Designing Sound in SuperCollider/DTMF
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26: DTMF dialling tones
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// This data structure (like a "hashtable" or "associative array" in other languages)
// maps from a phone key to a pair of frequencies in Hz.
// We can push these frequencies to a synth.
~tbl = IdentityDictionary[
$1 -> [[697, 1209]],
$2 -> [[770, 1209]],
$3 -> [[852, 1209]],
$4 -> [[697, 1336]],
$5 -> [[770, 1336]],
$6 -> [[852, 1336]],
$7 -> [[697, 1477]],
$8 -> [[770, 1477]],
$9 -> [[852, 1477]],
$* -> [[697, 1633]],
$0 -> [[770, 1633]],
$# -> [[852, 1633]],
$A -> [[941, 1209]],
$B -> [[941, 1336]],
$C -> [[941, 1477]],
$D -> [[941, 1633]]
];
// Here we define a SynthDef which plays a single "number" at a time.
// Note that our strategy here is a bit different from the PD code in the book:
// there, a single pair of sine-wave oscillators was re-used for each number,
// whereas here, we create (and later free) an individual synth for each number.
SynthDef(\dtmf, {|freq=#[770, 1633], out=0, amp=0.2, gate=1|
var son, env;
son = SinOsc.ar(freq, 0, amp).sum;
env = EnvGen.ar(Env.asr(0.001, 1, 0.001), gate, doneAction: 2);
Out.ar(out, Pan2.ar(son * env * amp));
}).add;
)
// Check that it works:
x = Synth(\dtmf) // create
x.set(\gate, 0) // free
(
// This pattern generates a random "phone number" and dials it
Pbind(
\instrument, \dtmf,
\dur, 0.2, // or for more "human" timing, try Pwhite(0.2, 0.5, inf)
\sustain, 0.15,
\amp, 0.3,
\freq, Prand(~tbl.asArray, 13)
).play;
)
(
// You could even dial a specific number:
Pbind(
\instrument, \dtmf,
\dur, 0.2, // or for more "human" timing, try Pwhite(0.2, 0.5, inf)
\sustain, 0.15,
\amp, 0.3,
\freq, Pseq("012827743866".collectAs({|digit| ~tbl[digit] }, Array))
).play;
)