diff --git a/platformio.ini b/platformio.ini
index 1af159f..d503fed 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -47,7 +47,7 @@ lib_deps =
 ;    SDS011 sensor Library
 ;    Nova Fitness Sds dust sensors library
     https://github.com/lewapek/sds-dust-sensors-arduino-library.git
-;    ArduinoJSON
+    ArduinoJSON
 
 monitor_speed = 115200
 upload_speed = 115200
diff --git a/src/main.cpp b/src/main.cpp
index 42234cc..42a9cdc 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -32,6 +32,8 @@
 #include "network/XD0OTA.h"
 #include "network/XD0MQTT.h"
 
+#include <ArduinoJson.h>
+
 #include "SensorHistory.h"
 
 #include "icons.h"
@@ -57,8 +59,10 @@ SdsDustSensor sds(Serial2);
 Adafruit_VEML6075 uv = Adafruit_VEML6075();
 BH1750 lightMeter;
 
-XD0OTA ota("esp32-weatherstation");
+constexpr unsigned int JSON_BUF_LEN = 512;
+constexpr unsigned int JSON_CAPACITY = JSON_OBJECT_SIZE(16) + 0*JSON_ARRAY_SIZE(2) + 120;
 XD0MQTT mqtt;
+XD0OTA ota("esp32-weatherstation");
 
 struct __attribute__((packed)) network_t {
   uint32_t ip;
@@ -374,9 +378,11 @@ void getSensorMeasurements() {
 }
 
 
-void receiveMqtt(const char* topic, const char* data) {
+void receiveMqtt(const char* topic, const char* data, int data_len) {
     sensor_readings_t* sensor = NULL;
 
+    ESP_LOGI(TAG, "received MQTT message on subscribed topic %s", topic);
+
     if (strstr(topic, "thomas/sensor/a4cf1211c3e4") == topic) {
       sensor = &sensors_a4cf1211c3e4;
     } else if (strstr(topic, "thomas/sensor/246f28d1fa5c") == topic) {
@@ -390,8 +396,32 @@ void receiveMqtt(const char* topic, const char* data) {
     char* topic_last = strrchr(topic, '/');
 
     if (topic_last && sensor) {
-      if (strcmp("/temperature", topic_last) == 0) {
+      if (strcmp("/json", topic_last) == 0) {
+        StaticJsonDocument<JSON_CAPACITY+120> jsonDoc;
+        DeserializationError err = deserializeJson(jsonDoc, data, data_len);
+        if (err) {
+          ESP_LOGW(TAG, "Error parsing JSON, code: %s", err.c_str());
+        } else {
+          // got json
+          sensor->temperature = jsonDoc["temperature"].as<float>();
+          sensor->humidity = jsonDoc["humidity"].as<float>();
+          sensor->pressure = jsonDoc["pressure"].as<float>();
+          sensor->voc = jsonDoc["voc"].as<uint32_t>();
+          sensor->lux = jsonDoc["lux"].as<float>();
+          sensor->uvi = jsonDoc["uvi"].as<float>();
+          sensor->uva = jsonDoc["uva"].as<float>();
+          sensor->uvb = jsonDoc["uvb"].as<float>();
+          sensor->pm10 = jsonDoc["pm10"].as<float>();
+          sensor->pm25 = jsonDoc["pm2.5"].as<float>();
+          sensor->battery = jsonDoc["voltage"].as<int>();
+          sensor->rssi = jsonDoc["rssi"].as<int8_t>();
+          sensor->lastUpdate = jsonDoc["timestamp"].as<time_t>();
+          ESP_LOGI(TAG, "got new values from %s, timestamp: %lu", topic, sensor->lastUpdate);
+          ESP_LOGI(TAG, "%lu seconds ago", topic, getTimestamp() - sensor->lastUpdate);
+        }
+      } else if (strcmp("/temperature", topic_last) == 0) {
         sensor->temperature = atof(data);
+        sensor->lastUpdate = getTimestamp();
       } else if (strcmp("/humidity", topic_last) == 0) {
         sensor->humidity = atof(data);
       } else if (strcmp("/pressure", topic_last) == 0) {
@@ -411,7 +441,6 @@ void receiveMqtt(const char* topic, const char* data) {
       } else if (strcmp("/voc", topic_last) == 0) {
         sensor->voc = atof(data);
       }
-      sensor->lastUpdate = getTimestamp(); // ToDo
     }
 }
 
@@ -426,6 +455,7 @@ void displayValues() {
   char timeStr[40];
   getTime(timeStr, sizeof(timeStr), "%d. %b %Y  %H:%M:%S");
 
+  ESP_LOGD(TAG, "displayValues()");
 
   if (display.epd2.hasFastPartialUpdate) {
     display.setPartialWindow(0, 0, display.width(), display.height());
@@ -608,21 +638,57 @@ void displayValues() {
 
 
 void sendValues() {
+  for (int tries=0; mqtt.isConnected() == false && tries < 10; tries++) {
+    ESP_LOGD(TAG, "waiting for mqtt connection");
+    delay(300);
+  }
+
+  /* send values MQTT JSON */
+  char buf[JSON_BUF_LEN];
+  StaticJsonDocument<JSON_CAPACITY> jsonDoc;
+  if (sensors_active.bme280 || sensors_active.bme680) {
+    jsonDoc["temperature"] = sensor_readings.temperature;
+    jsonDoc["humidity"] = sensor_readings.humidity;
+    jsonDoc["pressure"] = sensor_readings.pressure;
+  }
+  if (sensors_active.bme680) {
+    jsonDoc["voc"] = sensor_readings.voc;
+  }
+  if (sensors_active.light) {
+    jsonDoc["lux"] = sensor_readings.lux;
+  }
+  if (sensors_active.uv) {
+    jsonDoc["uvi"] = sensor_readings.uvi;
+    jsonDoc["uva"] = sensor_readings.uva;
+    jsonDoc["uvb"] = sensor_readings.uvb;
+  }
+  if (sensors_active.sds) {
+    jsonDoc["pm10"] = sensor_readings.pm10;
+    jsonDoc["pm2.5"] = sensor_readings.pm25;
+  }
+  jsonDoc["voltage"] = sensor_readings.battery;
+  jsonDoc["rssi"] = sensor_readings.rssi;
+  jsonDoc["timestamp"] = sensor_readings.lastUpdate;
+  serializeJson(jsonDoc, buf, JSON_BUF_LEN);
+  String topic_json = String("thomas/sensor/") + ota.getMAC() + String("/json");
+  mqtt.publish(topic_json.c_str(), buf, strlen(buf), 1, 1);
+  delay(10);
+
     /* send values MQTT */
   if (sensors_active.bme280 || sensors_active.bme680) {
     String topic_temperature = String("thomas/sensor/") + ota.getMAC() + String("/temperature");
     String topic_humidity = String("thomas/sensor/") + ota.getMAC() + String("/humidity");
     String topic_pressure = String("thomas/sensor/") + ota.getMAC() + String("/pressure");
-    mqtt.publishf2(topic_temperature.c_str(), 1, 1, "%.2f", sensor_readings.temperature);
+    mqtt.publishf(topic_temperature.c_str(), "%.2f", sensor_readings.temperature);
     delay(10);
-    mqtt.publishf2(topic_humidity.c_str(), 1, 1, "%.2f", sensor_readings.humidity);
+    mqtt.publishf(topic_humidity.c_str(), "%.2f", sensor_readings.humidity);
     delay(10);
-    mqtt.publishf2(topic_pressure.c_str(), 1, 1, "%.2f", sensor_readings.pressure);
+    mqtt.publishf(topic_pressure.c_str(), "%.2f", sensor_readings.pressure);
     delay(10);
   }
   if (sensors_active.bme680) {
     String topic_voc = String("thomas/sensor/") + ota.getMAC() + String("/voc");
-    mqtt.publishf2(topic_voc.c_str(), 1, 1, "%.2f", sensor_readings.voc / 1000.0F);
+    mqtt.publishf(topic_voc.c_str(), "%.2f", sensor_readings.voc / 1000.0F);
     delay(10);
   }
 
@@ -630,35 +696,35 @@ void sendValues() {
     String topic_uvi = String("thomas/sensor/") + ota.getMAC() + String("/uvi");
     String topic_uva = String("thomas/sensor/") + ota.getMAC() + String("/uva");
     String topic_uvb = String("thomas/sensor/") + ota.getMAC() + String("/uvb");
-    mqtt.publishf2(topic_uvi.c_str(), 1, 1, "%.2f", sensor_readings.uvi);
-    mqtt.publishf2(topic_uva.c_str(), 1, 1, "%.2f", sensor_readings.uva);
-    mqtt.publishf2(topic_uvb.c_str(), 1, 1, "%.2f", sensor_readings.uvb);
+    mqtt.publishf(topic_uvi.c_str(), "%.2f", sensor_readings.uvi);
+    mqtt.publishf(topic_uva.c_str(), "%.2f", sensor_readings.uva);
+    mqtt.publishf(topic_uvb.c_str(), "%.2f", sensor_readings.uvb);
     delay(10);
   }
 
   if (sensors_active.light) {
     String topic_lux = String("thomas/sensor/") + ota.getMAC() + String("/lux");
-    mqtt.publishf2(topic_lux.c_str(), 1, 1, "%.2f", sensor_readings.lux);
+    mqtt.publishf(topic_lux.c_str(), "%.2f", sensor_readings.lux);
     delay(10);
   }
 
   if (sensors_active.sds) {
     String topic_pm10 = String("thomas/sensor/") + ota.getMAC() + String("/pm10");
     String topic_pm25 = String("thomas/sensor/") + ota.getMAC() + String("/pm25");
-    mqtt.publishf2(topic_pm10.c_str(), 1, 1, "%.2f", sensor_readings.pm10);
-    mqtt.publishf2(topic_pm25.c_str(), 1, 1, "%.2f", sensor_readings.pm25);
+    mqtt.publishf(topic_pm10.c_str(), "%.2f", sensor_readings.pm10);
+    mqtt.publishf(topic_pm25.c_str(), "%.2f", sensor_readings.pm25);
     delay(10);
   }
 
   {
     String topic_battery = String("thomas/sensor/") + ota.getMAC() + String("/battery");
-    mqtt.publishf2(topic_battery.c_str(), 1, 1, "%.2f", (sensor_readings.battery/4096.0)*2*3.42);
+    mqtt.publishf(topic_battery.c_str(), "%.2f", (sensor_readings.battery/4096.0)*2*3.42);
     delay(10);
   }
 
   {
     String topic_rssi = String("thomas/sensor/") + ota.getMAC() + String("/rssi");
-    mqtt.publishf2(topic_rssi.c_str(), 1, 1, "%d", sensor_readings.rssi);
+    mqtt.publishf(topic_rssi.c_str(), "%d", sensor_readings.rssi);
     delay(10);
   }
 
@@ -803,10 +869,10 @@ void setup()
   ESP_LOGD(TAG, "connecting to MQTT");
   mqtt.begin();
 
-  if (!ota.getMAC().equals("a4cf1211c3e4")) mqtt.subscribe("thomas/sensor/a4cf1211c3e4/#", receiveMqtt);
-  if (!ota.getMAC().equals("246f28d1fa5c")) mqtt.subscribe("thomas/sensor/246f28d1fa5c/#", receiveMqtt);
-  if (!ota.getMAC().equals("246f28d1a080")) mqtt.subscribe("thomas/sensor/246f28d1a080/#", receiveMqtt);
-  if (!ota.getMAC().equals("246f28d1eff4")) mqtt.subscribe("thomas/sensor/246f28d1eff4/#", receiveMqtt);
+  if (!ota.getMAC().equals("a4cf1211c3e4")) mqtt.subscribe("thomas/sensor/a4cf1211c3e4/json", receiveMqtt);
+  if (!ota.getMAC().equals("246f28d1fa5c")) mqtt.subscribe("thomas/sensor/246f28d1fa5c/json", receiveMqtt);
+  if (!ota.getMAC().equals("246f28d1a080")) mqtt.subscribe("thomas/sensor/246f28d1a080/json", receiveMqtt);
+  if (!ota.getMAC().equals("246f28d1eff4")) mqtt.subscribe("thomas/sensor/246f28d1eff4/json", receiveMqtt);
 
   /* temp: publish version */
   String topic_version = String("thomas/sensor/") + ota.getMAC() + String("/version");
@@ -842,8 +908,9 @@ void loop()
   }
 
   getSensorMeasurements();
-  displayValues();
   sendValues();
+  delay(1);
+  displayValues();
 
   int runtime = millis()/1000;
   if (runtime < 0 || runtime >= TIME_TO_SLEEP) runtime = 0;