const int spk = 7;

const int onOff = 2;

volatile int toggle;

boolean output;

int dot = 250; //dot time 250 ms;

int dash = 750; //dash is 3 dot times

int space = 750; //space is 3 dot times

int newWord = 1750; //space between words is 7 dot times

void setup() {

pinMode (spk, OUTPUT);

pinMode (onOff, INPUT_PULLUP);

attachInterrupt(0, resetISR, LOW); //hardware interrupt on pin 2

}

void loop() {

output = digitalRead (onOff);

delay(150);//debounce

if (output == 0 && toggle == 0) {

toggle = 1;

}

while (toggle > 0) {

tone(spk, 2000, dot); //letter S

delay(dot + dot);

tone(spk, 2000, dot);

delay(dot + dot);

tone(spk, 2000, dot);

delay(dot + space);

tone(spk, 2000, dash); //letter O

delay(dash + dot);

tone(spk, 2000, dash);

delay(dash + dot);

tone(spk, 2000, dash);

delay(dash + space);

tone(spk, 2000, dot); //letter S

delay(dot + dot);

tone(spk, 2000, dot);

delay(dot + dot);

tone(spk, 2000, dot);

delay(newWord);

}

}

void resetISR() { //reset function, shuts off xmitter

if (toggle == 1) {

toggle = 0;

}

}