Added iGas interface

Signed-off-by: Serban Waltter <serban.waltter@rinftech.com>
Signed-off-by: Mihai Tudor Panu <mihai.tudor.panu@intel.com>

src/groveo2/groveo2.hpp

@@ -25,6 +25,7 @@
 
 #include <string>
 #include <mraa/aio.h>
+#include <interfaces/iGas.hpp>
 
 namespace upm {
   /**
@@ -50,7 +51,7 @@ namespace upm {
    * @image html groveo2.jpg
    * @snippet groveo2.cxx Interesting
    */
-  class GroveO2 {
+  class GroveO2: virtual public iGas {
   public:
     /**
      * Grove O2 Oxygen Gas sensor constructor
@@ -69,6 +70,13 @@ namespace upm {
      */
     float voltageValue();
 
+    /**
+     * Measures O2 from the sensor
+     *
+     * @return Oxygen concentration as PPM
+     */
+    float getConcentration();
+
   private:
     mraa_aio_context m_aio;
   };