Useful Link to learn websocket & MQTT https://www.espruino.com/MQTT -- -- -- mqtt functions https://www.ably.io/documentation/mqtt ----- Publ...
What is Quality of Service? The Quality of Service (QoS) level is an agreement between the sender of a message and the receiver of a message...
WebSocket can connect with IoT sensor over a server. TCP protocol can communicate with sensor with mqtt.js library.