1  # CircuitPython demo - NeoPixel
 2  
 3  import time
 4  from adafruit_circuitplayground.express import cpx
 5  
 6  # The number of pixels in the strip
 7  numpix = 10
 8  
 9  
10  def wheel(pos):
11      # Input a value 0 to 255 to get a color value.
12      # The colours are a transition r - g - b - back to r.
13      if (pos < 0) or (pos > 255):
14          return (0, 0, 0)
15      if pos < 85:
16          return (int(pos * 3), int(255 - (pos*3)), 0)
17      if pos < 170:
18          pos -= 85
19          return (int(255 - pos*3), 0, int(pos*3))
20      pos -= 170
21      return (0, int(pos*3), int(255 - pos*3))
22  
23  
24  def rainbow_cycle(wait):
25      for j in range(255):
26          for i in range(cpx.pixels.n):
27              idx = int((i * 256 / len(cpx.pixels)) + j)
28              cpx.pixels[i] = wheel(idx & 255)
29          cpx.pixels.show()
30          time.sleep(wait)
31  
32  
33  cpx.pixels.auto_write = False
34  cpx.pixels.brightness = 0.3
35  while True:
36      rainbow_cycle(0.001)    # rainbowcycle with 1ms delay per step