Okie from LeafLabs got down with some experimental signal processing using Leaf’s speedy Maple board and a custom shield -
Real-time audio processing is an example of an application where Maple really shines in comparison to Arduino. Maple has 12-bit ADCs with sample rates up to 1MSPS and PWM fast enough to clear ~11.8 bits of resolution (log2(72MHz/20kHz)=11.8) at a frequency twice the Nyquist frequency of the upper end of the bandwidth of the human ear (20kHz). And there’s a lot of clock cycles to do all kinds of really awesome stuff to the signal (e.g. echo, distortion, octave, harmony, equalization, flange, phaser, fuzz, ring modulation, and complete new imagined effects)!
The EAGLE schematic/PCB files, code, audio samples, and further explanation can be harvested over on the LeafLabs blog.
The Maple’s STM32 chip seems to be begging for more audio exploration like this. I imagine a basic music synth would be relatively easy to implement in comparison to effects processing.
Hmmm … must find more time for hacking.
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