This small script is a cheap and easy way to start with IoT projects. By using the great rtl_433 software and a cheap RTL-SDR receiver it will listen to all kinds of devices transmitting at the 433,92 Mhz frequency.

Quite likely it will receive information from weather stations in your area, if you don't own one, your neighbours might! It will also receive signals from remote controls that are popular to use to control the lights.

The gateway will receive information from the SDR receiver and publish them in JSON format to the topic sensors/rtl_433. (Without the slash!)

Subtopics are created from this JSON line allowing to easily subscribe to specific sensors.

Requires the rtl_433 utility as its data source.