LED Manager (Pico / Pico W)

This firmware drives one or more NeoPixel strips on a Raspberry Pi Pico or Pico W. Strips are segmented into named blocks that you can target over serial commands.

Config (config.json) The config is a JSON object with optional global keys and one or more pin blocks.

Optional global keys:

• STATUS_PIN: Heartbeat LED pin. Use "LED" on Pico W, or a GPIO number/"GPIOxx".
• RESET_BUTTON: GPIO pin for a physical reset button (active LOW, internal pull-up).

Pin blocks (required):

• Each top-level key is the GPIO pin driving a physical LED strip.
• Each value is a dictionary of named blocks mapped to [start, end] indices.
• Indices are local to that physical strip.

Example: { "STATUS_PIN": "LED", "RESET_BUTTON": "GPIO15", "GPIO28": { "front": [0, 22], "back": [23, 46] }, "GPIO2": { "left": [0, 10] } }

Notes:

• Strip names must be unique across all pins.
• If STATUS_PIN is omitted, it defaults to GPIO25 (Pico) / "LED" is preferred for Pico W.
• RESET_BUTTON is optional; if set, press to GND to reboot the board.

Commands and Behaviors Commands are read from stdin (USB serial). Each command must end with a semicolon (;). Multiple commands can be sent in one line, separated by semicolons. Commands are case-insensitive but are lowercased internally.

Targeting

• You can prefix a command with a strip name or "all".
• Example: "front color 255 0 0;" or "all brightness 0.5;"

Live mode

• "live 1;" enables LIVE mode (immediate apply).
• "live 0;" disables LIVE mode (staged changes, apply with "apply;").

Commands (control)

• start; Resume rendering (all strips).
• stop; Stop rendering and clear all LEDs.
• reset; Reinitialize config and hardware (soft reset of system state).
• apply; Apply staged changes (when live mode is off). apply N METHOD; Apply staged changes for N ms, then restore. METHOD: "off" (brightness to 0) or "last" (previous state). If METHOD is omitted, "last" is used.
• ping; No-op (useful for link testing).
• test N; Lights LED index N (local index) on any strip that has it; stops animation.

Commands (properties)

• color R G B [R G B ...]; Sets color points. Multiple triplets enable multi-color mode.
• color_mode MODE [PATTERN...]; Sets color rendering mode: simple, gradient, blocks, pattern. For pattern, provide one count per color (e.g., "color_mode pattern 3 2 5;").
• brightness V; Sets brightness (float, e.g., 0.0 to 1.0).
• mode N; Sets spatial mode.
• speed N; Sets animation speed (int).
• fade N; Sets fade time in ms.
• jitter N; Sets jitter amount (int).
• direction D; Sets direction ("right", "left", "pingpong").
• load_time N; Sets loading/progress bar duration in ms.

Behavior details

• With live mode OFF, property commands are staged and only take effect after "apply;".
• With live mode ON, property commands take effect immediately.
• "stop;" turns off LEDs and halts rendering until "start;".
• "reset;" rebuilds all strip instances and re-reads config.json.
• Heartbeat LED toggles every 500 ms.
• "apply N METHOD;" overrides any previous timed apply on the same strip.

Modes and Arguments Color behavior

• color with 1 RGB triplet: solid fill across the strip.
• color with multiple triplets: uses current color_mode (defaults to gradient).

Color modes (color_mode)

• simple: solid color only (used automatically when only 1 color is set).
• gradient: interpolate between colors across the strip.
• blocks: split the strip into equal blocks per color (no interpolation).
• pattern: repeat the provided per-color counts across the strip.

Spatial modes (mode N)

• 0: Static (no motion) - shows the current colors as-is.
• 1: Single moving pixel (uses current colors buffer).
• 2: Blink full buffer (on/off). Uses internal arg (default 5) as duty.
• 3: Random sparkle (density = internal arg, default 5).
• 4: Rotate buffer (scrolls colors across the strip).
• 5: Loading/progress bar (uses load_time for duration).

Arguments

• brightness V: float 0.0-1.0 or int 0-255 (both accepted).
• speed N: time in ms per tick step (lower = faster); 0 stops animation.
• fade N: color transition time in ms.
• jitter N: per-pixel random jitter (0 = off).
• direction D: "right", "left", or "pingpong" (anything else acts as pingpong).
• load_time N: loading bar duration in ms (mode 5 only).

Hardware reset button If RESET_BUTTON is set, the board reboots when the button is held LOW for ~50 ms. This resets I/O and forces USB serial to re-enumerate.