MQTT Sensor Hub
One of the main projects we published in a recent issue was the Monster LED Clock, featuring huge seven-segment displays. These were not just able to show the time of day: it was also possible to use them to display sensor values received over a wireless network using MQTT. In this article we look at some alternative firmware that allows the direct connection of sensors to the ESP32 in the clock. The data are sent using MQTT to a central broker, which can be implemented using a Raspberry Pi running Mosquitto and Node-RED. The firmware for this MQTT sensor hub was built with the help of software modules recycled from various projects, which saved a lot of development time.