adding files

i2c_encoder/encoder.cpp

@@ -0,0 +1,28 @@
+#include "encoder.h"
+
+//  public:
+
+// constructor : sets pins as inputs and turns on pullup resistors
+RotaryEncoder::RotaryEncoder( const String& argName, int argClkPin, int argDtPin, int argPinMode) : name(argName), clkPin ( argClkPin), dtPin( argDtPin ) 
+{
+   // set pin a and b to be input with pull up enabled
+   pinMode(clkPin, argPinMode);
+   pinMode(dtPin, argPinMode);
+   
+   position = 0;
+}
+
+void RotaryEncoder::update(void) 
+{
+   digitalRead(dtPin) ? position++ : position--;
+}
+
+int RotaryEncoder::getPosition ()
+{
+   return position;
+}
+
+void RotaryEncoder::clearPosition()
+{
+   position = 0;
+}