KOSMOS v1.3.4

Generative Instrument for RP2040 + Waveshare Pico-Audio + Pico-LCD-1.3

KOSMOS is a self‑contained generative instrument built on the RP2040.
It combines:

• PRA32-U dual‑channel synthesizer (via Waveshare Pico-Audio)
• Pico-LCD-1.3 for real‑time visual feedback
• A custom generative engine that produces organic, breathing musical motion

Version v1.3.4 introduces a major upgrade to the step bar visualization, greatly improving clarity and musical awareness during performance.

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🎬 Demo Video

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✨ Features

🎹 Generative Engine

• Scale‑dependent behavior (HEI / MIYA / INSEN)
• Smooth, jumping, or deep expressive movement
• Randomized duration extension for “breathing” phrasing
• Dual‑channel PRA32-U synthesis (Main + Sub)
• USB MIDI output + internal MIDI bridge

🎨 Visual Feedback (v1.3.4)

The step bar now uses color-coded full-fill rendering to show pattern state, playhead position, and expressive timing.

Step Colors

Color	Meaning
G (Green)	Pattern ON (mainPattern[i] == 1)
W (Gray)	Pattern OFF (mainPattern[i] == 0)
R (Red)	Current step (playhead)
O (Orange)	Extended-duration note (A-part only)

Example

[W][G][W][G][W][G][W][G][W][G][W][G][W][G][W][G]
                               [R] ← current step
                               [O] ← extended note

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🆕 Improvements in v1.3.4

✔ 1. Full-Fill Step Rendering

All 16 steps are now drawn as solid blocks, eliminating visibility issues and ensuring stable rendering even during fast BPM.

✔ 2. Immediate Pattern Reflection

Whenever mainPattern[] changes, all steps are redrawn instantly, making pattern transitions visually obvious.

✔ 3. Expressive Timing Visualization (O = Orange)

When the A-part randomly extends a note’s duration, the current step briefly turns O (Orange).
This makes expressive timing changes visible and intuitive.

✔ 4. Smooth Behavior Without Visual “Hiccups”

The timing of R/O transitions has been refined to avoid conflicts between:

• step progression
• noteOn / noteOff
• duration extension

The result is a smooth, natural visual flow.

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🧠 Internal Architecture

Core1 (RP2040)

• PRA32-U synthesizer (Main + Sub)
• I2S audio output
• MIDI event queue processing

Core0

• KOSMOS generative engine
• Step sequencer
• Pattern generation
• LCD rendering
• USB MIDI output

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🎛 Controls

Button	Function
A	Program change (ch1)
B	Program change (ch2)
A + B	MIDI Start / Stop
X	Mute toggle (A / B / ALL)
Y	BPM cycle (20 / 80 / 140 / 200 / 260)
Joystick	Scale switching & future expansion

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🎼 Scales

Mode	Character
HEI	Bright, fast, jumping
MIYA	Emotional, slower
INSEN	Deep, traditional, sticky

Each scale changes:

• speed
• Movement width
• Direction behavior
• Duration extension probability

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📦 Hardware Requirements

• Raspberry Pi Pico
• Waveshare Pico-Audio
• Waveshare Pico-LCD-1.3
• USB MIDI (optional)
• 3.5mm audio output

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📁 Source Structure

/src
  ├── KOSMOS.ino
  ├── pra32-u-common.h
  ├── pra32-u-synth.h
  └── ...

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📝 License

MIT License

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🙌 Author

osamu — KOSMOS Project

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🌟 Special Thanks

• MATRIXSYNTH
• Powerd by ISGK Instruments PRA32-U