At the Feb 2017 NashMicro meetup, I presented on Real Time Operating System fundamentals while simultaneously demoing a system of ESP32 based devices running MQTT and lighting up some LED Light Strips with fun patterns.
Find the presentation here:
https://covemountainsoftware.com/data/
or directly:
Real Time Operating Systems at NashMicro Feb2017
The source code for the demo may be found here:
https://github.com/mattheweshleman/FreeRTOSEsp32AccelLedStripMqttDemo