added snare with external trigger

basics/snare-ext-trigger/snare-ext-trigger.ino

@@ -0,0 +1,49 @@
+/*
+ * 
+ * Snare - External trigger
+ * 
+ */
+long randNumber; //variable to store random number
+int pwmPin = 11; //define output pin, Meergranen output pin is 11
+bool triggered; // logic: trigered, yes or no
+
+void setup() {
+  // if analog input pin 5 is unconnected, random analog
+  // noise will cause the call to randomSeed() to generate
+  // different seed numbers each time the sketch runs.
+  // randomSeed() will then shuffle the random function.
+  randomSeed(analogRead(5));
+  Serial.begin(9600);
+  pinMode(pwmPin,OUTPUT); //set pwmPin to output mode (otherwise the built-in pulldown resistor sets it as input, aka you wont hear anything)
+}
+
+void loop() {
+
+  int input3 = digitalRead(A3); // read analog pin 3
+
+  if(input3 && !triggered) { //if there is a reading on input3 and the bool condition triggered is not true do
+
+
+  for(int i=0;i<25;i++){ 
+    randNumber = random(10, 100); //generate random number between 10 and 100
+    digitalWrite(pwmPin, LOW); //set output pin to LOW (0v)
+    delayMicroseconds(randNumber/10*(i/4)*(analogRead(A1)/10));//wait for randomNumber (10-100 Mircroseconds (0.00001-0.0001 seconds))
+    digitalWrite(pwmPin, HIGH); //set output pin to HIGH (5v)
+    delayMicroseconds(randNumber/10*(i/4)*(analogRead(A1)/10)); //wait for randomNumber (10-100 Mircroseconds (0.00001-0.0001 seconds))
+  }
+   for(int i=0;i<200;i++){ 
+    randNumber = random(10, 100); //generate random number between 10 and 100
+    digitalWrite(pwmPin, LOW); //set output pin to LOW (0v)
+    delayMicroseconds(randNumber);//wait for randomNumber (10-100 Mircroseconds (0.00001-0.0001 seconds))
+    digitalWrite(pwmPin, HIGH); //set output pin to HIGH (5v)
+    delayMicroseconds(randNumber); //wait for randomNumber (10-100 Mircroseconds (0.00001-0.0001 seconds))
+  }
+
+   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;
+    }
+
+}