smoke alarm with Wemos D1 mini
Hardware:
Wemos D1 mini,
FireAngel SB1-TP-R Smoke Alarm,
390K resistor,
2 x 680K resistors
Description: This takes a 'dumb' optical smoke alarm and adds MQTT capability, my usage is for my 3D printer connected with Octoprint. If the detector notices smoke, it sends a MQTT message to the broker. Via node red this sends a MQTT message to a Sonoff S20 smart plug, killing the power. Also via node red it notifies me via my phone (I use Blynk app, you can use whatever you want).