How to do it...

To do this, perform the following steps:

1. Run the following lines of code in the REPL:

>>> from adafruit_circuitplayground.express import cpx
>>> import time

1. The following block of code defines a list of color values that have the same values and sequence as that which appears in a rainbow:

>>> RAINBOW = [
... 0xFF0000,   # red
... 0xFFA500,   # orange
... 0xFFFF00,   # yellow
... 0x00FF00,   # green
... 0x0000FF,   # blue
... 0x4b0082,   # indigo
... 0xEE82EE,   # violet
... ]
>>> 

1. Then, set a more comfortable level of brightness and turn off all the pixels before starting the animation:

>>> cpx.pixels.brightness = 0.10
>>> cpx.pixels.fill(0x000000)
>>> 

1. Using the following block of code, loop through the seven colors in the rainbow and set one pixel to each color, with a brief delay of 0.2 seconds between each light change:

>>> for i, color in enumerate(RAINBOW):
...     cpx.pixels[i] = color
...     time.sleep(0.2)
...     
...     
... 
>>> 

1. Use the following animation to go back to each pixel and turn it off at the same rate of 0.2 seconds per light change:

>>> for i in range(len(RAINBOW)):
...     cpx.pixels[i] = 0x000000
...     time.sleep(0.2)
...     
...     
... 
>>> 

1. The following code combines all the steps described and wraps these into one infinite while loop. Add this section of code to the main.py file, and then create a continuous rainbow animation:

from adafruit_circuitplayground.express import cpx import time RAINBOW = [ 0xFF0000, # red 
 0xFFA500, # orange 
 0xFFFF00, # yellow 
 0x00FF00, # green 
 0x0000FF, # blue 
 0x4b0082, # indigo 
 0xEE82EE, # violet
]

cpx.pixels.brightness = 0.10
cpx.pixels.fill(0x000000)
while True:
    for i, color in enumerate(RAINBOW):
        cpx.pixels[i] = color
        time.sleep(0.2)
    for i in range(len(RAINBOW)):
        cpx.pixels[i] = 0x000000
        time.sleep(0.2)