Added envelope generator

basics/envelope-generator/envelope-generator.ino

@@ -0,0 +1,47 @@
+/*
+ * 
+ * Envelope Generator (ADSR)
+ * 
+ * A3 = trigger (sync) in
+ * 
+ */
+
+int pwmPin = 11; //define output pin, Meergranen output pin is 11
+bool triggered; // logic: trigered, yes or no
+
+void setup() {
+  pinMode(pwmPin, OUTPUT); //set pin as output
+  Serial.begin(9600); // debugging (see if trigger is registered)
+}
+
+void loop() { // run forever
+  int input3 = digitalRead(A3); // read analog pin 3, detect triggers
+
+  if(input3 && !triggered) {
+
+//ATTACK
+     for(int value = 0; value<=255; value++){ // cycle through 255 values, start at 0. 8 bit output == 255 values
+         analogWrite(pwmPin, value); // analogWrite simulates smooth sinewave using complex pwm duty cycles
+//DELAY
+         delay(1);
+      }
+      
+ //SUSTAIN       
+    for(int value = 255; value>=0; value--){ // cycle through 255 values, start at 0. 8 bit output == 255 values
+        analogWrite(pwmPin, value); // analogWrite simulates smooth sinewave using complex pwm duty cycles
+        delay(2);
+      }
+
+//RELEASE
+    delay(20);
+
+        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;
+     
+    }
+
+    
+}