Added initial interfaces and some sensors implementing them

src/mb704x/mb704x.cxx

@@ -47,3 +47,8 @@ int MB704X::getRange()
 {
     return mb704x_get_range(m_mb704x);
 }
+
+int MB704X::getDistance()
+{
+    return getRange();
+}

src/mb704x/mb704x.hpp

@@ -25,6 +25,7 @@
 
 #include <string>
 #include <iostream>
+#include <interfaces/iDistance.hpp>
 
 #include <stdlib.h>
 #include <unistd.h>
@@ -58,7 +59,7 @@ namespace upm {
      * @snippet mb704x.cxx Interesting
      */
 
-    class MB704X {
+    class MB704X : virtual public iDistance {
     public:
 
         /**
@@ -84,7 +85,12 @@ namespace upm {
          */
         int getRange();
 
-
+        /**
+         * Gets the distance to the object in cm
+         *
+         * @return Distance to the object in cm
+         */
+        virtual int getDistance();
     protected:
         // mb704x device context
         mb704x_context m_mb704x;