Flat Line

Art research project around sound and texture, by Marine Penhouet with Alexandre Bonhomme.

Devices

Each device is a self-contained PlatformIO firmware project with KiCad hardware in hardware/.

devices/beat/ — AD8232 ECG on XIAO RP2040. Dual-core: sampling + beat detection on core 0, SH1107 OLED on core 1. Beat-synced audio via PWM to a filtered mono jack. Custom PCB with Lipo Rider Plus power. Not a medical device.
devices/loop/ — Dual-core WAV player. Core 0 reads 16-bit stereo WAV from SD; core 1 streams I2S with pot-controlled pitch (0.1×–3×) and volume. MAX98357A amp, LiPo power. See POWER_BUDGET.md for runtime estimates.
devices/tape/ — Work in progress.
devices/harddrive/ — Work in progress.

Firmware: devices/<name>/src/, config in app_config.h, build via platformio.ini (seeed_xiao_rp2040).
Hardware: KiCad schematic and PCB under devices/<name>/hardware/.
Per-device docs: devices/<name>/README.md.

wav_converter.py — prepare WAV/MP3 for embedded playback (e.g. beat sample in include/blackhole.h).

Quick ffmpeg one-liner for 16-bit mono 44.1 kHz raw:

ffmpeg -i input.wav -ac 1 -ar 44100 -f s16le -acodec pcm_s16le output.raw