Propeller Demo Board for Audio Synthesis?

Rex Rhino

Hello!

I am just wondering how effective would the propellor demo board be for audio synthesis? Specificly, I would like to generate several drum sounds, as well as sequence the playback of the samples using P0-P7. Is a drum machine a reasonable application for the propeller demo board?

Thanks!

cgracey

You can do this. It will be necessary to program the synthesis core in assembly language, though, to get the sample throughput.
You can output to any pin(s), but the Demo Board does have a nice stereo headphone amp connected to pins 10 and 11 which can be delta-modulated.

Rex Rhino said...
Hello!

I am just wondering how effective would the propellor demo board be for audio synthesis? Specificly, I would like to generate several drum sounds, as well as sequence the playback of the samples using P0-P7. Is a drum machine a reasonable application for the propeller demo board?

Thanks!

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Chip Gracey
Parallax, Inc.

Paul Baker

What type of synthesis are you looking for; additive, subtractive, FM, PCM?

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Rex Rhino

Paul: I would be looking to do FM and subtractive synthesis, and PCM if possible.

Paul Baker

I think all should be possible, 20 MIPS should be sufficient for subtractive and FM, and the 1.25 MAPS (million accesses per second) of the hub memory is sufficient for PCM. You could even use the sine table lookup to do probably a 9 or more harmonic additive system (the harmond was a 3 harmonic additive). For the true synthesis systems (such as subtractive), youd use a noise generator as the input for precussion instruments, this can be done on the fly or using a small table in the cog's memory (human ears dont really pickup the diffence between table noise and "true" noise).

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1+1=10