more explaining

basics/simple-osc-explained/simple-osc-explained.ino

@@ -31,15 +31,31 @@ void setup() {
 
 void loop() {
 
-
-    digitalWrite( SPEAKER_PIN, LOW );
-    delayMicroseconds( analogRead(A2)*2 ); // wait 
-    digitalWrite( SPEAKER_PIN, HIGH );
-    delayMicroseconds( analogRead(A2)*2 ); // wait 
-
+    //in simple-osc.ino we use tone(outputpin, 1000); to make a 1000Hz tone
+    //1000Hz means 1000x on and off in one second.
+    //instead of using tone(), we can write out what happens:
+    //turn on a pin on and of on/off 1000x per second:
+
+    digitalWrite( SPEAKER_PIN, LOW ); //turn pin off
+    delayMicroseconds( 500 ); // wait 
+    digitalWrite( SPEAKER_PIN, HIGH );//tunr pin on
+    delayMicroseconds( 500 ); // wait 
+
+    //the wait period determains how long it takes to loop through the
+    //code, and thus how fast the code runs, and thus how fast
+    //the pin turns on and off and thus at what frequency this happens:
+    //we get an oscillation (on-off)!
+    //Maths:
+    //  for 1Hz, the pin goes on and off in one second. So the delay should be 0.5 second
+    //  for 1000Hz the pin goes on/off 1000x in 1 sec. So the delay should be 1000x smaller: 0.0005 seconds
+    //  wich is 500 micro seconds (dont confuse milliseconds with microseconds).
+
+    //To control the frequency with a knob we can use analogRead, uncomment the code below (and comment out the one above):
+
+//    digitalWrite( SPEAKER_PIN, LOW ); //turn pin off
+//    delayMicroseconds( analogRead(A2) ); // wait 
+//    digitalWrite( SPEAKER_PIN, HIGH );//tunr pin on
+//    delayMicroseconds( analogRead(A2) ); // wait 
+    
   
-
-  //note: delayMircoseconds wont pause your whole code like normal delay() would do
-  //so, the code inside the while loop is executed simultaniously with the code in the
-  //main loop. See usage in simple-poly-osc.ino
 }