How to connect my MQTT Broker in azure event Grid Namespace to my online ESP32 such as in wokwi ESP 32 ?

Question

Previously I had created an MQTT Broker in Azure Event Grid. I've followed the documentation at
https://learn.microsoft.com/en-us/azure/event-grid/mqtt-publish-and-subscribe-portal

there used and successfully published subscribe on MQTTx with 2 clients.

Is there any documentation on how I can connect my ESP32 either hardware or online such as using Wokwi ESP32 to use the DHT22 sensor to send temperature and humidity data.

Simply put I just want to use the MQTT Broker Azure event grid namespace to use it on my ESP32 as a broker with a DHT22 sensor

here's the code below :

but always get eror :

Failed, rc=-2 Retrying in 5 seconds...
Connecting to MQTT broker...

#include <WiFi.h>
#include <PubSubClient.h>
#include <ArduinoJson.h>
#include <WiFiClientSecure.h>

// Wi-Fi settings
const char* ssid = "Wokwi-GUEST";
const char* password = "";



// Azure Event Grid settings
const char* mqttBroker = "eventgrid1.southeastasia-1.ts.eventgrid.azure.net";
const int mqttPort = 8883;
const char* eventGridTopic = "Topics/topic1";
const char* username = "client1-authnID";
const char* deviceID = "client1-sessionID1";

// TLS/SSL client setup
WiFiClientSecure wifiClient;
PubSubClient mqttClient(wifiClient);

// Certificates
const char* caCert = "";

const char* clientCert = R"KEY(
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
)KEY";

const char* clientKey = R"KEY(
-----BEGIN EC PRIVATE KEY-----
MHcCAQEEIAb/hcl7cXX8gHH8gjlhXjcaj8pTonHP+MzqcS2rHY13oAoGCCqGSM49
AwEHoUQDQgAEmvEdmUuMBNnORlOjAKVjP7vRe/0KNQ0YUulT7K9s2tDk17jvQoTh
N7acbvBt/67MjOGz4/SOgwGTHmx1221/0w==
-----END EC PRIVATE KEY-----
)KEY";

void setup() {
  Serial.begin(115200);
  delay(2000);

  // Connect to Wi-Fi
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi...");
  }
  Serial.println("Connected to WiFi");

  // Load CA certificate, client certificate, and client key
  wifiClient.setCACert(caCert);
  wifiClient.setCertificate(clientCert);
  wifiClient.setPrivateKey(clientKey);

  // Set MQTT server and port
  mqttClient.setServer(mqttBroker, mqttPort);

  // Set MQTT callback function
  mqttClient.setCallback(callback);

  // Connect to MQTT broker
  connectToMqttBroker();
}

void loop() {
  if (!mqttClient.connected()) {
    // Reconnect to MQTT broker if the connection is lost
    connectToMqttBroker();
  }
  mqttClient.loop();

  // Publish message to Event Grid
  publishEvent();

  // Delay before publishing the next event
  delay(5000);
}

void connectToMqttBroker() {
  while (!mqttClient.connected()) {
    Serial.println("Connecting to MQTT broker...");

    if (mqttClient.connect(username, deviceID,"")) {
      Serial.println("Connected to MQTT broker");
    } else {
      Serial.print("Failed, rc=");
      Serial.print(mqttClient.state());
      Serial.println(" Retrying in 5 seconds...");
      delay(5000);
    }
  }
}

void callback(char* topic, byte* payload, unsigned int length) {
  // Handle incoming MQTT messages here if needed
}

void publishEvent() {
  // Create the event message
  DynamicJsonDocument eventMessage(256);
  eventMessage["id"] = "1";
  eventMessage["subject"] = "Example Event";
  eventMessage["eventType"] = "example.event";
  JsonObject eventData = eventMessage.createNestedObject("data");
  eventData["key"] = "value";

  // Serialize the event message to a JSON string
  String jsonMessage;
  serializeJson(eventMessage, jsonMessage);

  // Publish the event message to Event Grid
  mqttClient.publish(eventGridTopic, jsonMessage.c_str());
}

please helpme

Answer 1

Read this series and see how to do it:

https://medium.com/@alonfliess/the-internet-of-things-the-maturity-phase-d7e8d9a06fdd

https://medium.com/@alonfliess/article-two-of-five-azure-event-grid-mqtt-broker-in-practice-89918f8287d2

https://medium.com/@alonfliess/article-three-of-five-automate-the-creation-of-the-azure-event-grid-mqtt-broker-and-clients-9d27fc240184

https://medium.com/@alonfliess/article-4-of-5-the-cloud-service-code-6fb589fa4ee5

https://medium.com/@alonfliess/article-5-of-5-completing-the-journey-from-esp32-to-the-cloud-and-back-d540a10da293