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A Morse Code generator in Java Script
function MorseNode(ac, rate) {
// ac is an audio context.
this._oscillator = ac.createOscillator();
this._gain = ac.createGain();
this._gain.gain.value = 0;
this._oscillator.frequency.value = 750;
this._oscillator.connect(this._gain);
if(rate == undefined)
rate = 20;
this._dot = 1.2 / rate; // formula from Wikipedia.
this._oscillator.start(0);
}
MorseNode.prototype.connect = function(target) {
return this._gain.connect(target);
}
MorseNode.prototype.MORSE = {
"A": ".-",
"B": "-...",
"C": "-.-.",
"D": "-..",
"E": ".",
"F": "..-.",
"G": "--.",
"H": "....",
"I": "..",
"J": ".---",
"K": "-.-",
"L": ".-..",
"M": "--",
"N": "-.",
"O": "---",
"P": ".--.",
"Q": "--.-",
"R": ".-.",
"S": "...",
"T": "-",
"U": "..-",
"W": ".--",
"X": "-..-",
"Y": "-.--",
"Z": "--..",
"1": ".----",
"2": "..---",
"3": "...--",
"4": "....-",
"5": ".....",
"6": "-....",
"7": "--...",
"8": "---..",
"9": "----.",
"0": "-----"
};
MorseNode.prototype.playChar = function(t, c) {
for(var i = 0; i < c.length; i++) {
switch(c[i]) {
case '.':
this._gain.gain.setValueAtTime(1.0, t);
t += this._dot;
this._gain.gain.setValueAtTime(0.0, t);
break;
case '-':
this._gain.gain.setValueAtTime(1.0, t);
t += 3 * this._dot;
this._gain.gain.setValueAtTime(0.0, t);
break;
}
t += this._dot;
}
return t;
}
MorseNode.prototype.playString = function(t, w) {
w = w.toUpperCase();
for(var i = 0; i < w.length; i++) {
if(w[i] == ' ') {
t += 3 * this._dot; // 3 dots from before, three here, and
// 1 from the ending letter before.
}
else if(this.MORSE[w[i]] != undefined) {
t = this.playChar(t, this.MORSE[w[i]]);
t += 2 * this._dot;
}
}
return t;
}

tdeck commented Dec 24, 2014

You're missing a "V": "...-" :).

I'd like to extend this a bit and make it into an npm package with an MIT license. Any objections?

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