adding files

i2c_encoder/encoder.h

@@ -0,0 +1,64 @@
+ #ifndef __C_ROTARY_ENCODER_H__
+#define __C_ROTARY_ENCODER_H__
+
+#include <Arduino.h>
+
+class RotaryEncoder {
+    /*
+      wraps encoder setup and update functions in a class
+
+      !!! NOTE : user must call the encoders update method from an
+      interrupt function himself! i.e. user must attach an interrupt to the
+      encoder pin A and call the encoder update method from within the
+      interrupt
+
+      uses Arduino pull-ups on A & B channel outputs
+      turning on the pull-ups saves having to hook up resistors
+      to the A & B channel outputs
+
+      // ------------------------------------------------------------------------------------------------
+      // Example usage :
+      // ------------------------------------------------------------------------------------------------
+          #include "Encoder.h"
+
+          Encoder encoder(2, 4);
+
+          void setup() {
+              attachInterrupt(0, doEncoder, CHANGE);
+              Serial.begin (115200);
+              Serial.println("start");
+          }
+
+          void loop(){
+              // do some stuff here - the joy of interrupts is that they take care of themselves
+          }
+
+          void doEncoder(){
+              encoder.update();
+              Serial.println( encoder.getPosition() );
+          }
+      // ------------------------------------------------------------------------------------------------
+      // Example usage end
+      // ------------------------------------------------------------------------------------------------
+    */
+  public:
+
+    // constructor : sets pins as inputs and turns on pullup resistors
+
+    RotaryEncoder( const String& argName, int argClkPin, int argDtPin, int argPinMode = INPUT_PULLUP);
+	~RotaryEncoder() {};
+	
+    // call this from your interrupt function
+    void update();
+    int getPosition();
+    void clearPosition();
+
+  private:
+
+    String name;
+    volatile int position;
+    int clkPin;  // clock pin
+    int dtPin;   // direction pin
+};
+
+#endif // __C_ROTARY_ENCODER_H__