; Date: April 17, 2017
MQTT is a lightweight communications protocol meant for Internet of Things devices. It acts like a giant merry-go-round sending messages through a hierarchical structure of ports. It offers three levels of Quality of Service, from level 0 where messages can be lost, to level 2 where messages are held and resent if necessary. MQTT is easy to install on a Raspberry Pi or other Linux Single Board Computing device. MQTT itself is powerful, and the NODE RED platform (which is bundled in the Raspberry Pi) can make great use of MQTT and other facilities.
Capaldi's Doctor is one to HATE, or is he? Control a power outlet with an ESP8266 running MQTT via a relay