Electronics > Projects, Designs, and Technical Stuff
Getting started with DSP for audio effects
<< < (3/4) > >>
janekm:
Have a look at the CMSIS DSP libraries which can be used with ARM-based microcontrollers from all the major vendors. Plenty of dev boards around and the library is quite easy to use (by DSP standards).
On most chips it'll be grunty enough for simple guitar effects.
diyaudio:
Most of your DSP effort, when working either with a Processor or MCU  is not even DSP related, 70% of the work is actually digital audio timing and configuration, i.e getting the platform to efficiently take audio samples and move it (fast) from some audio source to some destination, Example: An I2S (source) to an audio codec (destination), this is where all the effort lies, its takes some domain knowledge (familiarity) to setup a system just to perform what is known as a "talk through" sample, the DSP is just code that can be ported from Matlab to some target (or a library like cmsis dsp).
Lucky for you, you dealing with a single channel audio effect, significant effort applies.

One of the best learning eval boards for this and cheap is a STM32F4 discovery it has everything you need, and the sample code actually works, plus there are lots of resources on the internet.   

ehughes:
This will help getting started:   (the dev board use for this is no longer in production but it is just a cortex M4)

https://community.nxp.com/docs/DOC-100149

https://circuitmaker.com/Projects/Details/Eli-Hughes/MonkeyJam

As diyaudio stated,  most of the work is house keeping.     Getting your samples in and out efficiently, etc.       Most actual code for effects use per-sample techniques.     i.e.   bring in a sample, do something with it and send it out.      There are a small number of "block" based algorithms (gather 256 samples, processing them and then queue for output) but for real time this is generally avoided as the latency stacks up through your signal chain.

The Analog devices Sigma DSP's will do most of what you want:

https://www.analog.com/en/design-center/processors-and-dsp/evaluation-and-development-software/ss_sigst_02.html

 https://www.analog.com/en/products/processors-dsp/dsp/sigmadsp-audio-processors.html

If you want a quick environment to try things without investing a lot of time,  SigmaStudio is a good fit.

Some open source Sigma studio Hardware:

http://www.freedsp.cc/




diyaudio:

--- Quote from: ehughes on November 16, 2018, 03:29:33 pm ---This will help getting started:   (the dev board use for this is no longer in production but it is just a cortex M4)

https://community.nxp.com/docs/DOC-100149

https://circuitmaker.com/Projects/Details/Eli-Hughes/MonkeyJam

As diyaudio stated,  most of the work is house keeping.     Getting your samples in and out efficiently, etc.       Most actual code for effects use per-sample techniques.     i.e.   bring in a sample, do something with it and send it out.      There are a small number of "block" based algorithms (gather 256 samples, processing them and then queue for output) but for real time this is generally avoided as the latency stacks up through your signal chain.

The Analog devices Sigma DSP's will do most of what you want:

https://www.analog.com/en/design-center/processors-and-dsp/evaluation-and-development-software/ss_sigst_02.html

 https://www.analog.com/en/products/processors-dsp/dsp/sigmadsp-audio-processors.html

If you want a quick environment to try things without investing a lot of time,  SigmaStudio is a good fit.

Some open source Sigma studio Hardware:

http://www.freedsp.cc/

--- End quote ---

Sigma studio is about DSP blocks, no code. I think he/she wants hands on DSP using code without helper blocks.
coppice:

--- Quote from: diyaudio on November 16, 2018, 04:07:11 pm ---Sigma studio is about DSP blocks, no code. I think he/she wants hands on DSP using code without helper blocks.

--- End quote ---
Sigma studio is a lot more restrictive than that. The Sigma devices only support a narrow range of DSP functions. They should suit the OP's filtering needs, but won't get very far with the distortion effects they showed interest in.
Navigation
Message Index
Next page
Previous page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod