树莓派控制WS2812

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4b配置过程

硬件连接

这个图只是个示意图，如果灯比较少直接树莓派5V供电

如果灯比较多，可以参看上图的外接供电

VCC-5v

gnd-gnd

vin-18引脚

环境配置

sudo apt-get update sudo apt-get install gcc make build-essential python-dev git scons swig 

下载源码

git clone https://github.com/jgarff/rpi_ws281x 

编译

cd rpi_ws281x/ sudo scons 

编译python版本

cd python sudo python setup.py build sudo python setup.py install 

examples文件夹下面是使用样例

标准测试样例

执行之前需要将编译的库拷贝过来 或者 运行程序直接添加环境

拷贝到测试样例

运行代码 必须从命令行以sudo 运行 否则报错

原理例成被我改了 未来使用必然配合别的程序，然而彩虹灯这样的效果需要占据一个线程

因此重新封装成一个类，并加入了多进程单独控制灯（线程本质上在树莓派还是一个线程）

如何使用

1新建一个工程，拷贝一个依赖文件到工程同目录

2把这个代码创建一个文件LED_Class放在同工程

详见后面LED_Class.py 文件

3要使用的test.py代码加入这个类

from LED_Class import LED

一定要从命令行 sudo 启动 text.py

from LED_Class import LED import time  led_use=LED() led_use.process_test() while 1:     print('这是主进程！')     time.sleep(2.0)#延迟2秒 

LED_Class.py 文件

#!/usr/bin/env python3  import time from neopixel import * import argparse from multiprocessing import Process  class LED(object):     def __init__(self):         LED_COUNT      = 8       # 灯的数目         LED_PIN        = 18      # pwm管教口 18引脚 树莓派.         #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         # 工艺参数         #parser = argparse.ArgumentParser()         #parser.add_argument('-c', '--clear', action='store_true', help='clear the display on exit')         #args = parser.parse_args()         # 创建LED控制对象         self.strip = Adafruit_NeoPixel(LED_COUNT, LED_PIN, LED_FREQ_HZ, LED_DMA, LED_INVERT, LED_BRIGHTNESS, LED_CHANNEL)         self.strip.begin()         print('LED初始化成功')     #功能一-逐个变色-      # colorWipe(self.strip, Color(255, 0, 0))  # Red wipe     # 所有灯逐个变成红色     def colorWipe(self,color, wait_ms=50):         """Wipe color across display a pixel at a time."""         for i in range(self.strip.numPixels()):             self.strip.setPixelColor(i, color)             self.strip.show()             time.sleep(wait_ms/1000.0)     #功能二-交替闪烁     # theaterChase(self.strip, Color(127, 127, 127))  # White     # 白色交替闪烁     def theaterChase(self, 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, self.strip.numPixels(), 3):                     self.strip.setPixelColor(i+q, color)                 self.strip.show()                 time.sleep(wait_ms/1000.0)                 for i in range(0, self.strip.numPixels(), 3):                     self.strip.setPixelColor(i+q, 0)     # 支撑函数     def wheel(self,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)     #功能三-彩虹色整体统一柔和渐变-每个灯颜色同一时间相同     def rainbow(self, wait_ms=20, iterations=1):         """Draw rainbow that fades across all pixels at once."""         for j in range(256*iterations):             for i in range(self.strip.numPixels()):                 self.strip.setPixelColor(i, self.wheel((i+j) & 255))             self.strip.show()             time.sleep(wait_ms/1000.0)     #功能四-彩虹色每一个灯各自柔和渐变-每个灯颜色同一时间不同     def rainbowCycle(self, wait_ms=20, iterations=5):         """Draw rainbow that uniformly distributes itself across all pixels."""         for j in range(256*iterations):             for i in range(self.strip.numPixels()):                 self.strip.setPixelColor(i, self.wheel((int(i * 256 / self.strip.numPixels()) + j) & 255))             self.strip.show()             time.sleep(wait_ms/1000.0)     #功能五-彩虹色统一闪烁流动变色-每个灯颜色同一时间相同     def theaterChaseRainbow(self,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, self.strip.numPixels(), 3):                     self.strip.setPixelColor(i+q, self.wheel((i+j) % 255))                 self.strip.show()                 time.sleep(wait_ms/1000.0)                 for i in range(0, self.strip.numPixels(), 3):                     self.strip.setPixelColor(i+q, 0)     #单进程全部函数测试     def test(self):                print ('Color wipe animations.')         self.colorWipe( Color(155, 0, 0))  # Red wipe         self.colorWipe( Color(0, 255, 0))  # Blue wipe         self.colorWipe( Color(0, 0, 255))  # Green wipe         print ('Theater chase animations.')         self.theaterChase( Color(127, 127, 127))  # White theater chase         self.theaterChase( Color(127,   0,   0))  # Red theater chase         self.theaterChase(Color(  0,   0, 127))  # Blue theater chase         print ('Rainbow animations.')         self.rainbow()         self.rainbowCycle()         self.theaterChaseRainbow()     #多进程全部函数测试         def process_test(self):         print('process_begin')         p= Process(target=self.test)         p.deamon=True         p.start()         print('process_end')          #-----------------------------        #LED函数初始化       #led_use=LED()  #1单个函数测试 #led_use.colorWipe(Color(100, 0, 0))  #2单进程全部函数测试 #led_use.test()  #3多进程全部函数测试 ''' led_use.process_test() while 1:     print('这是主进程！')     time.sleep(2.0)#延迟2秒 '''