Add option for humidity compensation

Author: thgeorgiou

src/hackair.cpp

@@ -178,3 +178,8 @@ void hackAIR::turnOff() {
 #endif
     }
 }
+
+void humidityCompensation(hackAirData &data, float humidity) {
+    data.pm25 = data.pm25 / (3.72f * (1 + 7 * (humidity / 100.0f)));
+    data.pm10 = data.pm10 / (3.72f * (1 + 7 * (humidity / 100.0f)));
+}

src/hackair.h

@@ -90,6 +90,11 @@ class hackAIR {
      */
     void turnOff();
 
+    /**
+     * Compensates the measurements for the given humidity
+     */
+    void humidityCompensation(hackAirData &data, float humidity);
+
 private:
     int _sensorType;
     long _lastTime;