前言
树莓派在控制外部硬件设备上还真有那么些时候，今天就又踩到了（其实这里有越复杂的问题解决了）。
ws2812 网上一搜几乎都是用的 rpi-ws281x 看看这个库
安装
还是比较简单的
sudo pip3 install rpi-ws281x
官方
示例程序的示例程序，这是一个名为 strandtest.py 的示例程序
当然还有其他的示例程序
Github 链接
#!/usr/bin/env python3
# NeoPixel library strandtest example
# Author: Tony DiCola (tony@tonydicola.com)
#
# Direct port of the Arduino NeoPixel library strandtest example. Showcases
# various animations on a strip of NeoPixels.
import time
from rpi_ws281x import PixelStrip, Color
import argparse
# LED strip configuration:
LED_COUNT = 16 # 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
# Define functions which animate LEDs in various ways.
def colorWipe(strip, color, wait_ms=50):
"""Wipe color across display a pixel at a time."""
for i in range(strip.numPixels()):
strip.setPixelColor(i, color)
strip.show()
time.sleep(wait_ms / 1000.0)
def theaterChase(strip, color, wait_ms=50, iterations=10):
"""Movie theater light style chaser animation."""
for j in range(iterations):
for q in range(3):
for i in range(0, strip.numPixels(), 3):
strip.setPixelColor(i + q, color)
strip.show()
time.sleep(wait_ms / 1000.0)
for i in range(0, strip.numPixels(), 3):
strip.setPixelColor(i + q, 0)
def wheel(pos):
"""Generate rainbow colors across 0-255 positions."""
if pos < 85:
return Color(pos * 3, 255 - pos * 3, 0)
elif pos < 170:
pos -= 85
return Color(255 - pos * 3, 0, pos * 3)
else:
pos -= 170
return Color(0, pos * 3, 255 - pos * 3)
def rainbow(strip, wait_ms=20, iterations=1):
"""Draw rainbow that fades across all pixels at once."""
for j in range(256 * iterations):
for i in range(strip.numPixels()):
strip.setPixelColor(i, wheel((i + j) & 255))
strip.show()
time.sleep(wait_ms / 1000.0)
def rainbowCycle(strip, wait_ms=20, iterations=5):
"""Draw rainbow that uniformly distributes itself across all pixels."""
for j in range(256 * iterations):
for i in range(strip.numPixels()):
strip.setPixelColor(i, wheel(
(int(i * 256 / strip.numPixels()) + j) & 255))
strip.show()
time.sleep(wait_ms / 1000.0)
def theaterChaseRainbow(strip, wait_ms=50):
"""Rainbow movie theater light style chaser animation."""
for j in range(256):
for q in range(3):
for i in range(0, strip.numPixels(), 3):
strip.setPixelColor(i + q, wheel((i + j) % 255))
strip.show()
time.sleep(wait_ms / 1000.0)
for i in range(0, strip.numPixels(), 3):
strip.setPixelColor(i + q, 0)
# Main program logic follows:
if __name__ == '__main__':
# Process arguments
parser = argparse.ArgumentParser()
parser.add_argument('-c', '--clear', action='store_true', help='clear the display on exit')
args = parser.parse_args()
# 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()
print('Press Ctrl-C to quit.')
if not args.clear:
print('Use "-c" argument to clear LEDs on exit')
try:
while True:
print('Color wipe animations.')
colorWipe(strip, Color(255, 0, 0)) # Red wipe
colorWipe(strip, Color(0, 255, 0)) # Green wipe
colorWipe(strip, Color(0, 0, 255)) # Blue wipe
print('Theater chase animations.')
theaterChase(strip, Color(127, 127, 127)) # White theater chase
theaterChase(strip, Color(127, 0, 0)) # Red theater chase
theaterChase(strip, Color(0, 0, 127)) # Blue theater chase
print('Rainbow animations.')
rainbow(strip)
rainbowCycle(strip)
theaterChaseRainbow(strip)
except KeyboardInterrupt:
if args.clear:
colorWipe(strip, Color(0, 0, 0), 10)
测试
新建一个py文件，copy上面那个示例程序，使用命令行运行 (直接在IDE运行会报错，目前不知道解决办法)
比如 我建的名字为 test.py, 放在了桌面
cd Desktop
sudo python3 test.py
虽然没报错，但是灯是没有任何反应的，经过一番查找，在这里找到了原因，原来需要关闭音频输出。。。。。。
解决办法
打开终端运行
sudo nano /etc/modprobe.d/snd-blacklist.conf
添加下列语句
blacklist snd_bcm2835
ctrl+o保存 ctrl+x退出
修改conf.txt文件
sudo nano /boot/config.txt
找到下列语句(一般是在最下面)
# Enable audio (loads snd_bcm2835)
dtparam=audio=on
注释掉第二行
# Enable audio (loads snd_bcm2835)
#dtparam=audio=on
ctrl+o保存 ctrl+x退出
重启
sudo reboot
再次运行程序，可以成功点亮
前言
树莓派在控制外部硬件设备上还真有那么些时候，今天就又踩到了（其实这里有越复杂的问题解决了）。
ws2812 网上一搜几乎都是用的 rpi-ws281x 看看这个库
安装
还是比较简单的
sudo pip3 install rpi-ws281x
官方
示例程序的示例程序，这是一个名为 strandtest.py 的示例程序
当然还有其他的示例程序
Github 链接
#!/usr/bin/env python3
# NeoPixel library strandtest example
# Author: Tony DiCola (tony@tonydicola.com)
#
# Direct port of the Arduino NeoPixel library strandtest example. Showcases
# various animations on a strip of NeoPixels.
import time
from rpi_ws281x import PixelStrip, Color
import argparse
# LED strip configuration:
LED_COUNT = 16 # 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
# Define functions which animate LEDs in various ways.
def colorWipe(strip, color, wait_ms=50):
"""Wipe color across display a pixel at a time."""
for i in range(strip.numPixels()):
strip.setPixelColor(i, color)
strip.show()
time.sleep(wait_ms / 1000.0)
def theaterChase(strip, color, wait_ms=50, iterations=10):
"""Movie theater light style chaser animation."""
for j in range(iterations):
for q in range(3):
for i in range(0, strip.numPixels(), 3):
strip.setPixelColor(i + q, color)
strip.show()
time.sleep(wait_ms / 1000.0)
for i in range(0, strip.numPixels(), 3):
strip.setPixelColor(i + q, 0)
def wheel(pos):
"""Generate rainbow colors across 0-255 positions."""
if pos < 85:
return Color(pos * 3, 255 - pos * 3, 0)
elif pos < 170:
pos -= 85
return Color(255 - pos * 3, 0, pos * 3)
else:
pos -= 170
return Color(0, pos * 3, 255 - pos * 3)
def rainbow(strip, wait_ms=20, iterations=1):
"""Draw rainbow that fades across all pixels at once."""
for j in range(256 * iterations):
for i in range(strip.numPixels()):
strip.setPixelColor(i, wheel((i + j) & 255))
strip.show()
time.sleep(wait_ms / 1000.0)
def rainbowCycle(strip, wait_ms=20, iterations=5):
"""Draw rainbow that uniformly distributes itself across all pixels."""
for j in range(256 * iterations):
for i in range(strip.numPixels()):
strip.setPixelColor(i, wheel(
(int(i * 256 / strip.numPixels()) + j) & 255))
strip.show()
time.sleep(wait_ms / 1000.0)
def theaterChaseRainbow(strip, wait_ms=50):
"""Rainbow movie theater light style chaser animation."""
for j in range(256):
for q in range(3):
for i in range(0, strip.numPixels(), 3):
strip.setPixelColor(i + q, wheel((i + j) % 255))
strip.show()
time.sleep(wait_ms / 1000.0)
for i in range(0, strip.numPixels(), 3):
strip.setPixelColor(i + q, 0)
# Main program logic follows:
if __name__ == '__main__':
# Process arguments
parser = argparse.ArgumentParser()
parser.add_argument('-c', '--clear', action='store_true', help='clear the display on exit')
args = parser.parse_args()
# 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()
print('Press Ctrl-C to quit.')
if not args.clear:
print('Use "-c" argument to clear LEDs on exit')
try:
while True:
print('Color wipe animations.')
colorWipe(strip, Color(255, 0, 0)) # Red wipe
colorWipe(strip, Color(0, 255, 0)) # Green wipe
colorWipe(strip, Color(0, 0, 255)) # Blue wipe
print('Theater chase animations.')
theaterChase(strip, Color(127, 127, 127)) # White theater chase
theaterChase(strip, Color(127, 0, 0)) # Red theater chase
theaterChase(strip, Color(0, 0, 127)) # Blue theater chase
print('Rainbow animations.')
rainbow(strip)
rainbowCycle(strip)
theaterChaseRainbow(strip)
except KeyboardInterrupt:
if args.clear:
colorWipe(strip, Color(0, 0, 0), 10)
测试
新建一个py文件，copy上面那个示例程序，使用命令行运行 (直接在IDE运行会报错，目前不知道解决办法)
比如 我建的名字为 test.py, 放在了桌面
cd Desktop
sudo python3 test.py
虽然没报错，但是灯是没有任何反应的，经过一番查找，在这里找到了原因，原来需要关闭音频输出。。。。。。
解决办法
打开终端运行
sudo nano /etc/modprobe.d/snd-blacklist.conf
添加下列语句
blacklist snd_bcm2835
ctrl+o保存 ctrl+x退出
修改conf.txt文件
sudo nano /boot/config.txt
找到下列语句(一般是在最下面)
# Enable audio (loads snd_bcm2835)
dtparam=audio=on
注释掉第二行
# Enable audio (loads snd_bcm2835)
#dtparam=audio=on
ctrl+o保存 ctrl+x退出
重启
sudo reboot
再次运行程序，可以成功点亮
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