Bertrik Sikken: Created page with "== The plan == The plan is to sample audio using a microphone, build a waveform display visualisation, send it over pixelflut to a display To sample audio, I plan to use an E..."

2019-06-10T12:29:39Z

Created page with "== The plan == The plan is to sample audio using a microphone, build a waveform display visualisation, send it over pixelflut to a display To sample audio, I plan to use an E..."

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== The plan ==
The plan is to sample audio using a microphone, build a waveform display visualisation, send it over pixelflut to a display

To sample audio, I plan to use an ESP32 and an I2S digital microphone.
I already have those available

The visualisation shows the raw waveform.
In order to get a more-or-less stable picture, each new frame is chosen such that it resembles the previous frame.
This is done with a cross-correlation. An FFT can be used for this.
Suppose the display is 128 pixels wide, a piece of audio is sampled twice as wide (256 samples) and we find the 128-sample wide section that most resembles the existing waveform.

Pixelflut is a protocol to send image data to a display, you can send one pixel per message in a kind of ASCII format.

The display is a 128x16 RGB display, build out of LED panels.

PixelflutWaveform - Revision history

Bertrik Sikken: Created page with "== The plan == The plan is to sample audio using a microphone, build a waveform display visualisation, send it over pixelflut to a display To sample audio, I plan to use an E..."