int inPin = 2; // the number of the input pin int outPin = 13; // the number of the output pin int state = HIGH; // the current state of the output pin int reading; // the current reading from the input pin int previous = LOW; // the previous reading from the input pin // the follow variables are long's because the time, measured in miliseconds, // will quickly become a bigger number than can be stored in an int. long time = 0; // the last time the output pin was toggled long debounce = 200; // the debounce time, increase if the output flickers void setup() { pinMode(inPin, INPUT); pinMode(outPin, OUTPUT); } void loop() { reading = digitalRead(inPin); // if the input just went from LOW and HIGH and we've waited long enough // to ignore any noise on the circuit, toggle the output pin and remember // the time if (reading == HIGH && previous == LOW && millis() - time > debounce) { if (state == HIGH) state = LOW; else state = HIGH; time = millis(); } digitalWrite(outPin, state); previous = reading; }