import time
import RPi.GPIO as GPIO
 
import Adafruit_WS2801
import Adafruit_GPIO.SPI as SPI
 
PIXEL_COUNT = 32

SPI_PORT   = 0
SPI_DEVICE = 0
pixels = Adafruit_WS2801.WS2801Pixels(PIXEL_COUNT, spi=SPI.SpiDev(SPI_PORT, SPI_DEVICE), gpio=GPIO)

def set_color(r, g, b):
    for i in range(pixels.count()):
        pixels.set_pixel(i, Adafruit_WS2801.RGB_to_color(r,g,b))
    pixels.show()

def clear_pixels():
    pixels.clear()
    pixels.show()

def main():
    DELAY = 0.1  
    r = 255
    g = 0
    b = 0

    while True:
        while r > 0:
            r = r-1
            g = g+1
            set_color(r,g,b)
            time.sleep(DELAY)
        while g > 0:
            g = g-1
            b = b+1
            set_color(r,g,b)
            time.sleep(DELAY)
        while b > 0:
            b = b-1
            r = r+1
            set_color(r,g,b)
            time.sleep(DELAY)

if __name__ == "__main__":
    main()