1  import time
 2  import board
 3  import neopixel
 4  
 5  
 6  # On CircuitPlayground Express, and boards with built in status NeoPixel -> board.NEOPIXEL
 7  # Otherwise choose an open pin connected to the Data In of the NeoPixel strip, i.e. board.D1
 8  pixel_pin = board.NEOPIXEL
 9  
10  # On a Raspberry pi, use this instead, not all pins are supported
11  # pixel_pin = board.D18
12  
13  # The number of NeoPixels
14  num_pixels = 10
15  
16  # The order of the pixel colors - RGB or GRB. Some NeoPixels have red and green reversed!
17  # For RGBW NeoPixels, simply change the ORDER to RGBW or GRBW.
18  ORDER = neopixel.GRB
19  
20  pixels = neopixel.NeoPixel(
21      pixel_pin, num_pixels, brightness=0.2, auto_write=False, pixel_order=ORDER
22  )
23  
24  
25  def wheel(pos):
26      # Input a value 0 to 255 to get a color value.
27      # The colours are a transition r - g - b - back to r.
28      if pos < 0 or pos > 255:
29          r = g = b = 0
30      elif pos < 85:
31          r = int(pos * 3)
32          g = int(255 - pos * 3)
33          b = 0
34      elif pos < 170:
35          pos -= 85
36          r = int(255 - pos * 3)
37          g = 0
38          b = int(pos * 3)
39      else:
40          pos -= 170
41          r = 0
42          g = int(pos * 3)
43          b = int(255 - pos * 3)
44      return (r, g, b) if ORDER in (neopixel.RGB, neopixel.GRB) else (r, g, b, 0)
45  
46  
47  def rainbow_cycle(wait):
48      for j in range(255):
49          for i in range(num_pixels):
50              pixel_index = (i * 256 // num_pixels) + j
51              pixels[i] = wheel(pixel_index & 255)
52          pixels.show()
53          time.sleep(wait)
54  
55  
56  while True:
57      # Comment this line out if you have RGBW/GRBW NeoPixels
58      pixels.fill((255, 0, 0))
59      # Uncomment this line if you have RGBW/GRBW NeoPixels
60      # pixels.fill((255, 0, 0, 0))
61      pixels.show()
62      time.sleep(1)
63  
64      # Comment this line out if you have RGBW/GRBW NeoPixels
65      pixels.fill((0, 255, 0))
66      # Uncomment this line if you have RGBW/GRBW NeoPixels
67      # pixels.fill((0, 255, 0, 0))
68      pixels.show()
69      time.sleep(1)
70  
71      # Comment this line out if you have RGBW/GRBW NeoPixels
72      pixels.fill((0, 0, 255))
73      # Uncomment this line if you have RGBW/GRBW NeoPixels
74      # pixels.fill((0, 0, 255, 0))
75      pixels.show()
76      time.sleep(1)
77  
78      rainbow_cycle(0.001)  # rainbow cycle with 1ms delay per step