How to Control RGBWW LED Strips with Raspberry Pi

				
					#!/usr/bin/env python3
import RPi.GPIO as GPIO
from rpi_ws281x import PixelStrip, Color
import time
import math
import signal
import sys

# === hardware setup ===
# WS2812B RGB led strip
RGB_LED_COUNT = 100 # LED quantity
RGB_PIN = 18            # data PIN
RGB_BRIGHTNESS = 80     # brightness（0-255）

# white CCT LED strip（cold white CW + warm white WW）
CW_PIN = 13             # cold white PWM PIN
WW_PIN = 12             # warm white PWM PIN
CCT_FREQ = 1000         # PWM frequency（Hz）

# === formation ===
# RGB LED strip
strip = PixelStrip(RGB_LED_COUNT, RGB_PIN, brightness=RGB_BRIGHTNESS)
strip.begin()

# white CCT
GPIO.setmode(GPIO.BCM)
GPIO.setup([CW_PIN, WW_PIN], GPIO.OUT)
pwm_cw = GPIO.PWM(CW_PIN, CCT_FREQ)
pwm_ww = GPIO.PWM(WW_PIN, CCT_FREQ)
pwm_cw.start(0)
pwm_ww.start(0)

# === core effect function ===
def wheel(pos):
    """generate rainbow Color（0-255 input）"""
    pos = 255 - pos  # reverse color_direction（optional）
    if pos < 85:
        return Color(pos * 3, 255 - pos * 3, 0)
    elif pos < 170:
        pos -= 85
        return Color(255 - pos * 3, 0, pos * 3)
    else:
        pos -= 170
        return Color(0, pos * 3, 255 - pos * 3)

def flowing_rainbow_with_cct(speed_ms=30):
    """recycle running rainbow flow + dynamic color temperature"""
    step = 0
    while True:  # endless recycle
        # dynamic color temperature（2500K~6500K sine fluctuation）
        kelvin = 2500 + int(4000 * (0.5 + 0.5 * math.sin(step * 0.015)))
        set_cct(kelvin)
        
        # rainbow_flowing effect（color phase of every LED remove）
        for i in range(strip.numPixels()):
            hue = int((i * 5 + step) % 256)  # adjust 5 control wave density
            strip.setPixelColor(i, wheel(hue))
        
        strip.show()
        time.sleep(speed_ms / 1000.0)
        step += 1

def set_cct(kelvin):
    """setup color temperature（2500K-6500K）"""
    kelvin = max(2500, min(kelvin, 6500))
    if kelvin <= 4000:
        ww = 100 - (kelvin - 2500) / 15
        cw = 0
    else:
        cw = (kelvin - 4000) / 25
        ww = 0
    pwm_cw.ChangeDutyCycle(cw)
    pwm_ww.ChangeDutyCycle(ww)

# === escape safely ===
def signal_handler(sig, frame):
    print("\nclose light...")
    for i in range(strip.numPixels()):
        strip.setPixelColor(i, Color(0, 0, 0))
    strip.show()
    pwm_cw.ChangeDutyCycle(0)
    pwm_ww.ChangeDutyCycle(0)
    GPIO.cleanup()
    sys.exit(0)

signal.signal(signal.SIGINT, signal_handler)

# === main program ===
if __name__ == '__main__':
    try:
        print("addressable flowing running (Ctrl+C stop)...")
        flowing_rainbow_with_cct(speed_ms=25)  # speed adjustable
    except KeyboardInterrupt:
        signal_handler(None, None)