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# Run this code when the script is called at the command line:

if __name__ == '__main__':

# Define the number of pixels in the NeoPixel strip.

# Only up to ~340 pixels can be written using the FT232H.

pixel_count = 16

# Create a NeoPixel_FT232H object.

pixels = NeoPixel_FT232H(pixel_count)

# Animate each pixel turning red.

# Loop through each pixel.

for i in range(pixel_count):

# Set the pixel color to pure red.

pixels.set_pixel_color(i, 255, 0, 0)

# Show the pixel buffer by sending it to the LEDs.

pixels.show()

# Delay for a short period of time.

time.sleep(0.25)

# Animate each pixel turning pure green.

for i in range(pixel_count):

pixels.set_pixel_color(i, 0, 255, 0)

pixels.show()

time.sleep(0.25)

# Animate each pixel turning pure blue.

for i in range(pixel_count):

pixels.set_pixel_color(i, 0, 0, 255)

pixels.show()

time.sleep(0.25)

# Animate a pattern of colors marching around the pixels.

# Create a pattern of colors to display.

colors = [ (255, 0, 0), (255, 255, 0), (0, 255, 0), (0, 255, 255),

(0, 0, 255), (255, 0, 255) ]

offset = 0

print 'Press Ctrl-C to quit.'

while True:

# Loop through all the pixels and set their color based on the pattern.

for i in range(pixel_count):

color = colors[(i+offset)%len(colors)]

pixels.set_pixel_color(i, color[0], color[1], color[2])

pixels.show()

# Increase the offset to make the colors change position.

offset += 1

time.sleep(0.25)

Save the file and navigate to the folder with it in a terminal, then execute the following in Windows to run the program:

python neopixels.py

Or on Mac OSX or Linux execute the following to run the program as root:

sudo python neopixels.py

You should see the NeoPixels light up and animate with different colors. Note that you might need to change the pixel_count

variable in the main part of the program to match the number of pixels in your NeoPixel strip, circle, matrix, etc.

This code does a couple things at a high level. It first defines a class called NeoPixel_FT232H. This class contains some

methods and state which control generating the NeoPixel signal with an FT232H board. The second part of the code uses the

NeoPixel_FT232H class to animate the NeoPixels.

You actually don't need to fully understand the NeoPixel_FT232H class code to use it. This code performs the 'oversampling' by

using a lookup table to expand each byte of color data into 8 bytes of SPI data that approximates the NeoPixel control signal. The

only important thing to know about the NeoPixel_FT232H class is that it exposes a set_pixel_color() function which allows you to

set the red, green, and blue color value of a pixel.

Instead let's walk through a bit of the second half of the code that uses the NeoPixel_FT232H class:

# Run this code when the script is called at the command line:

if __name__ == '__main__':

# Define the number of pixels in the NeoPixel strip.

# Only up to ~340 pixels can be written using the FT232H.

pixel_count = 16

# Create a NeoPixel_FT232H object.

pixels = NeoPixel_FT232H(pixel_count)