mqtt publish float values

src/main.cpp

@@ -197,17 +197,13 @@ void sendValues() {
     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");
-    char temperature[8]; sprintf(temperature, "%.2f", sensor_readings.temperature);
-    char humidity[7]; sprintf(humidity, "%.2f", sensor_readings.humidity);
-    char pressure[8]; sprintf(pressure, "%.2f", sensor_readings.pressure / 100.0F);
-    mqtt.publish(topic_temperature.c_str(), temperature, strlen(temperature));
-    mqtt.publish(topic_humidity.c_str(), humidity, strlen(humidity));
-    mqtt.publish(topic_pressure.c_str(), pressure, strlen(pressure));
+    mqtt.publish(topic_temperature.c_str(), sensor_readings.temperature, "%.2f");
+    mqtt.publish(topic_humidity.c_str(), sensor_readings.humidity, "%.2f");
+    mqtt.publish(topic_pressure.c_str(), sensor_readings.pressure / 100.0F, "%.2f");
   }
   if (bme680_active) {
     String topic_voc = String("thomas/sensor/") + ota.getMAC() + String("/voc");
-    char voc[12]; sprintf(voc, "%.2f", sensor_readings.voc / 1000.0F);
-    mqtt.publish(topic_voc.c_str(), voc, strlen(voc));
+    mqtt.publish(topic_voc.c_str(), sensor_readings.voc / 1000.0F, "%.2f");
   }
   if (!bme280_active && !bme680_active) {
     String topic_temperature = String("thomas/sensor/") + ota.getMAC() + String("/temperature");
@@ -220,21 +216,16 @@ 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");
-    char uvi[10]; sprintf(uvi, "%.2f", sensor_readings.uvi);
-    char uva[10]; sprintf(uva, "%.2f", sensor_readings.uva);
-    char uvb[10]; sprintf(uvb, "%.2f", sensor_readings.uvb);
-    mqtt.publish(topic_uvi.c_str(), uvi, strlen(uvi));
-    mqtt.publish(topic_uva.c_str(), uva, strlen(uva));
-    mqtt.publish(topic_uvb.c_str(), uvb, strlen(uvb));
+    mqtt.publish(topic_uvi.c_str(), sensor_readings.uvi, "%.2f");
+    mqtt.publish(topic_uva.c_str(), sensor_readings.uva, "%.2f");
+    mqtt.publish(topic_uvb.c_str(), sensor_readings.uvb, "%.2f");
   }
 
   if (sds_active) {
     String topic_pm10 = String("thomas/sensor/") + ota.getMAC() + String("/pm10");
-    char pm10[10]; sprintf(pm10, "%.2f", sensor_readings.pm10);
     String topic_pm25 = String("thomas/sensor/") + ota.getMAC() + String("/pm25");
-    char pm25[10]; sprintf(pm25, "%.2f", sensor_readings.pm25);
-    mqtt.publish(topic_pm10.c_str(), pm10, strlen(pm10));
-    mqtt.publish(topic_pm25.c_str(), pm25, strlen(pm25));
+    mqtt.publish(topic_pm10.c_str(), sensor_readings.pm10, "%.2f");
+    mqtt.publish(topic_pm25.c_str(), sensor_readings.pm25, "%.2f");
   }
 
 }

src/network/XD0MQTT.cpp

@@ -115,6 +115,13 @@ bool XD0MQTT::publish(const char* topic, const char* data, int len, int qos, int
   ESP_LOGI(TAG, "sent publish successful, msg_id=%d", msg_id);
 }
 
+bool XD0MQTT::publish(const char* topic, const float data, const char* format, int qos, int retain) {
+  char data_str[64];
+  sprintf(data_str, format, data);
+  int msg_id = esp_mqtt_client_publish(client, topic, data_str, strlen(data_str), qos, retain);
+  ESP_LOGI(TAG, "sent publish successful, msg_id=%d", msg_id);
+}
+
 bool XD0MQTT::subscribe(const char* topic, const cb_t &cb, int qos) {
     subscription_t subscription = {topic, cb, qos};
     subscriptions_.push_back(subscription);

src/network/XD0MQTT.h

@@ -30,6 +30,7 @@ class XD0MQTT {
     XD0MQTT(void);
     bool begin(void);
     bool publish(const char* topic, const char* data, int len, int qos=1, int retain=0);
+    bool publish(const char* topic, const float data, const char* format, int qos=1, int retain=0);
     bool subscribe(const char* topic, const cb_t &cb, int qos=1);
     bool unsubscribe(const char* topic);
     esp_err_t mqtt_event_handler_cb(esp_mqtt_event_handle_t event);