HaloKeymind/lib/PsychicMqttClient/examples/SSL_CA_Cert/main.cpp

/**
 *   PsychicMqttClient
 *
 *   Simple Example for a minimal MQTT client using the PsychicMqttClient library.
 *
 *   Please change the ssid and pass to your actual WiFi credentials.
 *
 *   This example uses the public MQTT broker broker.hivemq.com,
 *   registers a onTopic callback function subscribed to a unique topic
 *   and publishes a message to that topic. The echoed message payload will be
 *   printed to the serial monitor.
 *
 */

#include <Arduino.h>
#include <WiFi.h>
#include <PsychicMqttClient.h>

const char ssid[] = "ssid"; // your network SSID (name)
const char pass[] = "pass"; // your network password

/**
 * ISRG Root X1 Certificate which is used by the public MQTT broker broker.hivemq.com
 */
const char *eclipse_root_ca = "-----BEGIN CERTIFICATE-----\n"
                              "MIIFazCCA1OgAwIBAgIRAIIQz7DSQONZRGPgu2OCiwAwDQYJKoZIhvcNAQELBQAw\n"
                              "TzELMAkGA1UEBhMCVVMxKTAnBgNVBAoTIEludGVybmV0IFNlY3VyaXR5IFJlc2Vh\n"
                              "cmNoIEdyb3VwMRUwEwYDVQQDEwxJU1JHIFJvb3QgWDEwHhcNMTUwNjA0MTEwNDM4\n"
                              "WhcNMzUwNjA0MTEwNDM4WjBPMQswCQYDVQQGEwJVUzEpMCcGA1UEChMgSW50ZXJu\n"
                              "ZXQgU2VjdXJpdHkgUmVzZWFyY2ggR3JvdXAxFTATBgNVBAMTDElTUkcgUm9vdCBY\n"
                              "MTCCAiIwDQYJKoZIhvcNAQEBBQADggIPADCCAgoCggIBAK3oJHP0FDfzm54rVygc\n"
                              "h77ct984kIxuPOZXoHj3dcKi/vVqbvYATyjb3miGbESTtrFj/RQSa78f0uoxmyF+\n"
                              "0TM8ukj13Xnfs7j/EvEhmkvBioZxaUpmZmyPfjxwv60pIgbz5MDmgK7iS4+3mX6U\n"
                              "A5/TR5d8mUgjU+g4rk8Kb4Mu0UlXjIB0ttov0DiNewNwIRt18jA8+o+u3dpjq+sW\n"
                              "T8KOEUt+zwvo/7V3LvSye0rgTBIlDHCNAymg4VMk7BPZ7hm/ELNKjD+Jo2FR3qyH\n"
                              "B5T0Y3HsLuJvW5iB4YlcNHlsdu87kGJ55tukmi8mxdAQ4Q7e2RCOFvu396j3x+UC\n"
                              "B5iPNgiV5+I3lg02dZ77DnKxHZu8A/lJBdiB3QW0KtZB6awBdpUKD9jf1b0SHzUv\n"
                              "KBds0pjBqAlkd25HN7rOrFleaJ1/ctaJxQZBKT5ZPt0m9STJEadao0xAH0ahmbWn\n"
                              "OlFuhjuefXKnEgV4We0+UXgVCwOPjdAvBbI+e0ocS3MFEvzG6uBQE3xDk3SzynTn\n"
                              "jh8BCNAw1FtxNrQHusEwMFxIt4I7mKZ9YIqioymCzLq9gwQbooMDQaHWBfEbwrbw\n"
                              "qHyGO0aoSCqI3Haadr8faqU9GY/rOPNk3sgrDQoo//fb4hVC1CLQJ13hef4Y53CI\n"
                              "rU7m2Ys6xt0nUW7/vGT1M0NPAgMBAAGjQjBAMA4GA1UdDwEB/wQEAwIBBjAPBgNV\n"
                              "HRMBAf8EBTADAQH/MB0GA1UdDgQWBBR5tFnme7bl5AFzgAiIyBpY9umbbjANBgkq\n"
                              "hkiG9w0BAQsFAAOCAgEAVR9YqbyyqFDQDLHYGmkgJykIrGF1XIpu+ILlaS/V9lZL\n"
                              "ubhzEFnTIZd+50xx+7LSYK05qAvqFyFWhfFQDlnrzuBZ6brJFe+GnY+EgPbk6ZGQ\n"
                              "3BebYhtF8GaV0nxvwuo77x/Py9auJ/GpsMiu/X1+mvoiBOv/2X/qkSsisRcOj/KK\n"
                              "NFtY2PwByVS5uCbMiogziUwthDyC3+6WVwW6LLv3xLfHTjuCvjHIInNzktHCgKQ5\n"
                              "ORAzI4JMPJ+GslWYHb4phowim57iaztXOoJwTdwJx4nLCgdNbOhdjsnvzqvHu7Ur\n"
                              "TkXWStAmzOVyyghqpZXjFaH3pO3JLF+l+/+sKAIuvtd7u+Nxe5AW0wdeRlN8NwdC\n"
                              "jNPElpzVmbUq4JUagEiuTDkHzsxHpFKVK7q4+63SM1N95R1NbdWhscdCb+ZAJzVc\n"
                              "oyi3B43njTOQ5yOf+1CceWxG1bQVs5ZufpsMljq4Ui0/1lvh+wjChP4kqKOJ2qxq\n"
                              "4RgqsahDYVvTH9w7jXbyLeiNdd8XM2w9U/t7y0Ff/9yi0GE44Za4rF2LN9d11TPA\n"
                              "mRGunUHBcnWEvgJBQl9nJEiU0Zsnvgc/ubhPgXRR4Xq37Z0j4r7g1SgEEzwxA57d\n"
                              "emyPxgcYxn/eR44/KJ4EBs+lVDR3veyJm+kXQ99b21/+jh5Xos1AnX5iItreGCc=\n"
                              "-----END CERTIFICATE-----\n";

/**
 * Create a PsychicMqttClient object
 */
PsychicMqttClient mqttClient;

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

    /**
     * Connect to the WiFi network with the given ssid and pass.
     */
    WiFi.begin(ssid, pass);

    Serial.printf("Connecting to WiFi %s .", ssid);
    while (WiFi.status() != WL_CONNECTED)
    {
        Serial.print(".");
        delay(500);
    }

    Serial.printf("\r\nConnected, IP address: %s \r\n", WiFi.localIP().toString().c_str());

    /**
     * Connect to the open MQTT broker broker.hivemq.com with SSL/TLS enryption.
     */
    mqttClient.setServer("mqtts://broker.hivemq.com");
    mqttClient.setCACert(eclipse_root_ca);

    /**
     * Lambda callback function for onTopic Event Handler
     *
     * Subscribes to the topic "{MAC-Address}/simple" with QoS 0.
     * The lambda callback function will be called when a message is received.
     */
    String topic = String(ESP.getEfuseMac()) + "/simple";

    mqttClient.onTopic(topic.c_str(), 0, [&](const char *topic, const char *payload, int retain, int qos, bool dup)
                       {
                        /**
                         * Using a lambda callback function is a very convenient way to handle the 
                         * received message. The function will be called when a message is received. 
                         * 
                         * The parameters are:
                         * - topic: The topic of the received message
                         * - payload: The payload of the received message
                         * - retain: The retain flag of the received message
                         * - qos: The qos of the received message
                         * - dup: The duplicate flag of the received message
                         * 
                         * It is important not to do any heavy calculations, hardware access, delays or 
                         * blocking code in the callback function.
                        */
                        Serial.printf("Received Topic: %s\r\n", topic);
                        Serial.printf("Received Payload: %s\r\n", payload); });

    /**
     * Connect to the MQTT broker
     */
    mqttClient.connect();

    /**
     * Wait blocking until the connection is established
     */
    while (!mqttClient.connected())
    {
        delay(500);
    }

    /**
     * Publish a message to the topic "{MAC-Address}/simple" with QoS 0 and retain flag 0.
     *
     * You can only publish messages after the connection is established.
     */
    mqttClient.publish(topic.c_str(), 0, 0, "Hello World!");
}

void loop()
{
    /**
     * Nothing to do here, the onTopic callback function will be called when a message is received.
     */
}