Posted in Microcontrollers Tagged google assistant, home automation, MQ2, NodeMCU, smoke detector, smoke sensor A Big 3D Printer Built Using The Power Of Procrastination November 26, 2016 by ...

A way to apply the output of certain sensors to a TTL/CMOS-level iput on a microcontroller. Sensor must have an NPN output stage that can support a pullup to its power rail.