Play with tone function.

speaker/speaker.ino

@@ -0,0 +1,35 @@
+// example of tone.
+const int SWITCH = 0;
+const int SPEAKER = 9;
+
+const int scale[] = {261, 293, 329, 349, 392, 440, 493, 523};
+
+volatile boolean state = true;
+
+void play() {
+  for(int i = 0; i < 8; i++) {
+    if(state) {
+      break;
+    }
+    tone(SPEAKER, scale[i]);
+    delay(250);
+  }
+  noTone(SPEAKER);
+  delay(250);
+}
+
+void stop() {
+  noTone(SPEAKER);
+  state = !state;
+  delay(100);
+}
+
+void setup() {
+  Serial.begin(9600);
+  pinMode(SPEAKER, OUTPUT);
+  attachInterrupt(SWITCH, stop, RISING);
+}
+
+void loop() {
+  play();
+}