#include <WiFi.h>
#include <PubSubClient.h>
#include <DHT.h>
const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqtt_server = "broker.hivemq.com"; // or your own broker
const int mqtt_port = 1883;
const char* temp_topic = "esp32/dht22/temperature";
const char* hum_topic  = "esp32/dht22/humidity";
WiFiClient espClient;
PubSubClient client(espClient);
#define DHTPIN 4       // GPIO where DHT11 is connected
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);
void setup_wifi() {
  delay(10);
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.print(".");
  }
  Serial.println("\nWiFi connected!");
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());
}
void reconnect() {
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    if (client.connect("ESP32Client")) {
      Serial.println("connected");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(". Trying again in 5 seconds...");
      delay(5000);
    }
  }
}
void setup() {
  Serial.begin(115200);
  dht.begin();
  setup_wifi();
  client.setServer(mqtt_server, mqtt_port);
}
void loop() {
  if (!client.connected()) {
    reconnect();
  }
  client.loop();
  float temp = dht.readTemperature();
  float hum = dht.readHumidity();
  String temp_json = "{\"temperature\": " + String(temp) + "}";
  String hum_json  = "{\"humidity\": " + String(hum) + "}";
  Serial.println("Sending to MQTT:");
  Serial.println("Temp -> " + temp_json);
  Serial.println("Hum  -> " + hum_json);
  client.publish(temp_topic, temp_json.c_str());
  client.publish(hum_topic, hum_json.c_str());
  delay(5000); // Wait for 5 seconds before next reading
}