How to fix WS2812B RGB LEDs strip not work bug All In One

RGB / RGBW

how to clear ws2812b LED buffer data

如何清除 ws2812b LED buffer 数据

finally: clear buffer ✅

#!/usr/bin/env python3
# coding: utf8

from time import sleep
import board
import adafruit_dht

dhtDevice = adafruit_dht.DHT11(board.D17)
# dhtDevice = adafruit_dht.DHT11(board.D18)
# dhtDevice = adafruit_dht.DHT11(board.D18, use_pulseio=False)

print('开始读取温湿度 🌡 💦')

# once
def once():
  try:
    temperature_c = dhtDevice.temperature
    temperature_f = temperature_c * (9 / 5) + 32
    humidity = dhtDevice.humidity
    print("🌡 华氏温度 Temperature: {:.1f} °F ".format(temperature_f))
    print("🌡 摄氏温度 Temperature: {:.1f} °C".format(temperature_c))
    print("💦 湿度 Humidity: {}% ".format(humidity))
  except KeyboardInterrupt:
    print('Ctrl + C 退出 ✅')
  except RuntimeError as error:
    print("error =", error, error.args[0])
    pass
  except Exception as error:
    # dhtDevice.exit()
    raise error
  finally:
    sleep(2.0)
    dhtDevice.exit()
    # cleanup
    print('clear 🚀')

once()

https://www.cnblogs.com/xgqfrms/p/17406481.html

https://stackoverflow.com/questions/74167188/get-rid-of-lost-access-to-message-queue-in-a-simple-python-script/76264450#76264450

Adafruit_CircuitPython_NeoPixel

$ pip3 install adafruit-circuitpython-neopixel

$ sudo pip3 install adafruit-circuitpython-neopixel

https://github.com/adafruit/Adafruit_CircuitPython_NeoPixel#installing-from-pypi

import board
import neopixel

bugs ❌

Adafruit

https://github.com/adafruit/Adafruit_CircuitPython_NeoPixel/issues/151

pi@raspberrypi:~/Desktop $ vim ./neo-strip.py 
pi@raspberrypi:~/Desktop $ cat neo-strip.py 
#!/usr/bin/env python3
# coding: utf8

import board
import neopixel
from time import sleep


PIN = board.D18
# LEDs = 60
LEDs = 30
ORDER = neopixel.RGBW
pixels = neopixel.NeoPixel(PIN, LEDs, brightness=0.2, auto_write=False, pixel_order=ORDER)

# 60 LEDs
# pixels = neopixel.NeoPixel(board.D18, 60)
while True:
  for x in range(0, 60):
    # RGBW ❓
    # RGB
    pixels[x] = (255, 0, 0, 0)
    sleep(0.1)

"""
$ chmod +x ./led-strip.py
# ❌ Can't open /dev/mem: Permission denied
# $ ./led-strip.py

# ✅
$ sudo ./led-strip.py
"""
pi@raspberrypi:~/Desktop $ sudo ./neo-strip.py
Traceback (most recent call last):
  File "/home/pi/Desktop/./neo-strip.py", line 21, in <module>
    pixels[x] = (255, 0, 0, 0)
  File "/usr/local/lib/python3.9/dist-packages/adafruit_pixelbuf.py", line 310, in __setitem__
    self._set_item(index, r, g, b, w)
  File "/usr/local/lib/python3.9/dist-packages/adafruit_pixelbuf.py", line 274, in _set_item
    raise IndexError
IndexError
pi@raspberrypi:~/Desktop $

??? $ cat ./neo-strip.py ❌

#!/usr/bin/env python3
# coding: utf8

import board
import neopixel
from time import sleep

PIN = board.D18
# 0.3W/LED (03mA ~ 60mA)
# LEDs = 60
LEDs = 30
# mode: GRB 
ORDER = neopixel.GRB
pixels = neopixel.NeoPixel(PIN, LEDs, brightness=0.2, auto_write=True, pixel_order=ORDER)

while True:
  for x in range(0, LEDs):
    # GRB => Green
    pixels.fill((255,0, 0))
    pixels.show()
    sleep(0.5)
    # GRB => Red
    pixels[x] = (0, 255, 0)
    sleep(0.1)

"""
$ chmod +x ./led-strip.py
# ❌ Can't open /dev/mem: Permission denied
# $ ./led-strip.py

# ✅
$ sudo ./led-strip.py
"""

solution

电压不足，外接电源 ?

通道模式: GRB
LED 功率: 0.3W/每颗

Green Red Blue / Green Red Blue White

https://docs.circuitpython.org/projects/neopixel/en/latest/api.html#neopixel.GRB

??? 查询 neopixel API

点亮 LED 前，清空 buffer 数据？

clear

# clear buffer ???
pixels.fill((0,0, 0))

https://adafruit.github.io/Adafruit_NeoPixel/html/class_adafruit___neo_pixel.html#ae259682b202be0acd258d6879f4c7121

ws2812 - NodeMCU Documentation

https://nodemcu.readthedocs.io/en/1.5.4.1-final/modules/ws2812/

https://randomnerdtutorials.com/guide-for-ws2812b-addressable-rgb-led-strip-with-arduino/

`rpi_ws281x`

#!/usr/bin/env python3
# coding: utf8

from time import sleep
from rpi_ws281x import PixelStrip, Color

# LED strip configuration:
LED_COUNT = 60        # 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 a signal (try 10)
# LED_BRIGHTNESS = 50   # Set to 0 for darkest and 255 for brightest
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

# Create a NeoPixel object with the appropriate configuration.
strip = PixelStrip(LED_COUNT, LED_PIN, LED_FREQ_HZ, LED_DMA, LED_INVERT, LED_BRIGHTNESS, LED_CHANNEL)

# Initialize the library (must be called once before other functions).
strip.begin()
print("Test beginning ✅")

def clear_buffer():
  for i in range(LED_COUNT):
    strip.setPixelColor(i, Color(0, 0, 0))
  strip.show()
  sleep(1.0)

def rgb_test():
  # print("strip.numPixels() =", strip.numPixels())
  while True:
    for i in range(strip.numPixels()):
      # red led ✅
      strip.setPixelColor(i, Color(255, 0, 0))
      strip.show()
      sleep(0.1)
    sleep(1.0)
    for i in range(strip.numPixels()):
      # green led ✅
      strip.setPixelColor(i, Color(0, 255, 0))
      strip.show()
      sleep(0.1)
    sleep(1.0)
    for i in range(strip.numPixels()):
      # blue led ✅
      strip.setPixelColor(i, Color(0, 0, 255))
      strip.show()
      sleep(0.1)
    sleep(1.0)

try:
  rgb_test()
except KeyboardInterrupt:
  print('Ctrl + C exit ✅')
  clear_buffer()
except RuntimeError as error:
  print("error =", error, error.args[0])
  clear_buffer()
  pass
except Exception as error:
  print("exception =", error)
  clear_buffer()
  raise error

https://www.cnblogs.com/xgqfrms/tag/rpi_ws281x/

#!/usr/bin/env python3
# coding: utf8

print("Test ✅")

from time import sleep
from rpi_ws281x import PixelStrip, Color

# LED strip configuration:
LED_COUNT = 30        # 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 = 20   # Set to 0 for darkest and 255 for brightest
LED_INVERT = True     # 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

# Create NeoPixel object with appropriate configuration.
strip = PixelStrip(LED_COUNT, LED_PIN, LED_FREQ_HZ, LED_DMA, LED_INVERT, LED_BRIGHTNESS, LED_CHANNEL)

# Intialize the library (must be called once before other functions).
strip.begin()

# clear
for i in range(strip.numPixels()):
    strip.setPixelColor(i, Color(0, 0, 0))
strip.show()

sleep(1)

# Switch all pixels on
for i in range(strip.numPixels()):
    strip.setPixelColor(i, Color(255, 255, 255))
strip.show()

print("Test finished 🎉")
exit()

https://github.com/rpi-ws281x

https://github.com/rpi-ws281x/rpi-ws281x-python

https://github.com/rpi-ws281x/rpi-ws281x-python/tree/master/examples

https://github.com/rpi-ws281x/rpi-ws281x-python/blob/master/examples/neopixelclock.py#L48

rpi_ws281x API docs

pixelpi

https://pixelpi.readthedocs.io/en/latest/_modules/pixelpi/strip.html

clear

https://pixelpi.readthedocs.io/en/latest/library.html#pixelpi.Strip.clearLEDs

https://python.hotexamples.com/examples/rpi_ws281x/PixelStrip/begin/python-pixelstrip-begin-method-examples.html

REPL

https://www.runoob.com/try/runcode.php?filename=HelloWorld&type=python3

#!/usr/bin/python3

for i in range(0, 10):
  print("i =", i)

"""
i = 0
i = 1
i = 2
i = 3
i = 4
i = 5
i = 6
i = 7
i = 8
i = 9
"""
print("\n")
for i in range(0, 10, 2):
  print("step i =", i)

"""
step i = 0
step i = 2
step i = 4
step i = 6
step i = 8
"""

"""

range(stop)
range(start, stop[, step])

start: 计数从 start 开始。默认是从 0 开始。例如 range(5) 等价于 range(0， 5)
stop: 计数到 stop 结束，但不包括 stop。例如：range(0， 5) 是 [0, 1, 2, 3, 4] 没有 5
step：步长，默认为 1。例如：range(0， 5) 等价于 range(0, 5, 1)

https://www.runoob.com/python3/python3-func-range.html

"""

https://www.runoob.com/python3/python3-func-range.html

demos


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

# Simple test for NeoPixels on Raspberry Pi
import time
import board
import neopixel


# Choose an open pin connected to the Data In of the NeoPixel strip, i.e. board.D18
# NeoPixels must be connected to D10, D12, D18 or D21 to work.
pixel_pin = board.D18

# The number of NeoPixels
num_pixels = 30

# The order of the pixel colors - RGB or GRB. Some NeoPixels have red and green reversed!
# For RGBW NeoPixels, simply change the ORDER to RGBW or GRBW.
ORDER = neopixel.GRB

pixels = neopixel.NeoPixel(
    pixel_pin, num_pixels, brightness=0.2, auto_write=False, pixel_order=ORDER
)


def wheel(pos):
    # Input a value 0 to 255 to get a color value.
    # The colours are a transition r - g - b - back to r.
    if pos < 0 or pos > 255:
        r = g = b = 0
    elif pos < 85:
        r = int(pos * 3)
        g = int(255 - pos * 3)
        b = 0
    elif pos < 170:
        pos -= 85
        r = int(255 - pos * 3)
        g = 0
        b = int(pos * 3)
    else:
        pos -= 170
        r = 0
        g = int(pos * 3)
        b = int(255 - pos * 3)
    return (r, g, b) if ORDER in (neopixel.RGB, neopixel.GRB) else (r, g, b, 0)


def rainbow_cycle(wait):
    for j in range(255):
        for i in range(num_pixels):
            pixel_index = (i * 256 // num_pixels) + j
            pixels[i] = wheel(pixel_index & 255)
        pixels.show()
        time.sleep(wait)


while True:
    # Comment this line out if you have RGBW/GRBW NeoPixels
    pixels.fill((255, 0, 0))
    # Uncomment this line if you have RGBW/GRBW NeoPixels
    # pixels.fill((255, 0, 0, 0))
    pixels.show()
    time.sleep(1)

    # Comment this line out if you have RGBW/GRBW NeoPixels
    pixels.fill((0, 255, 0))
    # Uncomment this line if you have RGBW/GRBW NeoPixels
    # pixels.fill((0, 255, 0, 0))
    pixels.show()
    time.sleep(1)

    # Comment this line out if you have RGBW/GRBW NeoPixels
    pixels.fill((0, 0, 255))
    # Uncomment this line if you have RGBW/GRBW NeoPixels
    # pixels.fill((0, 0, 255, 0))
    pixels.show()
    time.sleep(1)

    rainbow_cycle(0.001)  # rainbow cycle with 1ms delay per step

https://docs.circuitpython.org/projects/neopixel/en/latest/examples.html

#!/usr/bin/env python3
# coding: utf8

from time import sleep
import board
import adafruit_dht

dhtDevice = adafruit_dht.DHT11(board.D17)
# dhtDevice = adafruit_dht.DHT11(board.D18)
# dhtDevice = adafruit_dht.DHT11(board.D18, use_pulseio=False)

print('开始读取温湿度 🌡 💦')

# once
def once():
  try:
    temperature_c = dhtDevice.temperature
    temperature_f = temperature_c * (9 / 5) + 32
    humidity = dhtDevice.humidity
    # print("Temperature: {:.1f} °F / {:.1f} °C".format(temperature_f, temperature_c))
    print("🌡 华氏温度 Temperature: {:.1f} °F ".format(temperature_f))
    print("🌡 摄氏温度 Temperature: {:.1f} °C".format(temperature_c))
    print("💦 湿度 Humidity: {}% ".format(humidity))
  except KeyboardInterrupt:
    print('Ctrl + C 退出 ✅')
  except RuntimeError as error:
    print("error =", error, error.args[0])
    pass
  except Exception as error:
    # dhtDevice.exit()
    raise error
  finally:
    sleep(2.0)
    dhtDevice.exit()
    # cleanup
    print('clear 🚀')

# infinite loop
def infinite():
  while True:
    try:
      temperature_c = dhtDevice.temperature
      temperature_f = temperature_c * (9 / 5) + 32
      humidity = dhtDevice.humidity
      # print("Temperature: {:.1f} °F / {:.1f} °C".format(temperature_f, temperature_c))
      print("🌡 华氏温度 Temperature: {:.1f} °F ".format(temperature_f))
      print("🌡 摄氏温度 Temperature: {:.1f} °C".format(temperature_c))
      print("💦 湿度 Humidity: {}% ".format(humidity))
    except KeyboardInterrupt:
      print('Ctrl + C 退出 ✅')
    except RuntimeError as error:
      print("error =", error, error.args[0])
      pass
    except Exception as error:
      # dhtDevice.exit()
      raise error
    finally:
      sleep(2.0)
      dhtDevice.exit()
      # cleanup
      print('clear 🚀')

once()
# infinite()

"""
https://www.cnblogs.com/xgqfrms/p/17406481.html

https://stackoverflow.com/questions/74167188/get-rid-of-lost-access-to-message-queue-in-a-simple-python-script/76264450#76264450

"""

(🐞 反爬虫测试！打击盗版⚠️）如果你看到这个信息, 说明这是一篇剽窃的文章，请访问 https://www.cnblogs.com/xgqfrms/ 查看原创文章！

final solution ✅

https://www.youtube.com/watch?v=4fF5joeQ2dY

$ vcgencmd get_throttled
throttled=0x0

disable audio snd_bcm2835 ✅

$ sudo vim /boot/config.txt

$ sudo cat /boot/config.txt

# Enable audio (loads snd_bcm2835)
# ✅ fix: https://github.com/adafruit/Adafruit_CircuitPython_NeoPixel/issues/151
# dtparam=audio=on

$ sudo reboot

$ sudo ./neopixel-strip-rgb.py
# OR
$ sudo ./pixel-strip-rgb.py

$ cat ./neopixel-strip-rgb.py

#!/usr/bin/env python3
# coding: utf8

import board
import neopixel
from time import sleep

# 60 LEDs
pixels = neopixel.NeoPixel(board.D18, 60)

def red_led_strip():
  for x in range(0, 60):
    pixels[x] = (255, 0, 0)
    sleep(0.1)
def green_led_strip():
  for x in range(0, 60):
    pixels[x] = (0, 255, 0)
    sleep(0.1)
def blue_led_strip():
  for x in range(0, 60):
    pixels[x] = (0, 0, 255)
    sleep(0.1)

def clear_buffer():
  for x in range(0, 60):
    pixels[x] = (0, 0, 0)

try:
  red_led_strip()
  sleep(1.0)
  green_led_strip()
  sleep(1.0)
  blue_led_strip()
  sleep(1.0)
except KeyboardInterrupt:
  print('Ctrl + C exit ✅')
except RuntimeError as error:
  print("error =", error, error.args[0])
  pass
except Exception as error:
  print("exception =", error)
  raise error
finally:
  print("after three seconds, auto clear buffer! 👻")
  sleep(3.0)
  # cleanup
  clear_buffer()
  print('clear 🚀')


"""
$ chmod +x ./neopixel-strip-rgb.
# ✅
$ sudo ./neopixel-strip-rgb.
"""

$ cat pixel-strip-rgb.py

#!/usr/bin/env python3
# coding: utf8

from time import sleep
from rpi_ws281x import PixelStrip, Color

# LED strip configuration:
LED_COUNT = 60        # 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 a signal (try 10)
# LED_BRIGHTNESS = 255   # Set to 0 for darkest and 255 for brightest
LED_BRIGHTNESS = 51   # 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

# Create a NeoPixel object with the appropriate configuration.
strip = PixelStrip(LED_COUNT, LED_PIN, LED_FREQ_HZ, LED_DMA, LED_INVERT, LED_BRIGHTNESS, LED_CHANNEL)

# Initialize the library (must be called once before other functions).
strip.begin()
print("Test beginning ✅")

def clear_buffer():
  for i in range(LED_COUNT):
    strip.setPixelColor(i, Color(0, 0, 0))
  strip.show()
  sleep(1.0)

def rgb_test():
  # print("strip.numPixels() =", strip.numPixels())
  while True:
    for i in range(strip.numPixels()):
      # red led ✅
      strip.setPixelColor(i, Color(255, 0, 0))
      strip.show()
      sleep(0.1)
    sleep(1.0)
    for i in range(strip.numPixels()):
      # green led ✅
      strip.setPixelColor(i, Color(0, 255, 0))
      strip.show()
      sleep(0.1)
    sleep(1.0)
    for i in range(strip.numPixels()):
      # blue led ✅
      strip.setPixelColor(i, Color(0, 0, 255))
      strip.show()
      sleep(0.1)
    sleep(1.0)

try:
  rgb_test()
except KeyboardInterrupt:
  print('Ctrl + C exit ✅')
  clear_buffer()
  sleep(2.0)
except RuntimeError as error:
  print("error =", error, error.args[0])
  clear_buffer()
  pass
except Exception as error:
  print("exception =", error)
  clear_buffer()
  raise error
finally:
  print("clear buffer ✅")
  clear_buffer()
  sleep(3.0)
"""
$ sudo ./pixel-strip-rgb.py
"""