2020-07-02 07:05 AM
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
2020-07-04 08:25 AM
One of the benefits of doing it yourself is you can use whatever sounds ok to you. I use 26k throughout because that's the fastest i could get the visible spectrum photodiodes i use with pwm. Sounds fine to my old ears. One thing to consider, however, is the dac sin(x)/x error which in practical terms really means that your max output frequency is closer to 1/3 nyquist.
2020-07-04 09:11 AM
ok
2020-07-05 02:48 AM
".... to add an external ram for reverbs/delays" - I have implemented reverb that sounds quite nice within the ram of the micro (<64k) - if you use reverb based on all-pass filters you don't need as much ram as you may think. Search for the application note "How to Create Delay-based Audio Effects on the TMS...". With some STM32L4(+) micros having up to 320Kb of ram - that's plenty for all my effects.
2020-07-05 05:52 AM
what if I have some ideas I want to implement ? I just want to interface a ram module, even just for the sake of doing it :)
what's the point of building a board if you can't make it the way you want
2020-07-05 12:13 PM
For audio development purposes STM32F769I-DISC1 (or ...-DISCO with LCD) is very nice. It has onboard 16 MB SDRAM, decent WM8994 audio codec with line in/out + speaker outputs and even coaxial SPDIF in/out.
Talking about internal ADC and DAC... 12-bit PCM audio has a theoretical dynamic range of 12-bit * 6 dB = 72 dB. That is enough for voice applications, but not for serious full range audio purposes.
2020-07-07 05:05 AM
i've one of these, i liked it a lot
https://www.st.com/en/evaluation-tools/32f429idiscovery.html
check out the F7* discovery offerings as well, i've not review their specs, the f7* discoveries tend to feel pricey but that they tend to bundle premium peripherals such as a larger lcd on board dram etc
e.g.
https://www.st.com/en/evaluation-tools/32f746gdiscovery.html