Added simple example

examples/SurfaceDial/surface_dial.ino

@@ -0,0 +1,67 @@
+#include "HID-Project.h"
+
+int pinA = 2;
+int pinB = 3;
+
+int pinButton = 4;
+
+volatile bool previousButtonValue = false;
+
+volatile int previous = 0;
+volatile int counter = 0;
+
+void setup() {
+  pinMode(pinA, INPUT_PULLUP); 
+  pinMode(pinB, INPUT_PULLUP);
+
+  pinMode(pinButton, INPUT_PULLUP);
+
+  attachInterrupt(digitalPinToInterrupt(pinA), changed, CHANGE); 
+  attachInterrupt(digitalPinToInterrupt(pinB), changed, CHANGE);
+  
+  SurfaceDial.begin();
+}
+
+void changed() {
+  int A = digitalRead(pinA); 
+  int B = digitalRead(pinB);
+
+  int current = (A << 1) | B;
+  int combined  = (previous << 2) | current;
+   
+  if(combined == 0b0010 || 
+     combined == 0b1011 ||
+     combined == 0b1101 || 
+     combined == 0b0100) {
+    counter++;
+  }
+   
+  if(combined == 0b0001 ||
+     combined == 0b0111 ||
+     combined == 0b1110 ||
+     combined == 0b1000) {
+    counter--;
+  }
+
+  previous = current;
+}
+
+void loop(){ 
+  bool buttonValue = digitalRead(pinButton);
+  if(buttonValue != previousButtonValue){
+    if(buttonValue) {
+      SurfaceDial.press();
+    } else {
+      SurfaceDial.release();
+    }    
+    previousButtonValue = buttonValue;
+  }
+
+  if(counter >= 4) {
+    SurfaceDial.rotate(10);
+    counter -= 4;
+  } else if(counter <= -4) {
+    SurfaceDial.rotate(-10);
+    counter += 4;
+  } 
+}