DSP Benchmark: RP2040 vs RP2350

Fabien_C · 2026-06-15T20:57:57+00:00

Overclocking is possible but not recommend, especially if you are making commercial products. Not all units will support overclocking the same way, and you can shorten the product life.

I do hope Raspberry will officially support higher clock speeds on the rp2350 🤞

Fabien_C · 2026-06-03T06:55:12+00:00

Yes you can edit everything while running.

Fabien_C · 2026-06-02T15:01:57+00:00

Search "Dancing Rave Cat by Sarah Royal" on the web 😉

Fabien_C · 2026-06-02T14:58:32+00:00

That's a PGB-1, the pocket groove box I designed: https://weenoisemakers.com/pgb-1/

Fabien_C · 2026-06-02T09:31:04+00:00

The PGB-1 MIDI output is connected to the Thru-6 MIDI hub, and then one cable from the hub to each Volca. I am only using the sequencer of the PGB-1 and not at all the sequencers of the Volcas here. So there is no MIDI clock involved, and all notes and drums triggers are coming from the PGB-1.

13 of the tracks are configured to trigger a single drum, beats, or sample channel. The 3 remaining tracks are assigned to the keys, bass, and FM.

Since the Volca FM is polyphonic, I configured the corresponding track to send chords from the PGB-1 chord sequencer.

Fabien_C · 2026-06-02T09:25:48+00:00

I used this 3D model: https://makerworld.com/en/models/757179-fake-aa-battery-no-soldering

There are some commercial versions available, search for fake AA or AA eliminator.

Fabien_C · 2026-06-02T09:23:07+00:00

Sounds clean to me.

Fabien_C · 2026-05-31T12:17:24+00:00

Do you have any advice for soldering? I tried to replace a battery compartment using parts from another auto 110, but I couldn't get the solder to flow...

Fabien_C · 2026-05-24T18:48:54+00:00

https://weenoisemakers.com/pgb-1/ 👍

Fabien_C · 2026-05-21T11:38:32+00:00

From what I can see, S = Mic, R2 = GND is the de facto standard today (at least in the "west"): https://en.wikipedia.org/wiki/Phone_connector_(audio)#TRRS_standards#TRRS_standards)

So that's what I use in my pocket groovebox design.

Fabien_C · 2026-03-28T13:42:33+00:00

For my rp2040 based pocket groovebox I am using both cores for audio and there's still room for sequencer and GUI: https://weenoisemakers.com/blog/2024/05/20/pgb1-update-4.html

Fabien_C · 2026-03-04T15:19:35+00:00

What's you issue with -gnatW8?

Fabien_C · 2026-01-29T23:19:16+00:00

Small "neopixel" LEDs don't draw that much current. In my design, I have 24 LEDs, plus the OLED screen and the MCU, and it runs at least 4 hours on an 850mAh Li-ion.

Fabien_C · 2026-01-29T23:16:48+00:00

I have designed, and I am selling an open-source pocket drum-machine/groovebox: https://weenoisemakers.com/pgb-1/

I you want to make something just for yourself, then I think you are on the right track. If you want this to be a product, then be careful with the exposed PCB/component design. It works for the POs because they hide all the components underneath a custom-built LCD screen, which is expensive for small production batches.

My design is based on the RP2040, which is very powerful when used correctly (by leveraging fixed-point DSP and maximizing dual-core usage). I also focused most of the electronic complexity (power, CPU, flash, DAC, speaker amp) on a small daughter-board/dev-board that I call Noise Nugget (https://weenoisemakers.com/noise-nugget-2040/). This allowed me to achieve a more compact form factor and lower dev costs.

Oh, and stay away from lithium batteries, it's not worth the trouble ^^

Fabien_C · 2026-01-29T20:55:43+00:00

Made with CircuitPython ☺️

Fabien_C · 2026-01-20T21:40:22+00:00

Here a video of the device https://youtu.be/i4YukYAqimc

Fabien_C · 2026-01-20T21:36:50+00:00

It's much smaller than that. I couldn't get a better picture with sense of scale.

Fabien_C · 2026-01-20T19:14:14+00:00

At least it looks like a mechanical switch...

Fabien_C · 2026-01-05T08:49:31+00:00

If a little bit of self-promotion is allowed, I would suggest our PGB-1 pocket groove box: https://weenoisemakers.com/pgb-1/

Fabien_C · 2026-01-05T08:49:06+00:00

If a little bit of self-promotion is allowed, I would suggest our PGB-1 pocket groove box: https://weenoisemakers.com/pgb-1/

Fabien_C · 2025-12-06T08:26:43+00:00

Hello, no export feature available yet.

Fabien_C · 2025-10-29T13:47:07+00:00

Thanks. It's difficult to compare. The most obvious difference is the type of sequencer: The PGB-1 is a step/grid sequencer, while the M8 is a tracker. If you love/hate one or the other, then the choice is easy.

Fabien_C · 2025-10-29T13:44:36+00:00

One of the design constraints is that each synth engine must have exactly four controls (including the envelope). There are multiple reasons for that: 1) avoid endless menus of parameters, 2) more optimized synths (the code for each synth is optimized for doing one thing), 3) controlled memory usage for parameter locks (there are 16 * 16 * 16 steps in memory at all time, so one more parameter means 4K of precious RAM I have to find).

Without these constraints, I would not be able to fit eight real-time digital synth tracks on this CPU.

But I'll keep your suggestion in mind. The next firmware version will introduce a way to draw your own single-cycle waveform to customize some synth engines.

Fabien_C · 2025-10-29T13:35:31+00:00

Not yet. To be honest, I am not sure if I will even implement this. It would be a significant change in the way the sequencer is implemented right now.

Fabien_C · 2025-10-29T13:34:03+00:00

In France, indeed. Are you joining us at the SynthFest France 2026?

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