What does it take to turn a Raspberry Pi Pico 2 into a real-time, AI-powered USB microphone?
Project 17 in my book, Embedded AI, brings together machine learning, digital signal processing, and embedded systems to tackle audio noise suppression.
This video shows the journey from microphone to PC:
- A T3902 PDM MEMS microphone captures audio.
- PIO and DMA acquire the bitstream, ready for conversion into PCM samples.
- Core 1 runs RNNoise to suppress noise.
- Core 0 streams the denoised audio over USB using TinyUSB.
- An IPS LCD displays the output spectrogram, while the onboard LED changes brightness with the model’s confidence that voice is present.
Making it all work means coordinating two cores, moving data through ring buffers, and keeping the audio flowing in real time.