Added trigger detection example

basics/trigger-detect/trigger-detect.ino

@@ -0,0 +1,36 @@
+/*
+ * 
+ * Trigger Detect
+ * 
+ * 
+ * Detecting triggers is essential to interact with other modules, for example to generate short bursts of sounds
+ * Try the output of simple-lfo.ino with this patch and open the serial monitor to see what happens!
+ * 
+ * A3 = Trigger in
+ * 
+ */
+
+
+bool triggered; // logic: trigered, yes or no
+
+
+void setup() {
+  Serial.begin(9600); // debugging (see if trigger is registered)
+}
+
+void loop() {
+  
+  int input3 = digitalRead(A3); // read analog pin 3
+  
+  //  trigger 
+  if(input3 && !triggered) { //if there is a reading on input3 and the bool condition triggered is not true do
+      Serial.println("I hear a trigger!");
+      // DO SOMETHING ON TRIGGER HERE
+      triggered = true;
+    }
+    else if(!input3 && triggered) { //if there is no reading on input3 and condition triggered is true (aka sound is playing), set triggered to false, aka stop playing 
+      // STOP WHEN NO TRIGGER IS PRESENT (or do something else ;)
+      triggered = false;
+    }
+
+}