CircuitPython with the CPX

code.py

#!/usr/bin/python
# CPX Light Effects program. Copyright (c) 2022 by Elk Grove Village Public Library. 
# Licensed under the [GNU General Public License, version 3](https://www.gnu.org/licenses/gpl-3.0.en.html).

from adafruit_circuitplayground.express import cpx
import time

wait_time = 0.05
pixel_count = 10

def fill(color_value):
    for pixel in range( 0, pixel_count, 1 ):
        cpx.pixels[pixel] = color_value
        time.sleep(wait_time)
    time.sleep(wait_time)
    for pixel in range( pixel_count-1, -1, -1 ):
        cpx.pixels[pixel] = (0,0,0)
        time.sleep(wait_time)

def scanner(color_value):
    red_value = color_value[0]
    green_value = color_value[1]
    blue_value = color_value[2]
    temp = round(pixel_count/2)
    low_r = round(red_value/255)
    low_g = round(green_value/255)
    low_b = round(blue_value/255)
    med_r = round(red_value/4)
    med_g = round(green_value/4)
    med_b = round(blue_value/4)
    for n in range (0,10,1):
        cpx.pixels[0] = (red_value, green_value, blue_value)
        cpx.pixels[5] = (red_value, green_value, blue_value)
        for i in range(1, temp, 1):
            time.sleep(wait_time)
            cpx.pixels[i] = (red_value, green_value, blue_value)
            cpx.pixels[i-1] = (low_r, low_g, low_b)
            cpx.pixels[i+temp] = (red_value, green_value, blue_value)
            cpx.pixels[i+temp-1] = (low_r, low_g, low_b)
        time.sleep(wait_time)
        cpx.pixels[temp-1] = (low_r, low_g, low_b)
        cpx.pixels[pixel_count-1] = (low_r, low_g, low_b)

while True:
    if cpx.button_a:
        cpx.start_tone(440)
        fill( (0,0,255) ) # blue
        cpx.stop_tone()
    elif cpx.button_b:
        cpx.start_tone(880)
        fill( (0,255,0) ) # green
        cpx.stop_tone()
    elif cpx.touch_A1:
        scanner( (255,255,0) )
    elif (cpx.light <= 10):
        for i in range(0,10,1):
            cpx.play_tone(1000,0.01)
    else:
        fill( (255,0,0) ) # red

notes.md

CircuitPython with the Circuit Playground Express

You can also test for other things on the CPX. Here, the CPX will beep ten times if you hold your hand over it using cpx.light.

We've also added a slightly more challenging piece of code: a new method, called scanner(), which creates a different effect when you're touching A1 (using cpx.touch_A1) at the start of the loop. Feel free to dig through the code and figure out how it works.

There are lots of fun things you can do with CircuitPython. Enjoy and explore!