This is about how to have a ESP32 Dev Kit communicate with an MQTT Server.
The chosen approach includes: 1 x ESP32 Dev Kit (WROOM32) 1 x bread board 1 x Resistor for pull-down of PIN "D23" to be able to flash the microcontroller (1k) 3 x resistor for current limiting for the used LEDs (100R) 3 x LED
(see pinning: https://raw.githubusercontent.com/playelek/pinout-doit-32devkitv1/master/pinoutDOIT32devkitv1.png) D23 -- 1k -- GND D21 -- 100R -- red LED -- GND D19 -- 100R -- yellow LED -- GND D18 -- 100R -- green LED -- GND
Visual Studio Platformio IDE ("open source ecosystem for IoT development") for VSCode https://platformio.org/platformio-ide library: PubSubClient inside VSCode (Visual Studio) free MQTT Server / Broker: https://dioty.co (see an overview here: http://www.steves-internet-guide.com/iot-mqtt-dashboards/) Mobile App from dioty but other MQTT Dashboards work as well. To be tried out: node-red
Setting up MQTT using with Visual Studio (Arduino) https://www.youtube.com/watch?v=5tG3JXFYrUo Quick Start Guide: http://docs.platformio.org/en/latest/platforms/espressif32.html?utm_source=github&utm_medium=arduino-esp32