#include <WiFi.h>
#include <PubSubClient.h>
#include <DHTesp.h>
const int DHT_PIN = 17;
DHTesp dht;
const char *ssid = "Wokwi-GUEST";
const char *password = "";
const char *mqtt_server = "test.mosquitto.org";
WiFiClient espClient;
PubSubClient client(espClient);
unsigned long lastMsg = 0;
String tempValue = "0";
String humValue = "0";
void setup_wifi()
{
delay(10);
Serial.println();
Serial.print("Connecting to ");
Serial.println(ssid);
WiFi.mode(WIFI_STA);
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED)
{
delay(500);
Serial.print(".");
}
randomSeed(micros());
Serial.println("");
Serial.println("WiFi connected");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
}
void callback(char *topic, byte *payload, unsigned int length)
{
// Handle incoming MQTT messages if needed
}
void reconnect()
{
while (!client.connected())
{
Serial.print("Attempting MQTT connection...");
String clientId = "ESP32Client-";
clientId += String(random(0xffff), HEX);
if (client.connect(clientId.c_str()))
{
Serial.println("Connected");
client.publish("/ThinkIOT/Publish", "Welcome");
client.subscribe("/ThinkIOT/Subscribe");
}
else
{
Serial.print("failed, rc=");
Serial.print(client.state());
Serial.println(" try again in 5 seconds");
delay(5000);
}
}
}
void setup()
{
pinMode(2, OUTPUT);
Serial.begin(115200);
setup_wifi();
client.setServer(mqtt_server, 1883);
client.setCallback(callback);
dht.setup(DHT_PIN, DHTesp::DHT22);
}
void loop()
{
if (!client.connected())
{
reconnect();
}
client.loop();
unsigned long now = millis();
if (now - lastMsg > 2000)
{
lastMsg = now;
TempAndHumidity data = dht.getTempAndHumidity();
tempValue = data.temperature;
humValue = data.humidity;
client.publish("/ThinkIOT/tempValue", tempValue.c_str());
client.publish("/ThinkIOT/humValue", humValue.c_str());
Serial.print("tempValue: ");
Serial.println(tempValue);
Serial.print("humValue: ");
Serial.println(humValue);
}
}