Update interface documentation

Signed-off-by: Serban Waltter <serban.waltter@rinftech.com>

include/interfaces/iDistance.hpp

@@ -40,7 +40,7 @@ namespace upm
     /**
      * Get distance from sensor
      * 
-     * @return Returns the distance
+     * @return Returns the distance in cm
      */
     virtual float getDistance() = 0;
     /**

include/interfaces/iDistanceInterrupter.hpp

@@ -33,6 +33,12 @@ namespace upm
   {
   public:
     virtual ~iDistanceInterrupter() {}
+
+    /**
+     * Determines if objected is detected
+     * 
+     * @return True if the sensor has detected an object
+     */
     virtual bool objectDetected() = 0;
   };
 }

include/interfaces/iHeartRate.hpp

@@ -37,7 +37,7 @@ namespace upm
     /**
      * Retrieve the computed heart rate
      *
-     * @return Computed heart rate
+     * @return Computed heart rate in BPM (beats per minute)
      */
     virtual int getHeartRate() = 0;
   };

include/interfaces/iHumidity.hpp

@@ -37,7 +37,7 @@ namespace upm
     /**
      * Measures humidity around the sensor
      * 
-     * @return Gets the humidity value
+     * @return Gets the relativ humidity value (%)
      */
     virtual float getHumidity() = 0;
   };

include/interfaces/iLight.hpp

@@ -37,7 +37,7 @@ namespace upm
         /**
          * Get luminance
          * 
-         * @return Luminance value
+         * @return Luminance value in lux
          */
         virtual float getLuminance() = 0;
     };

include/interfaces/iTemperature.hpp

@@ -42,7 +42,7 @@ namespace upm
     /**
      * Measures temperature
      * 
-     * @return temperature value
+     * @return temperature value in degrees Celsius
      */
     virtual float getTemperature() = 0;