DSPi Brings Multichannel Audio DSP to Raspberry Pi Pico and Pico 2
Reading lead
Weeb Labs has published DSPi, GPL v3 firmware that configures the Raspberry Pi Pico (RP2040) and Pico 2 (RP2350) as USB sound cards with onboard digital signal processing. Listed functions include room correction, active crossovers, parametric equalization, time alignment, loudness compensation and headphone crossfeed. Both boards run at a fixed 307.2 MHz clock, selected to keep PIO dividers integer at 44.1, 48 and 96 kHz; the RP2040 requires a small voltage increase. The article says the RP2350’s hardware floating-point unit gives it capacity for 11 channels and 9 outputs, compared with 7 channels and 5 outputs on RP2040. Output slots can switch between S/PDIF and I2S at runtime, with both formats usable on one device. Pin assignments can be changed without reflashing and saved in one of ten presets. A Core 1 delta-sigma modulator provides a PDM subwoofer output through a simple RC low-pass filter. The firmware builds with the standard Pico C/C++ toolchain; the article provides no independent performance measurements.
Article body
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Weeb Labs has published DSPi on GitHub, a firmware that turns a Raspberry Pi Pico or Pico 2 into a USB sound card with an onboard DSP engine. It handles room correction, active crossovers, parametric EQ, time alignment, loudness compensation, and headphone crossfeed.
Both chips run at a fixed 307.2 MHz system clock, which keeps the PIO dividers integer at 44.1, 48 and 96 kHz. The RP2040 needs a small voltage bump to get there. The RP2350 has more headroom thanks to its hardware floating point unit, so it supports 11 channels and 9 outputs against the RP2040’s 7 and 5.
Each output slot can be switched between S/PDIF and I2S at runtime, and a single device can mix the two. Output pins can be reassigned without reflashing, and assignments are stored in flash with one of 10 presets. A delta-sigma modulator on Core 1 drives a PDM subwoofer output through a simple RC low-pass filter.
The firmware is GPL v3 and builds with the standard Pico C/C++ toolchain.
See more on GitHub.
Source: Anne Barela ·Adafruit Blog · 2026-10-08T16:40:25.000Z · Read the original article
Why read this
This is a concrete open-source firmware release with configurable multichannel DSP and interface options; the article gives feature and channel counts but no independent performance testing.
AI score 57 · View scoring rationale
Two-model scores assess source reading value, not factual accuracy. Check this editorial article against the original.
- gpt-6-luna-2026-09-22 · 57
This is a concrete open-source firmware release with configurable multichannel DSP and interface options; the article gives feature and channel counts but no independent performance testing.
- deepseek-v4-1-flash-260910 · 58
Concrete open-source firmware release with specific specs for both RP2040 and RP2350, including channel counts, clocking, runtime I2S/S/PDIF switching, and PDM subwoofer output; evidence is project documentation without independent testing.
Analyzed: 2026.10.09 03:24 UTC
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