M5Stack-Fire Noise Synth & Visualizer

A handheld chaos machine that turns your M5Stack Fire into a pocket-sized noise lab, because silence is overrated and your neighbors had it too easy anyway.

Features

• 46 sound modes: White/Pink/Brown/Blue/Violet noises, classic waveforms, Shepard tones (up/down), FM/AM tricks, plucked strings, modal drums, granular, supersaw, PWM, ring-mod, chorus-ish, formants, sync, super-square, plus a grab bag of FX like bitcrush, phaser-ish comb, stutter/glitch, Doppler, gated reverb, aliasing buzz, etc. See src/types.cpp and include/types.h.
• Realtime oscilloscope: Visualizes the actual DAC waveform in the rectangle region on-screen.
• Shuffle mode: Auto-hops tracks on a timer so you can pretend it’s generative art and not button mashing.
• No-pop DAC handling: Starts/stops the speaker more politely than your average Bluetooth speaker.

Demos

• Short handheld clips of the app running on M5Stack Fire.

Note: GitHub does not render inline videos in README. The demo files are in static/. Use these links to watch them:

Hardware

• Board: M5Stack Fire (board = m5stack-fire)
• Audio: On-board speaker via DAC1 GPIO25 (AUDIO_DAC_PIN = 25)
• Display: Built-in TFT, landscape rotation

Key constants are in include/config.h:

• SAMPLE_RATE_HZ = 11025
• AUDIO_DAC_PIN = 25
• TRACK_COUNT = 46
• Visual area: NOISE_W = 280, NOISE_H = 160, positioned at (NOISE_X, NOISE_Y)
• Frame timing: FRAME_INTERVAL_MS = 67
• Shuffle: SHUFFLE_INTERVAL_MS = 12000

Build and Upload (PlatformIO)

• Uses Arduino framework and M5Stack library.
• Config: See platformio.ini ([env:m5stack-fire], platform = espressif32, framework = arduino, lib_deps = m5stack/M5Stack@^0.4.3, monitor_speed = 115200).

Steps:

1. Install VS Code + PlatformIO.
2. Connect the M5Stack Fire via USB. Select the correct serial port if needed.
3. Open this folder (m5stack-f25) in VS Code.
4. Build: PlatformIO: Build.
5. Upload: PlatformIO: Upload.
6. (Optional) Open Serial Monitor at 115200 baud to see logs.

Run/Controls

• On boot, the app shows track info and a waveform area.
• Buttons (printed on screen as a reminder):
  • A: short press → previous track. Hold → volume down (repeats).
  • B: short press → play/pause. Long press (~2s) → toggle Shuffle.
  • C: short press → next track. Hold → volume up (repeats).
• Current track name, shuffle state, and volume percent show in the header.

What you’re seeing/hearing

• Audio task: src/audio_synthesis.cpp runs on core 1 and writes 8-bit samples to DAC at SAMPLE_RATE_HZ.
• Waveform: src/visual_rendering.cpp reads a ring buffer (VIS_RING_SIZE = 1024) to draw the real output as an oscilloscope.
• Track mapping: src/types.cpp:getCurrentNoiseType() indexes into include/types.h:NoiseType (total TRACK_COUNT). Display names: getNoiseTypeName().
• Gain normalization: getGainForType() balances perceived loudness per mode; master gain is adjustable via A/C holds.

Adding new sounds

• Add a new enum to include/types.h:NoiseType.
• Map it to a track index and name in src/types.cpp (getCurrentNoiseType, getNoiseTypeName, getGainForType).
• Implement synthesis in src/audio_synthesis.cpp or extend src/audio_extras.cpp. If using extras, wire in via isExtraType() and nextAudioSampleExtra().
• The UI will automatically show your new mode when its track is selected.

Folder layout

• src/: main.cpp (UI/input), audio_synthesis.cpp (audio), visual_rendering.cpp (oscilloscope), types.cpp (track map), audio_extras.cpp (additional generators).
• include/: Headers (config.h, types.h, etc.).
• platformio.ini: Build target and dependencies.

Troubleshooting

• No sound: Ensure it’s a Fire (with speaker amp) and the device isn’t muted at OS level. Try volume holds (A to decrease, C to increase). Confirm DAC is GPIO25.
• Upload issues: Select the correct COM port in PlatformIO. Press and hold the reset/boot combo on the M5 if necessary.
• Crackles at start/stop: The code soft-lands the DAC, but tiny pops can happen. Let it settle a second after play/pause.
• LCD glitches: Keep default rotation and let the app paint the oscilloscope. Frame pacing is ~15 FPS (FRAME_INTERVAL_MS = 67).

Safety notes (seriously)

• Some modes get bright and/or piercing (e.g., near-Nyquist tones). Don’t crank it into headphones. Protect your hearing.
• Infrasound and thump modes are for fun, not medical therapy.

License

MIT License. See LICENSE for full text.