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.

Download the Adafruit CircuitPython Library Bundle

In order to run the code, we'll need to download a few libraries. Libraries contain code to help interface with hardware a lot easier for us.

Use the Adafruit M4 Express page on Installing Libraries to get the library that matches the major version of CircuitPython you are using noted above.

To run the code for this project, we need the three libraries in the Required Libraries list below. Unzip the library bundle and search for the libraries. Drag and drop the files into a folder named lib on the CIRCUITPY drive (which appears when your board is plugged into your computer via a known good USB cable) if the directory is not already on the Feather M4 Express).

Required Libraries 

  • neopixel.mpy
  • adafruit_led_animation

Once we have all the files we need, a directory listing will look similar to above as far as files and directories.

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

Click on the download link below to grab the project code directly from GitHub.

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

"""
This example uses AnimationsSequence to display multiple animations in sequence, at a five second
interval.

For NeoPixel FeatherWing. Update pixel_pin and pixel_num to match your wiring if using
a different form of NeoPixels.

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

from adafruit_led_animation.animation.rainbow import Rainbow
from adafruit_led_animation.animation.rainbowchase import RainbowChase
from adafruit_led_animation.animation.rainbowcomet import RainbowComet
from adafruit_led_animation.animation.rainbowsparkle import RainbowSparkle
from adafruit_led_animation.sequence import AnimationSequence

# 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)

rainbow = Rainbow(pixels, speed=0.1, period=2)
rainbow_chase = RainbowChase(pixels, speed=0.1, size=5, spacing=3)
rainbow_comet = RainbowComet(pixels, speed=0.1, tail_length=7, bounce=True)
rainbow_sparkle = RainbowSparkle(pixels, speed=0.1, num_sparkles=15)


animations = AnimationSequence(
    rainbow,
    rainbow_chase,
    rainbow_comet,
    rainbow_sparkle,
    advance_interval=5,
    auto_clear=True,
)

while True:
    animations.animate()

Adjust Code

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

If your NeoPixel strip uses more or less LEDs, you will change the number to reflect your setup.

# 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 = 84

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 different animation types and how to change attributes such as color, speed, size and spacing.

This guide was first published on Aug 12, 2020. It was last updated on Aug 12, 2020.

This page (Code) was last updated on Oct 23, 2021.

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