#include <WiFi.h>
#include <PubSubClient.h>
#include <DHT.h>
#include <ArduinoJson.h>
#define DHTPIN 22
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);
const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqttServer = "broker.emqx.io";
const int mqttPort = 1883;
WiFiClient wifiClient;
PubSubClient mqttClient(wifiClient);
void setupMQTT() {
mqttClient.setServer(mqttServer, mqttPort);
}
void reconnect() {
while (!mqttClient.connected()) {
Serial.println("Connecting to MQTT Broker...");
String clientId = "ESP32Client-";
clientId += String(random(0xffff), HEX);
if (mqttClient.connect(clientId.c_str())) {
Serial.println("Connected to MQTT Broker");
} else {
Serial.print("Failed, rc=");
Serial.print(mqttClient.state());
Serial.println(" Retrying in 5 seconds...");
delay(5000);
}
}
}
void connectToInternet(){
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("");
Serial.println("Connected to Wi-Fi");
}
void setup() {
Serial.begin(115200);
dht.begin();
connectToInternet();
setupMQTT();
}
void loop() {
if (!mqttClient.connected()){
reconnect();
} else {
float temperature = dht.readTemperature();
float humidity = dht.readHumidity();
StaticJsonDocument<200> jsonDoc;
jsonDoc["temperature"] = temperature;
jsonDoc["humidity"] = humidity;
char jsonString[200];
serializeJson(jsonDoc, jsonString);
Serial.println("JSON Data:");
Serial.println(jsonString);
mqttClient.publish("100/DHT", jsonString);
delay(2000);
}
}