Wokwi ESP32 DHT22 + MqttGo.io Broker / Client

Wokwi ESP32 DHT22 + MqttGo.io Broker / Client 

免費MQTT Broker https://broker.mqttgo.io/

1. MQTTGO.io (20220608新增)

   1. 尤老大公司出品

   2. mqttgo.io

   3. TCP Port：1883

   4. WebsocketPort：8000

      • 網址：mqttgo.io:8000/mqtt

   5. (2023/01/16更新)

      • tcp：mqttgo.io:1883

      • tcp/tls：mqttgo.io:8883

      • ws://mqttgo.io:8000/mqtt

      • wss://broker.mqttgo.io:8084/mqtt

圖片來源：https://swf.com.tw/images/books/IoT/MQTT/publisher_broker_subscriber.pngw

WOKWI ESP32程式 檔名:AS-ESP32-DHT22 MQTTgo.io

#include "DHT.h"

#include <Arduino.h>

#include <WiFi.h>

#include <PubSubClient.h>

char ssid[] = "Wokwi-GUEST";   // your network SSID (name)

char pass[] = "";   // your network password

const int LED_PIN = 13;

#define DHTPIN 4  

#define DHTTYPE DHT22   // DHT 22  (AM2302), AM2321

DHT dht(DHTPIN, DHTTYPE);

const size_t BUFFER_SIZE = 100;

char data[BUFFER_SIZE + 1];  // Extra one for NULL terminator.

long now = millis();

long last_time = 0;

// MQTT client

WiFiClient wifiClient;

PubSubClient mqttClient(wifiClient);

char *mqttServer = "broker.mqttgo.io";

int mqttPort = 1883;

String json1 = "";

String json2 = "";

//========================================================

void connectToWiFi() {

  Serial.print("Connectiog to ");

 

  WiFi.begin(ssid, pass);

  Serial.println(ssid);

  while (WiFi.status() != WL_CONNECTED) {

    Serial.print(".");

    delay(500);

  }

  Serial.print("Connected.");

}

//========================================================

void setupMQTT() {

  mqttClient.setServer(mqttServer, mqttPort);

  // set the callback function

  mqttClient.setCallback(callback);

  mqttClient.subscribe("alex9ufo/esp32/led");

}

//========================================================

void callback(char* topic, byte* payload, unsigned int length) {

  Serial.print("Callback - ");

  Serial.print("Message:");

  String message="";

  for (int i = 0; i < length; i++) {

    Serial.print((char)payload[i]);

    message += ((char)payload[i]);

  }

  Serial.println();

  message.trim();

  // Switch on the LED if an 1 was received as first character

  if (String(topic) == "alex9ufo/esp32/led") {

    Serial.print("Changing output to ");

    Serial.println(message);

    if(message == "on"){

      digitalWrite(LED_PIN, LOW);

    }

    else if(message == "off"){

      digitalWrite(LED_PIN, HIGH);

    }

  }

}

//========================================================

void reconnect() {

  Serial.println("Connecting to MQTT Broker...");

  while (!mqttClient.connected()) {

      Serial.println("Reconnecting to MQTT Broker..");

      String clientId = "ESP32Client-";

      clientId += String(random(0xffff), HEX);

     

      if (mqttClient.connect(clientId.c_str())) {

        Serial.println("Connected.");

        // subscribe to topic

        mqttClient.subscribe("alex9ufo/esp32/led");

      }

     

  }

}

//========================================================

void setup() {

  pinMode(LED_PIN, OUTPUT);     // Initialize the BUILTIN_LED pin as an output

  Serial.begin(115200);

  Serial.println(F("DHTxx test!"));

  connectToWiFi();

  dht.begin();

  setupMQTT();

}

//========================================================

void loop() {

  if (!mqttClient.connected())

    reconnect();

  mqttClient.loop();

  now = millis();

  if (now - last_time > 5000) {

   

    // Reading temperature or humidity takes about 250 milliseconds!

    // Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)

    //TempAndHumidity  data = dhtSensor.getTempAndHumidity();

    //float h = dht.readHumidity();

    //float t = dht.readTemperature();

    String temp = String(dht.readTemperature(), 2);

    json1= temp;

    mqttClient.publish("alex9ufo/esp32/temp", temp.c_str());

    Serial.print("Temperature: ");

    Serial.println(temp);

    String hum = String(dht.readHumidity() , 1);

    json2=hum;

    mqttClient.publish("alex9ufo/esp32/humi",  hum.c_str());

    Serial.print("Humidity: ");

    Serial.println(hum);

    last_time = now;

  }

 

}

//========================================================