[sdiy] In praise of the ATM STM32F303

[Olivier Gillet]

> I didn’t know this, it sounds interesting! Does it mean that you could get away with not band-limiting your oscillator’s waveforms, and always "snap" their frequency to a multiple/divider of the DAC clock? And generate the DAC clock from one of the high-res timers on the STM?

If you're only interested in pure digital generation, you don't even
have to use this feature - you can also directly alter the frequency
of the timer that clocks the DAC updates. This works well for simple
monophonic waveform generation. I considered using it for a while for
Braids, before realizing that half of the algorithms I wanted to
implement required two oscillators, or that the variable frequency
complicated the calculations (for example for the models in which
there are filters).

This variable-rate clocking approach is not very suitable for
polyphony - if you want to play two distinct frequencies, you'll need
two timers and two DACs...

Colin's suggestion is about using an external clock source, such as a
VCO, to clock the reads.