On 09/04/2012, robert bristow-johnson <r...@audioimagination.com> wrote: > > i hadn't heard of this dev board before. at > http://www.st.com/internet/evalboard/product/252419.jsp it says that the > single unit prices is US$14.9 . is that right? that's nearly free.
They were giving them out free in the US for a while, I believe. > regarding wavetable indexing, somewhere Julian must be converting float > to int, no? i am still convinced that the correct way to implement it > is with pure integer arithmetic. to implement a good NCO, you need a > lot of bits in the phase accumulator. i might think that 32 would be > enough. And therein, I suspect, lies the problem; the STM32F4 is a Cortex M4F implementation, which means it has a single-precision FPU onboard - ie only 24 bits of precision. I have a feeling that what's in evidence here is just rounding error. Especially given that the problem only manifests when the difference between the phase increment and a multiple of the sample rate is really small. -- dupswapdrop -- the music-dsp mailing list and website: subscription info, FAQ, source code archive, list archive, book reviews, dsp links http://music.columbia.edu/cmc/music-dsp http://music.columbia.edu/mailman/listinfo/music-dsp
