Add CesarSound code.

lib/Rotary/examples/Interrupt/Interrupt.ino

@@ -0,0 +1,37 @@
+/*
+    Rotary Encoder - Interrupt Example
+    
+    The circuit:
+    * encoder pin A to Arduino pin 2
+    * encoder pin B to Arduino pin 3
+    * encoder ground pin to ground (GND)
+*/
+
+#include <Rotary.h>
+
+Rotary r = Rotary(2, 3);
+
+void setup() {
+  Serial.begin(9600);
+  r.begin();
+  PCICR |= (1 << PCIE2);
+  PCMSK2 |= (1 << PCINT18) | (1 << PCINT19);
+  sei();
+}
+
+void loop() {
+
+}
+
+ISR(PCINT2_vect) {
+  unsigned char result = r.process();
+  if (result == DIR_NONE) {
+    // do nothing
+  }
+  else if (result == DIR_CW) {
+    Serial.println("ClockWise");
+  }
+  else if (result == DIR_CCW) {
+    Serial.println("CounterClockWise");
+  }
+}