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LED Effects

raspbot.effects.light_effects.LightEffects

Animated LED effect engine built on top of LedBar.

Access via Robot.light_effects.

All effects are non-blocking. Start an effect with one of the start_* methods, then call update(ct) on every main-loop iteration to advance the animation. No time.sleep() or background threads are used.

Starting effects

start_river(speed=0.05)

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def start_river(self, speed: float = 0.05) -> None

Sequential chase-light cycling through all 7 colours. A sliding 3-LED window advances one step per frame.

Parameter Type Default Description
speed float 0.05 Seconds between each LED step

start_breathing(color=LedColor.BLUE, speed=0.01)

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def start_breathing(
    self,
    color: LedColor = LedColor.BLUE,
    speed: float = 0.01,
) -> None

Fade all LEDs in and out on a single colour.

Parameter Type Default Description
color LedColor BLUE Which colour to breathe
speed float 0.01 Seconds between brightness steps

start_random_running(speed=0.05)

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def start_random_running(self, speed: float = 0.05) -> None

Assign a random LedColor to every LED each frame.

Parameter Type Default Description
speed float 0.05 Seconds between frames

start_starlight(speed=0.1)

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def start_starlight(self, speed: float = 0.1) -> None

Randomly light a subset of LEDs each frame. The active colour cycles through all 7 colours, spending about one second on each.

Parameter Type Default Description
speed float 0.1 Seconds between frames

start_gradient(speed=0.02)

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def start_gradient(self, speed: float = 0.02) -> None

Fill LEDs one by one with a random saturated colour, then erase them one by one, repeating indefinitely.

Parameter Type Default Description
speed float 0.02 Seconds between each LED step

Tick and control

update(ct)

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def update(self, ct: float) -> None

Advance the current effect by one frame if enough time has elapsed.

Call this on every main-loop iteration with ct = time.monotonic(). It is cheap (a float comparison) when gated between frames.

Parameter Type Description
ct float Current time in seconds (from time.monotonic())

stop()

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def stop(self) -> None

Cancel the current effect and turn off all LEDs immediately.

off()

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def off(self) -> None

Alias for stop().

is_active

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@property
def is_active(self) -> bool

True while an effect is running.

Examples

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import time
from raspbot import Robot
from raspbot.types import LedColor

with Robot() as bot:
    # Start breathing blue -- returns immediately
    bot.light_effects.start_breathing(LedColor.BLUE, speed=0.01)

    while True:
        ct = time.monotonic()
        bot.light_effects.update(ct)   # advances one frame when due
        time.sleep(0.001)

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import time
from raspbot import Robot

with Robot() as bot:
    # Cycle through effects
    bot.light_effects.start_river(speed=0.05)
    start = time.monotonic()

    while True:
        ct = time.monotonic()
        bot.light_effects.update(ct)

        if ct - start > 10.0:
            bot.light_effects.start_starlight(speed=0.1)
            start = ct

        time.sleep(0.001)

See also