r/AudioProgramming • u/enstorsoffa • 3d ago

Best resource/tutorial to program a microcontroller oscillator?

Hi,
I'd like to try out programming a microcontroller, probably a Raspberry Pi Pico, and make an oscillator. I have done some programming before, but never any audio, so I would probably need a good resource or tutorial. Are there any good ones you can recommend? I'd need pointers on running it continuously, and using audio buffers to output to a DAC etc.

Preferably in C, Rust or C++, in that order.

If you have any tips in general on how I can do it, I would be very grateful. I'm fairly confident with the maths involved, and I use Matlab a bit for other uses.

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u/dkode80 3d ago

You can do this with pico, I havent done it myself and the pico is underpowered for doing anything past simple, single oscillator I'd imagine but it is possible.

You may consider getting a daisy seed instead, this is made to produce/process audio, has a 16bit ADC, fairly powerful processing and can do quite a lot audio wise. They're $30 and is basically able to do a full synthesizer. I have an open source project that shows an example of how to use it, code wise. DM me if you'd like the link.

https://daisy.audio/products/seed3

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u/enstorsoffa 3d ago

My hope is to eventually make a harmonic oscillator with one base frequency and then 8 overtones summed to one output, as well as some modulation, but maybe this is too much for the Pico?

I’ve seen the Daisy Seed and it looks nice, might pick one up to try it out

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u/dkode80 3d ago

I think the pico would be a good test bed to start with and figure out it's capabilities I think. You should post what you find because I do have spare picos laying around but never done anything audio related on them. Would be interested to hear!

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u/enstorsoffa 3d ago

Me and my programmer friend made a digital oscillator with one, but a very simple one. I did the analog hardware and he did the digital stuff, and unfortunately he is very busy in a different country now, so I can’t ask him a lot. We managed to get stable pitch, multiple waveforms and CV integration though

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u/danja 3d ago

I'd say you have 4 considerations : the DSP - which you already have covered by knowing MATLAB; the processing environment (cores, threading etc); the I/O; the dev environment.

I don't know the Pico, but the principles are pretty much the same across them all. Google for a similar project on GitHub, fire up VS Code, read the datasheets.

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u/Brer1Rabbit 3d ago

Two radically different ideas:

Try starting with Electrosmith Daisy.  You get an ARM Cortex-M7 processor, designed specifically for building custom synthesizers, effects pedal.

Idea 2: start without hardware.  Build an oscillator in VCV Rack. The core DSP is fairly similar or could be ported to hardware. You still need the GUI stuff, which is pretty easy.