36 lines
1.3 KiB
Python
36 lines
1.3 KiB
Python
import board
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import neopixel
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try:
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import urandom as random # for v1.0 API support
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except ImportError:
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import random
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num_pix = 17 # Number of NeoPixels
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pix_pin = board.D1 # Pin where NeoPixels are connected
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strip = neopixel.NeoPixel(pix_pin, num_pix)
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min_alpha = 0.1 # Minimum brightness
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max_alpha = 0.4 # Maximum brightness
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alpha = (min_alpha + max_alpha) / 2 # Start in middle
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alpha_delta = 0.01 # Amount to change brightness each time through loop
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alpha_up = True # If True, brightness increasing, else decreasing
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strip.fill([0, 0, 255]) # Fill blue, or change to R,G,B of your liking
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while True: # Loop forever...
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if random.randint(1, 5) == 5: # 1-in-5 random chance
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alpha_up = not alpha_up # of reversing direction
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if alpha_up: # Increasing brightness?
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alpha += alpha_delta # Add some amount
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if alpha >= max_alpha: # At or above max?
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alpha = max_alpha # Limit to max
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alpha_up = False # and switch direction
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else: # Else decreasing brightness
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alpha -= alpha_delta # Subtract some amount
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if alpha <= min_alpha: # At or below min?
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alpha = min_alpha # Limit to min
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alpha_up = True # and switch direction
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strip.brightness = alpha # Set brightness to 0.0 to 1.0
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strip.write() # and issue data to LED strip
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