/* Arduino Starter Kit example Project 15 - Hacking Buttons This sketch is written to accompany Project 15 in the Arduino Starter Kit Parts required: batery powered component 220 ohm resistor 4N35 optocoupler Created 18 September 2012 by Scott Fitzgerald http://arduino.cc/starterKit This example code is part of the public domain */ const int optoPin = 2; // the pin the optocoupler is connected to void setup() { // make the pin with the optocoupler an output pinMode(optoPin, OUTPUT); } void loop() { digitalWrite(optoPin, HIGH); // pull pin 2 HIGH, activating the optocoupler delay(15); // give the optocoupler a moment to activate digitalWrite(optoPin, LOW); // pull pin 2 low until you're ready to activate again delay(21000); // wait for 21 seconds }