Securing ESP32 Home Automation System with MQTT over SSL/TLS for Voice-Controlled Appliances

#include <WiFi.h>
#include <PubSubClient.h>
#include "DHT.h"

#define DHTPIN 5
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);

const char* ssid = "your_SSID";
const char* password = "your_PASSWORD";
const char* mqtt_server = "broker.hivemq.com";

WiFiClient espClient;
PubSubClient client(espClient);

void setup() {
  Serial.begin(115200);
  WiFi.begin(ssid, password);
  
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.println("Connecting to WiFi...");
  }
  Serial.println("Connected to WiFi");
  
  client.setServer(mqtt_server, 1883);
  
  dht.begin();
}

void loop() {
  if (!client.connected()) {
    reconnect();
  }
  client.loop();
  
  float temp = dht.readTemperature();
  float hum = dht.readHumidity();
  
  if (isnan(temp) || isnan(hum)) {
    Serial.println("Error reading from DHT22 sensor");
    return;
  }
  
  String tempString = String(temp);
  String humString = String(hum);
  
  client.publish("home/temperature", tempString.c_str());
  client.publish("home/humidity", humString.c_str());
  delay(2000);
}

void reconnect() {
  while (!client.connected()) {
    Serial.println("Connecting to MQTT...");
    if (client.connect("ESP32Client")) {
      Serial.println("Connected to MQTT");
    } else {
      Serial.print("Failed, rc=");
      Serial.print(client.state());
      delay(5000);
    }
  }
}