Add calculation of Wet-Bulb Globe Temperature (WBGT) and Wet-Bulb Tem…

…perature (#225)

* Added Natural Wet-Bulb and Wet-Bulb Globe Temperature calculations
* Added calculated WBGT (Wet Bulb Globe Temperature) to MQTT messages

examples/BresserWeatherSensorMQTT/BresserWeatherSensorMQTT.ino

@@ -121,6 +121,7 @@
 // 20240603 Modified for arduino-esp32 v3.0.0
 // 20241113 Added getting/setting of sensor include/exclude lists via MQTT
 // 20250127 Added Globe Thermometer Temperature (8-in-1 Weather Sensor)
+// 20250129 Added calculated WBGT (Wet Bulb Globe Temperature)
 //
 // ToDo:
 //
@@ -710,6 +711,12 @@ void publishWeatherdata(bool complete)
                 {
                     mqtt_payload2 += String(",\"perceived_temp_c\":") + JSON_FLOAT(String(perceived_temperature(weatherSensor.sensor[i].w.temp_c, weatherSensor.sensor[i].w.wind_avg_meter_sec, weatherSensor.sensor[i].w.humidity), 1));
                 }
+                if (weatherSensor.sensor[i].w.tglobe_ok)
+                {
+                    float t_wet = calcnaturalwetbulb(weatherSensor.sensor[i].w.temp_c, weatherSensor.sensor[i].w.humidity);
+                    float wbgt = calcwbgt(t_wet, weatherSensor.sensor[i].w.tglobe_c, weatherSensor.sensor[i].w.temp_c);
+                    mqtt_payload2 += String(",\"wgbt\":") + JSON_FLOAT(String(wbgt, 1));
+                }
             }
             if (weatherSensor.sensor[i].w.uv_ok || complete)
             {

examples/BresserWeatherSensorMQTTCustom/BresserWeatherSensorMQTTCustom.ino

@@ -121,6 +121,7 @@
 // 20240603 Modified for arduino-esp32 v3.0.0
 // 20241113 Added getting/setting of sensor include/exclude lists via MQTT
 // 20250127 Added Globe Thermometer Temperature (8-in-1 Weather Sensor)
+// 20250129 Added calculated WBGT (Wet Bulb Globe Temperature)
 //
 // ToDo:
 //
@@ -709,6 +710,12 @@ void publishWeatherdata(bool complete)
                 {
                     mqtt_payload2 += String(",\"perceived_temp_c\":") + JSON_FLOAT(String(perceived_temperature(weatherSensor.sensor[i].w.temp_c, weatherSensor.sensor[i].w.wind_avg_meter_sec, weatherSensor.sensor[i].w.humidity), 1));
                 }
+                if (weatherSensor.sensor[i].w.tglobe_ok)
+                {
+                    float t_wet = calcnaturalwetbulb(weatherSensor.sensor[i].w.temp_c, weatherSensor.sensor[i].w.humidity);
+                    float wbgt = calcwbgt(t_wet, weatherSensor.sensor[i].w.tglobe_c, weatherSensor.sensor[i].w.temp_c);
+                    mqtt_payload2 += String(",\"wgbt\":") + JSON_FLOAT(String(wbgt, 1));
+                }
             }
             if (weatherSensor.sensor[i].w.uv_ok || complete)
             {

examples/BresserWeatherSensorMQTTCustom/src/WeatherUtils.cpp

@@ -1,8 +1,12 @@
+#include <Arduino.h>
 #include <math.h>
-#include <string>
+#if defined(ESP32) || defined(ESP8266)
+  #include <string>
+#endif
 #include <string.h>
 #include "WeatherUtils.h"
 
+#if defined(ESP32) || defined(ESP8266)
 // Mapping of wind direction in degrees to text
 // Note: add your localization as desired
 const std::string COMPASS_POINTS[17] = {
@@ -24,6 +28,7 @@ char * winddir_flt_to_str(float dir, char * buf)
 
     return buf;
 };
+#endif
 
 //
 // Convert wind speed from meters per second to Beaufort
@@ -136,10 +141,41 @@ float calcheatindex(float celsius, float humidity) {
   return (-8.784695 + 1.61139411 * celsius + 2.338549 * humidity - 0.14611605 * celsius * humidity - 0.012308094 * celsius * celsius - 0.016424828 * humidity * humidity + 0.002211732 * celsius * celsius * humidity + 0.00072546 * celsius * humidity * humidity - 0.000003582 * celsius * celsius * humidity * humidity);
 }
 
+/* 
+ * Calculate natural wet bulb temperature
+ *
+ * Source:
+ * Stull, Roland B., 1950-. 
+ * “Wet-Bulb Temperature from Relative Humidity and Air Temperature.”
+ * A. American Meteorological Society, 2011. Web. 29 Jan. 2025. 
+ * https://open.library.ubc.ca/collections/facultyresearchandpublications/52383/items/1.0041967. 
+ * Faculty Research and Publications.
+ */
+float calcnaturalwetbulb(float temperature, float humidity)
+{
+  return temperature * atan(0.151977 * pow(humidity + 8.313659, 0.5))
+      + atan(temperature + humidity) 
+      - atan(humidity - 1.676331) 
+      + 0.00391838 * pow(humidity, 1.5) * atan(0.023101 * humidity) 
+      - 4.686035;
+}
+
+
+/*
+ * Calculate wet bulb globe temperature (WBGT)
+ *
+ * Source:
+ * https://en.wikipedia.org/wiki/Wet-bulb_globe_temperature
+ */
+float calcwbgt(float t_wet, float t_globe, float t_dry)
+{
+  return 0.7 * t_wet + 0.2 * t_globe + 0.1 * t_dry;
+}
+
 /*
  * Source:  https://myscope.net/hitzeindex-gefuehle-temperatur/
  *
- *          Valid for Valid for temperatures >= 27°C and humidity >=40%
+ *          Valid for temperatures >= 27°C and humidity >=40%
  */
 float calchumidex(float temperature, float humidity) {
   float e = (6.112 * pow(10,(7.5 * temperature/(237.7 + temperature))) * humidity/100); //vapor pressure

examples/BresserWeatherSensorMQTTCustom/src/WeatherUtils.h

@@ -1,6 +1,10 @@
 #if !defined(WEATHER_UTILS_H)
 #define WEATHER_UTILS_H
 
+#ifdef ARDUINO_ARCH_AVR
+  #include <stdint.h>
+#endif
+
 /*!
  * \brief Calculate dew point
  * 
@@ -19,7 +23,7 @@ float calcdewpoint(float celsius, float humidity);
  * \param celsius air temperature in °C
  * \param windspeed wind speed in km/h
  * 
- * \returns windchill tempoerature in °C
+ * \returns windchill temperature in °C
  */
 float calcwindchill(float celsius, float windspeed);
 
@@ -45,6 +49,28 @@ float calcheatindex(float celsius, float humidity);
  */
 float calchumidex(float temperature, float humidity);
 
+/*!
+ * \brief Calculate natural wet bulb temperature
+ *
+ * \param temperature Dry-bulb temperature (air temperature) in °C
+ * \param humidity relative humidity in %
+ * 
+ * \returns natural wet bulb temperature in °C
+ */
+float calcnaturalwetbulb(float temperature, float humidity);
+
+/*!
+ * \brief Calculate wet bulb globe temperature (WBGT)
+ *
+ * \param t_wet Natural wet-bulb temperature in °C
+ * \param t_globe Globe thermometer temperature (black globe thermometer) in °C
+ * \param t_dry Dry-bulb temperature (actual air temperature) in °C
+ * 
+ * \returns WBGT in °C
+ */
+float calcwbgt(float t_wet, float t_globe, float t_dry);
+
+
 /*!
  * \brief Calculate perceived temperature (feels-like temperature)
  * 

examples/BresserWeatherSensorMQTTWifiMgr/BresserWeatherSensorMQTTWifiMgr.ino

@@ -106,6 +106,7 @@
 // 20240603 Modified for arduino-esp32 v3.0.0
 // 20241113 Added getting/setting of sensor include/exclude lists via MQTT
 // 20250127 Added Globe Thermometer Temperature (8-in-1 Weather Sensor)
+// 20250129 Added calculated WBGT (Wet Bulb Globe Temperature)
 //
 // ToDo:
 //
@@ -893,6 +894,12 @@ void publishWeatherdata(bool complete)
                 {
                     mqtt_payload2 += String(",\"perceived_temp_c\":") + JSON_FLOAT(String(perceived_temperature(weatherSensor.sensor[i].w.temp_c, weatherSensor.sensor[i].w.wind_avg_meter_sec, weatherSensor.sensor[i].w.humidity), 1));
                 }
+                if (weatherSensor.sensor[i].w.tglobe_ok)
+                {
+                    float t_wet = calcnaturalwetbulb(weatherSensor.sensor[i].w.temp_c, weatherSensor.sensor[i].w.humidity);
+                    float wbgt = calcwbgt(t_wet, weatherSensor.sensor[i].w.tglobe_c, weatherSensor.sensor[i].w.temp_c);
+                    mqtt_payload2 += String(",\"wgbt\":") + JSON_FLOAT(String(wbgt, 1));
+                }
             }
             if (weatherSensor.sensor[i].w.uv_ok || complete)
             {

src/WeatherUtils.cpp

@@ -141,6 +141,37 @@ float calcheatindex(float celsius, float humidity) {
   return (-8.784695 + 1.61139411 * celsius + 2.338549 * humidity - 0.14611605 * celsius * humidity - 0.012308094 * celsius * celsius - 0.016424828 * humidity * humidity + 0.002211732 * celsius * celsius * humidity + 0.00072546 * celsius * humidity * humidity - 0.000003582 * celsius * celsius * humidity * humidity);
 }
 
+/* 
+ * Calculate natural wet bulb temperature
+ *
+ * Source:
+ * Stull, Roland B., 1950-. 
+ * “Wet-Bulb Temperature from Relative Humidity and Air Temperature.”
+ * A. American Meteorological Society, 2011. Web. 29 Jan. 2025. 
+ * https://open.library.ubc.ca/collections/facultyresearchandpublications/52383/items/1.0041967. 
+ * Faculty Research and Publications.
+ */
+float calcnaturalwetbulb(float temperature, float humidity)
+{
+  return temperature * atan(0.151977 * pow(humidity + 8.313659, 0.5))
+      + atan(temperature + humidity) 
+      - atan(humidity - 1.676331) 
+      + 0.00391838 * pow(humidity, 1.5) * atan(0.023101 * humidity) 
+      - 4.686035;
+}
+
+
+/*
+ * Calculate wet bulb globe temperature (WBGT)
+ *
+ * Source:
+ * https://en.wikipedia.org/wiki/Wet-bulb_globe_temperature
+ */
+float calcwbgt(float t_wet, float t_globe, float t_dry)
+{
+  return 0.7 * t_wet + 0.2 * t_globe + 0.1 * t_dry;
+}
+
 /*
  * Source:  https://myscope.net/hitzeindex-gefuehle-temperatur/
  *

src/WeatherUtils.h

@@ -49,6 +49,28 @@ float calcheatindex(float celsius, float humidity);
  */
 float calchumidex(float temperature, float humidity);
 
+/*!
+ * \brief Calculate natural wet bulb temperature
+ *
+ * \param temperature Dry-bulb temperature (air temperature) in °C
+ * \param humidity relative humidity in %
+ * 
+ * \returns natural wet bulb temperature in °C
+ */
+float calcnaturalwetbulb(float temperature, float humidity);
+
+/*!
+ * \brief Calculate wet bulb globe temperature (WBGT)
+ *
+ * \param t_wet Natural wet-bulb temperature in °C
+ * \param t_globe Globe thermometer temperature (black globe thermometer) in °C
+ * \param t_dry Dry-bulb temperature (actual air temperature) in °C
+ * 
+ * \returns WBGT in °C
+ */
+float calcwbgt(float t_wet, float t_globe, float t_dry);
+
+
 /*!
  * \brief Calculate perceived temperature (feels-like temperature)
  *