Fire / flicker neopixel ledstrip WS2812B

neopixel-flicker.py

#!/usr/bin/env python3
# Based off of http://www.walltech.cc/neopixel-fire-effect/ for Arduino
# Works with Raspbian Stretch on the RPi3

import time
from neopixel import *
import argparse

# LED strip configuration:
LED_COUNT      = 220      # Number of LED pixels.
LED_PIN        = 18      # GPIO pin connected to the pixels (18 uses PWM!).
#LED_PIN        = 10      # GPIO pin connected to the pixels (10 uses SPI /dev/spidev0.0).
LED_FREQ_HZ    = 800000  # LED signal frequency in hertz (usually 800khz)
LED_DMA        = 10      # DMA channel to use for generating signal (try 10)
LED_BRIGHTNESS = 255     # Set to 0 for darkest and 255 for brightest
LED_INVERT     = False   # True to invert the signal (when using NPN transistor level shift)
LED_CHANNEL    = 0       # set to '1' for GPIOs 13, 19, 41, 45 or 53

strip = Adafruit_NeoPixel(LED_COUNT, LED_PIN, LED_FREQ_HZ, LED_DMA, LED_INVERT, LED_BRIGHTNESS, LED_CHANNEL)
strip.begin()


while True:
  r = 255;
  g = 96;
  b = 12;
  
  for i in range(LED_COUNT):
    flicker = random.randint(0,40)
    r1 = r-flicker;
    g1 = g-flicker;
    b1 = b-flicker;
    if r1<0:
      r1 = 0;
    if g1<0:
      g1 = 0;
    if b1<0:
      b1 = 0;
    strip.setPixelColor(i,Color(r1,g1,b1))
  strip.show()
  time.sleep(random.uniform(0.05,0.15))

Nice! Next task: re-code for a matrix (eg 14x14) so every two lines get repeated (correct order / reversed per layout), and colour cools down for upper rows with random sparks of blue & white. ;-)