Add another .ino sample for more precision

samples/Arduino/octave_changer

@@ -0,0 +1,55 @@
+const int buttons[4] = {2,3,4,5};
+const int octaves[2] = {6,7};
+
+void setup() {                
+  // initialize the digital pin as an output.
+  // Pin 13 has an LED connected on most Arduino boards:
+
+  pinMode(13,OUTPUT);
+
+ for(int i =0;i<sizeof(buttons)/sizeof(int);i++){
+   pinMode(buttons[i],INPUT );
+ }
+ 
+ for(int i =0;i<sizeof(octaves)/sizeof(int);i++){
+   pinMode(octaves[i],INPUT );
+ }
+ 
+  Serial.begin(9600);
+}
+
+
+void loop() {
+  delay(1);              // wait
+  int output = -1;
+  
+ // Serial.print(digitalRead(buttons[0]));
+  
+ for(int i =0;i<sizeof(buttons)/sizeof(int);i++){
+   if(digitalRead(buttons[i])==LOW
+   ){
+     if(output<=0){
+       output=1;
+     }
+     output+=i+1;
+   }
+ }
+ 
+ for(int i =0;i<sizeof(octaves)/sizeof(int);i++){
+    if(output<=0){
+       break;
+     }
+   if(digitalRead(octaves[i])==LOW
+   ){
+     output*=7*(i==1 ? -1 : 1);
+   }
+ }
+  if(output>=0){
+  Serial.print(output);
+  Serial.println(";");
+  digitalWrite(13,HIGH);
+  }else{
+  digitalWrite(13,LOW);
+  }
+  
+}