diff --git a/platformio.ini b/platformio.ini
index dfcaf32..9bd14ea 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -10,6 +10,7 @@
 
 [env:lolin_d32_pro]
 platform = espressif32
+;platform = https://github.com/platformio/platform-espressif32.git#feature/stage
 framework = arduino
 board = lolin_d32_pro
 
@@ -22,6 +23,9 @@ build_flags =
     -DWIFI_PASSWD="\"${sysenv.WIFI_PASSWD}\""
     -DWIFI_SSID2="\"${sysenv.WIFI_SSID}\""
     -DWIFI_PASSWD2="\"${sysenv.WIFI_PASSWD}\""
+    -DMQTT_BROKER_URI="\"${sysenv.MQTT_BROKER_URI}\""
+    -DMQTT_USERNAME="\"${sysenv.MQTT_USERNAME}\""
+    -DMQTT_PASSWORD="\"${sysenv.MQTT_PASSWORD}\""
 
 lib_deps =
     GxEPD2
diff --git a/src/XD0MQTT.cpp b/src/XD0MQTT.cpp
new file mode 100644
index 0000000..9688835
--- /dev/null
+++ b/src/XD0MQTT.cpp
@@ -0,0 +1,105 @@
+#include "XD0MQTT.h"
+
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <string.h>
+#include "esp_wifi.h"
+#include "esp_system.h"
+#include "nvs_flash.h"
+#include "esp_event.h"
+#include "tcpip_adapter.h"
+
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include "freertos/semphr.h"
+#include "freertos/queue.h"
+
+#include "lwip/sockets.h"
+#include "lwip/dns.h"
+#include "lwip/netdb.h"
+
+#include "esp_log.h"
+#include "mqtt_client.h"
+#include "esp_tls.h"
+
+static const char *TAG = "MQTT";
+
+XD0MQTT::XD0MQTT() {}
+
+static esp_err_t mqtt_event_handler_cb(esp_mqtt_event_handle_t event)
+{
+    esp_mqtt_client_handle_t client = event->client;
+    int msg_id;
+    //int mbedtls_err; esp_err_t err;
+    // your_context_t *context = event->context;
+    switch (event->event_id) {
+        case MQTT_EVENT_CONNECTED:
+            ESP_LOGI(TAG, "MQTT_EVENT_CONNECTED");
+            msg_id = esp_mqtt_client_subscribe(client, "/topic/qos0", 0);
+            ESP_LOGI(TAG, "sent subscribe successful, msg_id=%d", msg_id);
+
+            msg_id = esp_mqtt_client_subscribe(client, "/topic/qos1", 1);
+            ESP_LOGI(TAG, "sent subscribe successful, msg_id=%d", msg_id);
+
+            msg_id = esp_mqtt_client_unsubscribe(client, "/topic/qos1");
+            ESP_LOGI(TAG, "sent unsubscribe successful, msg_id=%d", msg_id);
+            break;
+        case MQTT_EVENT_DISCONNECTED:
+            ESP_LOGI(TAG, "MQTT_EVENT_DISCONNECTED");
+            break;
+
+        case MQTT_EVENT_SUBSCRIBED:
+            ESP_LOGI(TAG, "MQTT_EVENT_SUBSCRIBED, msg_id=%d", event->msg_id);
+            msg_id = esp_mqtt_client_publish(client, "/topic/qos0", "data", 0, 0, 0);
+            ESP_LOGI(TAG, "sent publish successful, msg_id=%d", msg_id);
+            break;
+        case MQTT_EVENT_UNSUBSCRIBED:
+            ESP_LOGI(TAG, "MQTT_EVENT_UNSUBSCRIBED, msg_id=%d", event->msg_id);
+            break;
+        case MQTT_EVENT_PUBLISHED:
+            ESP_LOGI(TAG, "MQTT_EVENT_PUBLISHED, msg_id=%d", event->msg_id);
+            break;
+        case MQTT_EVENT_DATA:
+            ESP_LOGI(TAG, "MQTT_EVENT_DATA");
+            printf("TOPIC=%.*s\r\n", event->topic_len, event->topic);
+            printf("DATA=%.*s\r\n", event->data_len, event->data);
+            break;
+        case MQTT_EVENT_ERROR:
+            ESP_LOGI(TAG, "MQTT_EVENT_ERROR");
+            //mbedtls_err = 0;
+            //err = esp_tls_get_and_clear_last_error(event->error_handle, &mbedtls_err, NULL);
+            //ESP_LOGI(TAG, "Last esp error code: 0x%x", err);
+            //ESP_LOGI(TAG, "Last mbedtls failure: 0x%x", mbedtls_err);
+            break;
+        default:
+            ESP_LOGI(TAG, "Other event id:%d", event->event_id);
+            break;
+    }
+    return ESP_OK;
+}
+
+//static void mqtt_event_handler(void *handler_args, esp_event_base_t base, int32_t event_id, void *event_data) {
+  static esp_err_t mqtt_event_handler(esp_mqtt_event_handle_t event) {
+    esp_mqtt_client_handle_t client = event->client;
+    mqtt_event_handler_cb(event);
+    //ESP_LOGD(TAG, "Event dispatched from event loop base=%s, event_id=%d", base, event_id);
+    //mqtt_event_handler_cb(event_data);
+}
+
+bool XD0MQTT::begin(void) {
+    esp_mqtt_client_config_t mqtt_cfg;
+        mqtt_cfg.uri = MQTT_BROKER_URI;
+        mqtt_cfg.event_handle = mqtt_event_handler;
+        mqtt_cfg.cert_pem = (const char *)rootCACertificate;
+        mqtt_cfg.username = MQTT_USERNAME;
+        mqtt_cfg.password = MQTT_PASSWORD;
+        mqtt_cfg.user_context = (void*)this;
+
+    ESP_LOGI(TAG, "[APP] Free memory: %d bytes", esp_get_free_heap_size());
+    esp_mqtt_client_handle_t client = esp_mqtt_client_init(&mqtt_cfg);
+    //esp_mqtt_client_register_event(client, ESP_EVENT_ANY_ID, mqtt_event_handler, client);
+    esp_mqtt_client_start(client);
+
+    return true;
+}
diff --git a/src/XD0MQTT.h b/src/XD0MQTT.h
new file mode 100644
index 0000000..245cb03
--- /dev/null
+++ b/src/XD0MQTT.h
@@ -0,0 +1,46 @@
+#ifndef _XD0MQTT_H
+#define _XD0MQTT_H
+
+#include <Arduino.h>
+
+class XD0MQTT {
+  public:
+    XD0MQTT(void);
+    bool begin(void);
+  private:
+    // openssl s_client -showcerts -connect home.xd0.de:8883 </dev/null 2>/dev/null|openssl x509 -outform PEM >mqtt_xd0.de.pem
+    const char* rootCACertificate = \
+      "-----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";
+};
+
+#endif /* _XD0MQTT_H */