diff --git a/firmware/config_user.h.example b/firmware/config_user.h.example
index c209cd5..d39911a 100755
--- a/firmware/config_user.h.example
+++ b/firmware/config_user.h.example
@@ -31,6 +31,7 @@ String DEVICE_NAME = "weatherstation";
 #define SENSOR_BME280
 //#define SENSOR_BMP280
 #define SENSOR_BATTERY
+//#define SENSOR_USB_VOLTAGE
 
 //#define BAT_PINS_D34
 
diff --git a/firmware/constants.h b/firmware/constants.h
index cab8a7d..aea0fe1 100644
--- a/firmware/constants.h
+++ b/firmware/constants.h
@@ -7,7 +7,7 @@
 #define SENSOR_LIGHT          2
 #define SENSOR_WINDSPEED      3
 #define SENSOR_PRESSURE       4
-#define SENSOR_BAT_VOLTAGE    5
+#define SENSOR_VOLTAGE        5
 #define SENSOR_ESAVEMODE      6
 #define SENSOR_BATCHARGESTATE 7
 
@@ -37,6 +37,7 @@ const String hb_ws_msg_humi      = "\"humidity\": ";
 const String hb_ws_msg_light     = "\"lightlevel\": ";
 const String hb_ws_msg_windspeed = "\"windspeed\": ";
 const String hb_ws_msg_pressure  = "\"pressure\": ";
+const String hb_ws_msg_voltage   = "\"voltage\": ";
 const String hb_ws_msg_timestamp = "\"timestamp\": ";
 const String hb_ws_msg_valid     = "\"valid\": ";
 const String hb_ws_msg_end       = "}";
diff --git a/firmware/firmware.ino b/firmware/firmware.ino
index e5d39b1..768c5b4 100644
--- a/firmware/firmware.ino
+++ b/firmware/firmware.ino
@@ -241,9 +241,12 @@ float readSensors(uint8_t s) {
 #endif
       break;
 
-    case SENSOR_BAT_VOLTAGE:
+    case SENSOR_VOLTAGE:
 #ifdef SENSOR_BATTERY
       ret = battery_voltage();
+#endif
+#ifdef SENSOR_USB_VOLTAGE
+      ret = usb_voltage();
 #endif
       break;
 
@@ -694,8 +697,10 @@ void _fsm_loop()
 
 //*************************************************************************//
 
+
 void _battery_mode_main() {
 
+#ifdef SENSOR_BATTERY
   if (energySavingMode() == 1) {
     // Disable expensive tasks
     //debug("read of wind sensor because of low battery disabled");
@@ -705,6 +710,7 @@ void _battery_mode_main() {
     //debug("read of wind sensor because of high battery enabled");
     do_not_read_windsensor = false;
   }
+#endif
 
   for (uint8_t i = 0; i < VALUES; i++) {
     currentSensorData[i] = readSensors(i);
@@ -736,7 +742,7 @@ void logToSerial(float sensorValues[]) {
   Serial.println("Light: " + String(sensorValues[SENSOR_LIGHT]) + " Lux");
   Serial.println("Windspeed: " + String(sensorValues[SENSOR_WINDSPEED]) + " km/h");
   Serial.println("Pressure: " + String(sensorValues[SENSOR_PRESSURE]) + " hPa");
-  Serial.println("Bat Voltage: " + String(sensorValues[SENSOR_BAT_VOLTAGE]) + " V");
+  Serial.println("Bat Voltage: " + String(sensorValues[SENSOR_VOLTAGE]) + " V");
   Serial.println("Bat charge state: " + String(sensorValues[SENSOR_BATCHARGESTATE]));
   Serial.println("Energy saving: " + String(sensorValues[SENSOR_ESAVEMODE]));
 }
@@ -765,6 +771,9 @@ String getJsonData()
               hb_ws_msg_pressure +
               String(currentSensorData[SENSOR_PRESSURE], 2) +
               ", " +
+              hb_ws_msg_voltage +
+              String(currentSensorData[SENSOR_VOLTAGE], 2) +
+              ", " +
               hb_ws_msg_timestamp +
               String(millis()) +
               ", " +
diff --git a/firmware/influxdb.ino b/firmware/influxdb.ino
index a3d2174..fd4ab62 100644
--- a/firmware/influxdb.ino
+++ b/firmware/influxdb.ino
@@ -150,10 +150,10 @@ void pushToInfluxDB(String device, float sensorValues[]) {
     sensor.addField("pressure", sensorValues[SENSOR_PRESSURE]);
     _writePoint();
   }
-  if (!(isnan(sensorValues[SENSOR_BAT_VOLTAGE])))
+  if (!(isnan(sensorValues[SENSOR_VOLTAGE])))
   {
     sensor.clearFields();
-    sensor.addField("batvoltage", sensorValues[SENSOR_BAT_VOLTAGE]);
+    sensor.addField("batvoltage", sensorValues[SENSOR_VOLTAGE]);
     _writePoint();
   }
   if (!(isnan(sensorValues[SENSOR_ESAVEMODE])))
diff --git a/firmware/sensor_battery.ino b/firmware/sensor_battery.ino
index a2e7745..dfff287 100644
--- a/firmware/sensor_battery.ino
+++ b/firmware/sensor_battery.ino
@@ -2,6 +2,7 @@ float _sensor_battery_saveMode = ENERGY_SAVE_MODE_DISABLED;
 uint16_t energySavingIterations = 0;
 
 // Copied from https://arduinodiy.wordpress.com/2016/12/25/monitoring-lipo-battery-voltage-with-wemos-d1-minibattery-shield-and-thingspeak/
+#ifdef SENSOR_BATTERY
 float battery_voltage() {
   // ESP8266 ADC pin input voltage range ist 0V .. 1V
   // The Wemos D1 mini does already contain a voltage divider circuit: A0(Wemos PCB) -- [220kOhm] -- ADC (ESP8266)-- [100kOhm] -- GND
@@ -49,3 +50,16 @@ int energySavingMode() {
 float isEnergySavingMode() {
   return _sensor_battery_saveMode;
 }
+#endif
+
+#ifdef SENSOR_USB_VOLTAGE
+float usb_voltage() {
+  // ESP8266 ADC pin input voltage range ist 0V .. 1V
+  // The Wemos D1 mini does already contain a voltage divider circuit: A0(Wemos PCB) -- [220kOhm] -- ADC (ESP8266)-- [100kOhm] -- GND
+  // The (+) pole of the battery is connected to the A0 pin of the Wemos board through a additional 300kOhm resistance.
+  // The USB voltage of 5V max is measured as 1.0V on ESP8266 ADC pin.
+  uint16_t raw = analogRead(A0);
+  float volt = raw / 1023.0;
+  return volt * 6.2;
+}
+#endif
diff --git a/firmware/webUpdater.ino b/firmware/webUpdater.ino
index f3b5b08..1fe5748 100644
--- a/firmware/webUpdater.ino
+++ b/firmware/webUpdater.ino
@@ -128,7 +128,7 @@ void showHTMLMain(void) {
 #endif
 #ifdef SHOW_SENSOR_DATA_ON_WEBUPDATER_MAIN_PAGE
                                       "<br><br><table>" TR_TD_START_STR
-                   + "temperature" + TD_TD_MID_STR + String(_webUpdater_sensValues[SENSOR_TEMPERATURE]) + TR_TD_END_STR TR_TD_START_STR + "humidity" + TD_TD_MID_STR + String(_webUpdater_sensValues[SENSOR_HUMIDITY]) + TR_TD_END_STR TR_TD_START_STR + "light" + TD_TD_MID_STR + String(_webUpdater_sensValues[SENSOR_LIGHT]) + TR_TD_END_STR TR_TD_START_STR + "windspeed" + TD_TD_MID_STR + String(_webUpdater_sensValues[SENSOR_WINDSPEED]) + TR_TD_END_STR TR_TD_START_STR + "pressure" + TD_TD_MID_STR + String(_webUpdater_sensValues[SENSOR_PRESSURE]) + TR_TD_END_STR TR_TD_START_STR + "batvoltage" + TD_TD_MID_STR + String(_webUpdater_sensValues[SENSOR_BAT_VOLTAGE]) + TR_TD_END_STR TR_TD_START_STR + "millis" + TD_TD_MID_STR + String(millis()) + TR_TD_END_STR TR_TD_START_STR + "valid" + TD_TD_MID_STR + String(wuValidData) + TR_TD_END_STR TR_TD_START_STR + "wifi rssi" + TD_TD_MID_STR + WiFi.RSSI() + TR_TD_END_STR TR_TD_START_STR + "wifi rec cnt" + TD_TD_MID_STR + String(_wifi_reconnect_cnt) + TR_TD_END_STR "</table>"
+                   + "temperature" + TD_TD_MID_STR + String(_webUpdater_sensValues[SENSOR_TEMPERATURE]) + TR_TD_END_STR TR_TD_START_STR + "humidity" + TD_TD_MID_STR + String(_webUpdater_sensValues[SENSOR_HUMIDITY]) + TR_TD_END_STR TR_TD_START_STR + "light" + TD_TD_MID_STR + String(_webUpdater_sensValues[SENSOR_LIGHT]) + TR_TD_END_STR TR_TD_START_STR + "windspeed" + TD_TD_MID_STR + String(_webUpdater_sensValues[SENSOR_WINDSPEED]) + TR_TD_END_STR TR_TD_START_STR + "pressure" + TD_TD_MID_STR + String(_webUpdater_sensValues[SENSOR_PRESSURE]) + TR_TD_END_STR TR_TD_START_STR + "batvoltage" + TD_TD_MID_STR + String(_webUpdater_sensValues[SENSOR_VOLTAGE]) + TR_TD_END_STR TR_TD_START_STR + "millis" + TD_TD_MID_STR + String(millis()) + TR_TD_END_STR TR_TD_START_STR + "valid" + TD_TD_MID_STR + String(wuValidData) + TR_TD_END_STR TR_TD_START_STR + "wifi rssi" + TD_TD_MID_STR + WiFi.RSSI() + TR_TD_END_STR TR_TD_START_STR + "wifi rec cnt" + TD_TD_MID_STR + String(_wifi_reconnect_cnt) + TR_TD_END_STR "</table>"
 #endif
 #ifndef DISABLE_WIFIMANAGER
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              "<br><br><br><br><br><a href=\"http://"
@@ -144,8 +144,16 @@ void showHTMLMain(void) {
 #ifdef HOMEBRIDGE_WEBSTAT
 void hb_webstat_send(void) {
 
-  String msg = hb_ws_msg_start + hb_ws_msg_temp + String(_webUpdater_sensValues[SENSOR_TEMPERATURE], 2) + ", " + hb_ws_msg_humi + String(_webUpdater_sensValues[SENSOR_HUMIDITY], 2) + ", " + hb_ws_msg_light + String(_webUpdater_sensValues[SENSOR_LIGHT], 0) +  // The light level for the homebridge-http-lux2 plugin is only able to parse integer values
-               ", " + hb_ws_msg_windspeed + String(_webUpdater_sensValues[SENSOR_WINDSPEED], 2) + ", " + hb_ws_msg_pressure + String(_webUpdater_sensValues[SENSOR_PRESSURE], 2) + ", " + hb_ws_msg_timestamp + String(millis()) + ", " + hb_ws_msg_valid + String(wuValidData) + hb_ws_msg_end;
+  String msg = hb_ws_msg_start +
+                   hb_ws_msg_temp + String(_webUpdater_sensValues[SENSOR_TEMPERATURE], 2) + ", " +
+                   hb_ws_msg_humi + String(_webUpdater_sensValues[SENSOR_HUMIDITY], 2) + ", " +
+                   hb_ws_msg_light + String(_webUpdater_sensValues[SENSOR_LIGHT], 0) + ", " + // The light level for the homebridge-http-lux2 plugin is only able to parse integer values
+                   hb_ws_msg_windspeed + String(_webUpdater_sensValues[SENSOR_WINDSPEED], 2) + ", " +
+                   hb_ws_msg_pressure + String(_webUpdater_sensValues[SENSOR_PRESSURE], 2) + ", " +
+                   hb_ws_msg_voltage + String(_webUpdater_sensValues[SENSOR_VOLTAGE], 2) + ", " +
+                   hb_ws_msg_timestamp + String(millis()) + ", " +
+                   hb_ws_msg_valid + String(wuValidData) +
+               hb_ws_msg_end;
 
   httpServer.send(200, "text/html", msg);
 }