Use strand_length variable instead of a literal number

Author: jepler

CircuitPython_Pico_PIO_Neopixel/code.py

@@ -14,7 +14,7 @@
     num_strands=num_strands, auto_write=False, brightness=.18)
 
 # Make a virtual PixelMap so that each strip can be controlled independently
-strips = [PixelMap(pixels, range(i*30, (i+1)*30), individual_pixels=True)
+strips = [PixelMap(pixels, range(i*strand_length, (i+1)*strand_length), individual_pixels=True)
     for i in range(num_strands)]
 
 # This function makes a comet animation with slightly random settings