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

[RMcCa]

It's up to you whether to use somebody else's code or write your own. I have implemented many different sound generation/signal processing algorithms using bare-metal f730s. For example, a single f730 running at 216Mhz with a 26Khz sample rate can calculate 2 8 channel vocoders in real-time. That is 4x8 4 pole biquad filters and 2×8 envelope followers and multipliers. No problem. ​

[RMcCa]

Also, wavetable synthesis is mearly another way of talking about DDS. It's not complicated at all and can be implemented with just a few lines code. Read about FM operators. Chowdry was able to make music with punch cards and a PDP-8​ altho not in real-time. Now you can do it real-time with a $5 chip.

[andrewg]

one of those ways of overcoming those memory challenges is to get a board with on board sdram, the f4* , f7* has pretty good support for them, some boards has on board 8 MB sd ram chips. those would make memory intensive tasks significantly easier. you can do malloc etc. malloc on small sram systems e.g. 64k, 128k tend to be challenging and in 20k sram is 'wishful thinking' at best, the stack and heap would have used most of that.

[PF.1]

the teensy 3.6 has a 12 bits resolution, but apparently it does not keep them from bringing tons of noise, making these DAC barely usable, guess I'll have to try a board to figure it out

[PF.1]

wow dude... that's the answer I was looking for

you mean the NUCLEO-L412KB ?

https://www.digikey.be/product-detail/en/stmicro/NUCLEO-L412KB/497-18239-ND/9656229?utm_adgroup=Development%20Boards%2C%20Kits%2C%20Programmers&utm_source=google&utm_medium=cpc&utm_campaign=Shopping_Supplier_STMicroelectronics&utm_term=&productid=9656229&gclid=Cj0KCQjw0YD4BRD2ARIsAHwmKVnwqvXyYKkFQ3z...

[PF.1]

lol, I am currently checking how to bare metal the sh#t out of an RPI zero in C/ASM

• you're talking about the STM32F730I8 ? I usualy design my own boards, I can solder small packages, but this one is something a machine should put together (PcbWay or something)...do you have a tutorial I could learn from ? always wanted to make aboard with an arm processor

• there are 4 chips, what's the main difference ? STM32F730I8, STM32F730R8, STM32F730V8, STM32F730Z8 ?

• is there a way to add an external ram for reverbs/delays ?

[PF.1]

I dont mind bare metal, indeed the isue is to have something that has memory, speed and decent IO's

another challenge is to find a board(narrow & small in my case) and if going bare metal, finding math libraries

going baremetal on a RPI means finding USB libraries too

[PF.1]

so one can't do 44khz ?

[PF.1]

nice... any ready made board that does that ?

[gregstm]

the slower the sampling frequency you can get away with, the more processing time you have (and the more power you can save). I use 16KHz sampling rate. The highest note on the guitar is 1318Hz (E6 - 24th fret). Sounds ok to me - but then again, my hearing is probably not what it used to be....