References

1. Eclipse Foundation, "MQTT Essentials: A Lightweight IoT Protocol", Available at: https://mqtt.org
2. ESP32 Official Documentation, "MQTT Client Usage", Available at: https://docs.espressif.com
3. Adafruit Learning System, "DHT Sensor Guide", Available at: https://learn.adafruit.com
4. Rui Santos, "ESP32 MQTT Publish and Subscribe Tutorials", Random Nerd Tutorials, 2020.
5. Arduino Official Documentation, "PubSubClient MQTT Library Reference", Available at: https://www.arduino.cc/reference/en