104 lines
2.9 KiB
Markdown
104 lines
2.9 KiB
Markdown
# terminal-oscilloscope
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A terminal-based oscilloscope with CRT phosphor physics, written in Nim. Zero dependencies — 200KB binary, just libc.
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## Braille renderer (amber palette)
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## Half-block renderer
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## Features
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- **CRT boot/shutdown animations** — phosphor ramp, beam sweep, vertical collapse, dot fade
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- **Y-T and X-Y modes** — time-domain waveform or Lissajous figures
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- **Phosphor persistence** — beam bloom, decay trails, intensity-based shading
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- **Two renderers** — half-block (`▀▄█`) or braille dots for 4× resolution
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- **Live audio capture** — direct libav bindings via dlopen, zero install
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- **Threaded audio** — 60fps rendering, audio capture on separate thread
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- **6 CRT phosphor palettes** — green, amber, cyan, blue, white, red
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## Install
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Requires [Nim](https://nim-lang.org/) 2.x.
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```bash
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git clone https://github.com/rolandnsharp/terminal-oscilloscope.git
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cd terminal-oscilloscope
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```
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**Half-block version** (chunky CRT look):
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```bash
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nim c -d:release --threads:on -o:osc src/osc.nim
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./osc
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```
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**Braille version** (high-resolution dots):
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```bash
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nim c -d:release --threads:on -o:osc_braille src/osc_braille.nim
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./osc_braille
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```
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**Install globally:**
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```bash
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sudo ln -s $(pwd)/osc /usr/local/bin/osc
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```
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## Controls
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| Key | Action |
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|-----|--------|
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| `m` | Toggle Y-T / X-Y mode |
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| `+` / `-` | Increase / decrease gain (amplitude) |
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| `]` / `[` | Zoom in / out time axis |
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| `q` | Quit (with CRT shutdown effect) |
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## Configuration
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Runtime options can be passed via CLI flags:
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```bash
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./osc --palette:amber --decay:0.92 --beam:0.6 --bloom:0.12
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./osc_braille --palette:green --hot:0.8 --warm:0.45 --cool:0.12
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```
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Available options:
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| Option | Description | Default |
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|--------|-------------|---------|
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| `-p`, `--palette:NAME` | Palette name | `green` |
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| `-d`, `--decay:FLOAT` | Phosphor persistence per frame | `0.85` |
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| `--beam:FLOAT` | Beam impact intensity | `0.4` |
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| `--bloom:FLOAT` | Horizontal glow spread | `0.08` |
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| `--hot:FLOAT` | White-hot beam core threshold | `0.7` |
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| `--warm:FLOAT` | Bright phosphor threshold | `0.4` |
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| `--cool:FLOAT` | Dim persistence trail threshold | `0.15` |
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Show help:
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```bash
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./osc --help
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./osc_braille --help
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```
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### Palettes
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| Name | Phosphor | Look |
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|------|----------|------|
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| `green` | P31 | classic oscilloscope |
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| `amber` | P12 | warm retro terminal |
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| `cyan` | P7 | Tektronix blue-green |
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| `blue` | P11 | cool/modern |
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| `white` | P4 | TV phosphor |
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| `red` | P22-R | radar display |
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## Audio
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Captures system audio by opening the PulseAudio/PipeWire monitor of your default output sink directly via libavformat and libavdevice. Libraries are loaded at runtime with `dlopen` — no dev packages, no subprocess, no extra dependencies.
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## Credits
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CRT turn-on/off animations inspired by [AetherTune](https://github.com/nevermore23274/AetherTune).
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