Coding

This project uses the LED animation rainbow example code from the CircuitPython LED Animation guide. The code is modified slightly to accommodate the additional pixels used in the sign.

The Mu Python Editor

Mu is a simple Python editor that works with Adafruit CircuitPython hardware. It's written in Python and works on Windows, MacOS, Linux and Raspberry Pi. The serial console is built right in, so you get immediate feedback from your board's serial output! While you can use any text editor with your code, Mu makes it super simple. Instructions for Mu are available here.

Installing or upgrading CircuitPython

You should ensure you have CircuitPython 5.0 or greater on your board. Plug your board in with a known good data + power cable (not the cheesy USB cable that comes with USB power packs, they are power only). You should see a new flash drive pop up.

If the drive is CIRCUITPY, then open the boot_out.txt file to ensure the version number is 5.0 or greater. 

Adafruit CircuitPython 5.3.1 on 2020-07-13; Adafruit Feather M4 Express with samd51j19

Installing Project Files

To use with CircuitPython, you need to first install a few libraries, into the lib folder on your CIRCUITPY drive. Then you need to update code.py with the example script.

Thankfully, we can do this in one go. In the example below, click the Download Project Bundle button below to download the necessary libraries and the code.py file in a zip file. Extract the contents of the zip file, open the directory examples/ and then click on the directory that matches the version of CircuitPython you're using and copy the contents of that directory to your CIRCUITPY drive.

Your CIRCUITPY drive should now look similar to the following image:

CIRCUITPY
# SPDX-FileCopyrightText: 2021 Kattni Rembor for Adafruit Industries
# SPDX-License-Identifier: MIT

"""
This example shows usage of the PixelMap helper to easily treat a single strip as a horizontal or
vertical grid for animation purposes.

For NeoPixel FeatherWing. Update pixel_pin and pixel_num to match your wiring if using
a different form of NeoPixels. Note that if you are using a number of pixels other than 32, you
will need to alter the PixelMap values as well for this example to work.

This example does not work on SAMD21 (M0) boards.
"""
import board
import neopixel

from adafruit_led_animation.animation.comet import Comet
from adafruit_led_animation.animation.rainbowcomet import RainbowComet
from adafruit_led_animation.animation.rainbowchase import RainbowChase
from adafruit_led_animation.animation.chase import Chase
from adafruit_led_animation.animation.rainbow import Rainbow
from adafruit_led_animation.sequence import AnimationSequence
from adafruit_led_animation import helper
from adafruit_led_animation.color import PURPLE, JADE, AMBER

# Update to match the pin connected to your NeoPixels
pixel_pin = board.D6
# Update to match the number of NeoPixels you have connected
pixel_num = 32

pixels = neopixel.NeoPixel(pixel_pin, pixel_num, brightness=0.5, auto_write=False)

pixel_wing_vertical = helper.PixelMap.vertical_lines(
    pixels, 8, 4, helper.horizontal_strip_gridmap(8, alternating=False)
)
pixel_wing_horizontal = helper.PixelMap.horizontal_lines(
    pixels, 8, 4, helper.horizontal_strip_gridmap(8, alternating=False)
)

comet_h = Comet(
    pixel_wing_horizontal, speed=0.1, color=PURPLE, tail_length=3, bounce=True
)
comet_v = Comet(pixel_wing_vertical, speed=0.1, color=AMBER, tail_length=6, bounce=True)
chase_h = Chase(pixel_wing_horizontal, speed=0.1, size=3, spacing=6, color=JADE)
rainbow_chase_v = RainbowChase(
    pixel_wing_vertical, speed=0.1, size=3, spacing=2, step=8
)
rainbow_comet_v = RainbowComet(
    pixel_wing_vertical, speed=0.1, tail_length=7, bounce=True
)
rainbow_v = Rainbow(pixel_wing_vertical, speed=0.1, period=2)
rainbow_chase_h = RainbowChase(pixel_wing_horizontal, speed=0.1, size=3, spacing=3)

animations = AnimationSequence(
    rainbow_v,
    comet_h,
    rainbow_comet_v,
    chase_h,
    rainbow_chase_v,
    comet_v,
    rainbow_chase_h,
    advance_interval=5,
)

while True:
    animations.animate()

Adjust Code

Look for the following lines in the code and adjust to fit the 8x8 NeoMatrix. Use any text editor or favorite IDE to modify the code. We suggest using Mu as noted above.

# Update to match the pin connected to your NeoPixels
pixel_pin = board.D6
# Update to match the number of NeoPixels you have connected
pixel_num = 64

pixel_wing_vertical = helper.PixelMap.vertical_lines(
    pixels, 8, 8, helper.horizontal_strip_gridmap(8, alternating=False)
)
pixel_wing_horizontal = helper.PixelMap.horizontal_lines(
    pixels, 8, 8, helper.horizontal_strip_gridmap(8, alternating=False)
)

Upload Code

Ensure the file is named code.py and drop it onto the CIRCUITPY drive main (root) directory that appears when your Feather is plugged into your computer via a known good USB data cable. The code will run properly when all of the files have been uploaded including libraries.

Customizing LED Animations

Take a moment to walk through the LED animation library for CircuitPython learn guide. The guide covers the how to create animations with horizontal and vertical grids.

This guide was first published on Aug 18, 2020. It was last updated on Aug 18, 2020.

This page (Code) was last updated on Aug 15, 2022.

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