The Arduino MySensors library makes it possible to create connected objects (IoT) and to make them communicate by radio waves. The library is responsible for creating a network of sensors and actuators that communicate with each other. MySensors supports 2.4GHz (nRF24L01) and 915mHz (RFM69) radio frequencies. The main home automation servers natively support the protocol. It is very easy to manufacture your own probes (temperature, humidity, air pollution, water leak detection, barometer …) and integrate them into Domoticz, Jeedom, OpenHAB, Home Assistant, just to name a few. the main ones. It is also very easy to use sensors and actuators from Node-RED. To operate and communicate with another software, gateway or gateway (network or serial) and necessary. Since version 2, it is possible to build a WiFi Gateway using an ESP8266 module.