which (small but powerfull) board for dsp ?

[PF.1]

Hello,

I want to DSP an audio signal to create guitar effect(s), and someone pointed me the Nucleo boards,

- are they the right choice for DSP ?

- if yes, which have a narrow/small footprint board (similar to teensy 3.6 or RPI zero)

the product selector is not really helping for that matter

thanks for the time you'll spend on this question

(https://www.st.com/en/evaluation-tools/stm32-nucleo-boards.html#products)

Phil

[S.Ma]

Small form factor won't bode well with a development/prototyping board.

Most of the time, discovery boards include audio companion chips and audio codecs with Jacks and mems microphones.

Audio is tricky especially for the synhroneous and clocks.

I would start with Disco for STM32F76x and check newer ones based on H7 (more powerful with what it implies): It has double type 64 bit HW support.

[PF.1]

I can do decent (+-190khz sampling rate) audio on a raspberry pi zero (using an MCP3002 ADC), but linux gets in the way

[PF.1]

"start with Disco for STM32F76x" how do you mean ? can't find anything in google

[TDK]

Pretty much any STM32 is capable enough for DSP.

I believe the nucleo32 boards have a smallest form factor out of the official boards. I expect one or more of them can do the job. This one has ADC and DAC which should be all you need:

https://www.st.com/en/evaluation-tools/nucleo-l432kc.html

[PF.1]

24 MHz crystal oscillator.... compared to 240Mhz(Teensy) ang 1Ghz (RPI zero) ... is it the fastest board ?

[TDK]

The fastest? No, but you wanted the smallest.
Don’t confuse oscillator speed with clock speed. Max clock speed is much higher.
Stm32 cant compete with rpi in terms of total compute speed. But the rpi cant compete with stm32 in terms of realtime response.

[andrewg]

get any one of the STM32F4* mcu based boards e.g. F405, F407, F429 etc runs at 168 mhz and those has the ART accelerator (on chip cache), the psuedo whetstone single precision Mflops runs into numbers in the range of hundreds (may be like 200 Mflops) that used to be the speeds of the old Intel P4

https://www.stm32duino.com/viewtopic.php?t=27

pseudo because no one has proven if those large Mflops numbers are clever compiler optimizations which simply skip all the benchmark calculations.

but they are pretty fast

https://www.youtube.com/watch?v=0ETyFmAMFjY&t=20s

if that is still deemed not 'fast' enough for your applications, you can always get the F7* etc

if you want tiny, not just small, micropython, adafruit and olimex has the answers

micropython

https://store.micropython.org/product/PYBv1.1H

https://store.micropython.org/product/PYBD-SF2-W4F2

adafruit

https://www.adafruit.com/product/4382

olimex

https://www.olimex.com/Products/ARM/ST/STM32-H405/

then there are still the nucleos

do be wary that for the *tiny* boards, some pins may not be accessible as conventional 0.1" (2.54mm) pins or simply not accessible. check the specs

[Tesla DeLorean]

https://community.st.com/s/question/0D50X00009XkgXw/vccgnd-stm32f407vet6-mini-board

[PF.1]

"Don’t confuse oscillator speed with clock speed" ok, let's say that there are internal clock dividers and stuffs, how do I figure the frequency ?

also teensy 3.6 was deceiving cos the ADC has a 50% SNR, are the ADC on these boards less noisy ? any idea ?