1  """ FancyLED example for Circuit Playground Express using fastled_helpers
 2  """
 3  
 4  from adafruit_circuitplayground.express import cpx
 5  import adafruit_fancyled.fastled_helpers as helper
 6  
 7  cpx.pixels.auto_write = False  # Refresh pixels only when we say
 8  
 9  # A dynamic gradient palette is a compact way of representing a palette with
10  # non-equal spacing between elements.  This one's a blackbody palette with a
11  # longer red 'tail'.  The helper functions let us declare this as a list of
12  # bytes, so they're easier to copy over from existing FastLED projects.
13  # fmt: off
14  heatmap_gp = bytes([
15      0, 255, 255, 255,  # White
16      64, 255, 255, 0,  # Yellow
17      128, 255, 0, 0,  # Red
18      255, 0, 0, 0])  # Black
19  # fmt: on
20  
21  # Convert the gradient palette into a normal palette w/16 elements:
22  palette = helper.loadDynamicGradientPalette(heatmap_gp, 16)
23  
24  offset = 0  # Positional offset into color palette to get it to 'spin'
25  
26  while True:
27      for i in range(10):
28          # Load each pixel's color from the palette.  FastLED uses 16-step
29          # in-between blending...so for a 16-color palette, there's 256
30          # steps total.  With 10 pixels, multiply the pixel index by 25.5
31          # (and add our offset) to get FastLED-style palette position.
32          color = helper.ColorFromPalette(palette, int(offset + i * 25.5), blend=True)
33          # Apply gamma using the FastLED helper syntax
34          color = helper.applyGamma_video(color)
35          # 'Pack' color and assign to NeoPixel #i
36          cpx.pixels[i] = color.pack()
37      cpx.pixels.show()
38  
39      offset += 8  # Bigger number = faster spin