How to create sound data

Note that emitting 0x0000 and 0xffff will emit a square wave. Unless you have a low-pass filter, your output will contain large amounts of energy in overtone frequencies, besides the base frequency.

A problem when handling PCM data is to make sure that you don't have a signed/unsigned problem.

The sound recorder is one way, but best when you want to capture speech messages or music. For DTMF or similar, it is normally easier to just sum the sine waves in a C program, and let the program emit the data in text form for direct inclusion in the source code. Wieh you compute the frequencies matematically, it will also be trivial to create a sound clip that has the perfect number of samples for looped playback, i.e. where the clip has n samples and the n+1 sample should have been identical to the first sample.

Note that emitting 0x0000 and 0xffff will emit a square wave. Unless you have a low-pass filter, your output will contain large amounts of energy in overtone frequencies, besides the base frequency.

A problem when handling PCM data is to make sure that you don't have a signed/unsigned problem.

The sound recorder is one way, but best when you want to capture speech messages or music. For DTMF or similar, it is normally easier to just sum the sine waves in a C program, and let the program emit the data in text form for direct inclusion in the source code. Wieh you compute the frequencies matematically, it will also be trivial to create a sound clip that has the perfect number of samples for looped playback, i.e. where the clip has n samples and the n+1 sample should have been identical to the first sample.