int led = 13;
volatile int i = 0;
int sw = 2;
void setup() {
attachInterrupt(0, changeLED, FALLING);
pinMode(sw, INPUT_PULLUP);
pinMode(led, OUTPUT);
}
void changeLED() {
i = 1;
}
void loop() {
if (i == 1) {
digitalWrite(led, 1);
delay (500);
digitalWrite(led, 0);
delay(500);
i = 0;
}
}