Simple example of secure mqtt connection with root CA/fingerprint for ESP32/ESP8266 boards (send data to mqtt.flespi.io via MQTT over TLS)
Install library:
Sketch -> Include Library -> Manage Libraries... -> Type PubSub in Search field -> PubSubClient by Nick O'Leary -> Install.
Official Arduino IDE info on how to install additional cores
Arduino IDE: Tools -> Board -> Your board type (ESP32 Dev Module in my case ESP32 DevkitC v4)
register on flespi platform, create a Token in a tokens Tab and paste token in credentials.h file definitions:
#define FLESPI_TOKEN "FlespiToken REPLACE_WITH_YOUR_FLESPI_TOKEN"
compile the project and flash the board
To test it works you can use flespi online MQTT client:
Paste yout token and subscribe to topic "hello/world"
If you get an error when uploading a sketch:
A fatal error occurred: Could not open /dev/ttyACM0, the port doesn't exist
Failed uploading: uploading error: exit status 2
Try running the commands:
sudo adduser $USER $(stat --format="%G" /dev/ttyACM0 )
sudo chmod a+rw /dev/ttyACM0
MIT license.